Sunday, November 25, 2007

New Light On Early Formation Of Earth And Mars

A team of scientists from NASA's Johnson Space Center (JSC) and the Lunar and Planetary Institute and the University of California, Davis (UCD) has found that terrestrial planets such as the Earth and Mars may have remained molten in their early histories for tens of millions of years. The findings indicate that the two planets cooled slower than scientists thought and a mechanism to keep the planet interiors warm is required.

These new data reveal that the early histories of the inner planets in the solar system are complex and involve processes no longer observed. Evidence of these processes has been preserved in Mars, while it has been erased in Earth. So Mars is probably the best opportunity to understand how Earth formed.

The formation of the solar system can be dated quite accurately to 4,567,000,000 years ago, said Qing-Zhu Yin, assistant professor of geology at UC Davis and an author on a new paper. Mars' metallic core formed a few million years after that. Previous estimates for how long the surface remained molten ranged from thousands of years to several hundred million years.

The persistence of a magma ocean on Mars for 100 million years is "surprisingly long," Yin said. It implies that at the time, Mars must have had a thick enough atmosphere to insulate the planet and slow down cooling, he said.

Scientists think that early crust formation alone cannot account for the slow cooling magma ocean seen in large planets. This new evidence instead implies that Mars, at one time, had a primitive atmosphere that acted as the insulator. “The primitive atmosphere was composed mostly of hydrogen left over from accretion into a rocky planet, but was removed, probably by impacts, about 100 million years after the planet formed,” said Debaille.

Debaille and her colleagues performed precise measurements of neodymium isotope compositions of nine rare Martian meteorites called shergottites using mass spectrometers at JSC and UCD. Shergottites, named after the first-identified meteorite specimen that fell at Shergotty, India, in 1865, are a group of related meteorites from Mars composed primarily of pyroxene and feldspar.

The scientists examined shergottites because their large range in chemical compositions is thought to be a fingerprint of the formation of their deep sources very early in the history of Mars.

“These rocks were lavas that were made by melting deep in Mars and then erupted on the surface," said Brandon. “They were delivered to Earth as meteorites following impacts on Mars that exhumed them and launched them into space." Mars meteorites are a treasure chest of information about that planet and have been the focus of extensive research by scientists.

The metallic element samarium has two radioactive isotopes that decay at a known rate to two daughter neodymium isotopes. By precisely measuring the quantities of neodymium isotopes, Debaille was able to use these two radiometric clocks to derive the times of formation of the different shergottite sources in the Martian interior.

“We expected to find that their sources all formed at the same time,” said Debaille. “But what we found instead was that the shergottite sources formed at two different times. The oldest formed at 35 million years after the solar system began to condense from ice and dust into large planets about 4,567 million years ago. The youngest formed about 110 million years after the solar system began to condense.”

Debaille and her colleagues found that the scenario that best fits the data is one where a global-scale magma ocean formed from melting in Mars during the final stages of accretion and then slowly solidified over this time period.

“The most recent physical models for magma oceans suggest they solidify on timescales of a few million years or less, so this result is surprising,” said Brandon. “Some type of insulating blanket, either as a rocky crust or a thick atmosphere, is needed as an insulator to have kept the Martian interior hot.”

Tuesday, November 20, 2007

Sun may be smaller than thought


The Sun may be smaller than we thought, a new study argues.

If correct, then other properties of the Sun such as its internal temperature and density may be slightly different than previously calculated. Understanding the Sun's interior is important as it might help scientists make predictions about space weather and answer questions about the solar system.

The Sun has no solid surface. Its atmosphere merely gets thinner and more transparent farther from its centre.

Instead the Sun's "surface" is defined to be the depth in the Sun's atmosphere where it becomes opaque to light. Scientists measure this by observing the Sun with telescopes and measuring the distance between the centre of the Sun's disc and its "edge" – the place where its brightness suddenly drops off. This gives a radius of 695,990 kilometres, or about 109 times the radius of Earth.

A second, completely different way to measure the Sun's size is by using surface gravity waves called f-modes that ripple across the surface of the Sun like water waves on the ocean.

Multiple choice

Theory implies that these waves should appear only at the Sun's opaque surface, and observations of them can be used to measure the Sun's radius, since their wavelength is tied to their distance from the Sun's centre in a predictable way.

Scientists have been puzzled for years because these methods give two different answers. The wave method gives a radius of around 695,700 kilometres, about 300 kilometres smaller than the result from the light drop-off measurement.

Although the difference amounts to just 0.04%, it is large enough to matter when scientists try to gain insights on the Sun's interior by interpreting observations of sound waves – which ripple the Sun's surface in addition to the f-modes – using a technique called helioseismology.

Understanding the Sun through helioseismology is important as it can help scientists learn about the origins of the magnetic fields that produce sunspots, which in turn can help predict space weather.

Helioseismology has also helped scientists understand some of the mysteries of the solar system – for example, the technique was used to solve part of the solar neutrino problem. The technique ruled out changes in the Sun's interior as a cause of this mysterious disappearance of neutrinos flowing from the Sun to Earth.

Real difference

Now, new calculations of how light propagates in the Sun's atmosphere may have resolved the discrepancy in the Sun's radius in favour of the smaller measurement. The new calculations were carried out by a team led by Margit Haberreiter of the World Radiation Centre in Davos, Switzerland.

The team recalculated the precise spot where the light drop-off should occur, using software that simulates the propagation of light through the Sun's atmosphere developed by Haberreiter and her colleague Werner Schmutz, also at the WRC.

Their results suggest there should actually be a small difference between where the Sun's atmosphere becomes opaque and the point where observers see the light drop-off.

The light drop-off happens 333 kilometres higher up in the Sun's atmosphere than the location of the opaque surface where the f-modes occur, according to their calculations.

Theoretical models of the Sun that are based on the larger radius need to be corrected, the authors say. A more accurate radius could lead to a better understanding of the Sun's interior, says team member Alexander Kosovichev of Stanford University in California, US.

Incomplete knowledge
"It allows us to calculate more accurately the structure of the Sun and compare with the results of helioseismology, learning more about the constitution of the Sun,"

He points out recent observations that suggest the Sun contains only half as much oxygen as previously believed, which appears to conflict with the results of sound wave studies. "Something is still missing in our understanding of the solar interior," he says.

Sarbani Basu of Yale University in New Haven, Connecticut, US, who was not involved in the research, says it is an open question whether the new radius Haberreiter's team propose is the right one. But she agrees that pinpointing the Sun's radius more exactly would help make more reliable calculations of conditions in the Sun's interior.

"For the Sun, all our measurements are so precise, even if it's a few hundred kilometres difference … [it] is a big deal"

Sunday, November 18, 2007

Chandra Sees Star Formation in NGC 281


Here's a short little post about the star forming nebula NGC 281, captured by NASA's Chandra X-Ray Observatory. This photograph is actually a composite of several wavelengths, imaged by ground and space-based observatories.

The optical data (red, orange and yellow) shows the clouds of gas and dust, and the dark lanes of obscuring dust where stars may be forming. The Chandra X-Ray data is in purple, and reveals more than 300 individual X-ray sources - most of them are associated with the central star forming region.

There's another group of X-ray sources on the other side of the molecular cloud. Based on the elements in the region, astronomers think that a supernova went off in the region recently.

But really, it's a pretty picture.

Prototype Heat Sheild for Orion


It's a prototype heat shield, developed by Boeing for NASA's Orion Crew Exploration Vehicle.

When Orion returns from space, it needs to decelerate from orbital velocity to be able to land safely. Just like the space shuttle, the capsule will point this heat ablating surface into the atmosphere, and let it get super hot. The heat shield can rise to extremely high temperatures, while the astronauts stay nice and safe.

The lunar protective system will need to be much more capable that the shuttle's system, since capsules will be returning directly to the Earth after flying from the Moon. In some cases, Orion's thermal protection will face 5 times as much heat as vehicles returning from the International Space Station. That's hot.

It was the catastrophic failure of Columbia's heat shield that doomed it when it was re-entering the Earth's atmosphere. Needless to say, NASA wants to get this right.

The contract for the new Thermal Protection System was awarded to Boeing Advanced Systems about a year ago. Last month, a NASA Ames technical and quality inspection team completed an acceptance review of the shield.

The shield is made from Phenolic Impregnated Carbon Ablator (PICA). That's a mouthful, but it uses a special trick to keep the capsule cool. As the heat shield heats up during reentry, the PICA material "ablates". It chars, melts and then sublimates to create a cool boundary layer that protects the spacecraft.

Boeing will continue working on the heat shield, to meet Orion's TPS preliminary design review in early 2008.

NASA Tests New Parachutes for Ares Spacecraft


This has been an exciting week for NASA’s Constellation program – the missions that will bring humans back to the moon. Earlier in the week, NASA announced plans for testing abort systems and inflatable moon habitats.

But on Thursday, November 15 actual tests were conducted for some of the genuine hardware that will be used for the Ares launch vehicles.

Near Yuma, Arizona, engineers tested the parachutes that will bring boosters from the first stage of the massive Ares rockets back to Earth.

Certainly, parachutes and rocket booster recovery is nothing new for NASA. But this new parachute is a whopper. Spanning 150 feet across and weighing 2,000 pounds makes this the largest chute of its kind ever tested for parachutes that will carry some of the heaviest payloads ever delivered.

And the new parachute worked perfectly, if not patriotically, with its red, white and blue striped canopy. Made of Kevlar, which is stronger and lighter than the nylon chutes used for the space shuttle’s solid rocket booster recovery, these bigger and stronger parachutes can still fit into the same size canister used for the shuttle boosters but yet be lighter.

Although the Ares boosters will actually come down in the Atlantic Ocean, the tests were conducted in the desert near the U.S. Army’s Yuma Proving Ground. Additionally, the tests used only a 42,000 pound weighted tub as opposed to the 200,000 pound weight of the actual boosters. But the drop tests from 16,000 ft. from a C-17 airplane simulated the peak loads at parachute opening and measured the drag area to validate the design.

The parachute system will allow the Ares I and Ares V boosters to be recovered and then refurbished and reused for future flights. Ares I will launch the Orion vehicle, which will carry humans to the moon, while the larger Ares V will be used for the Cargo Launch Vehicle.

The boosters are scheduled to be flight tested in 2009.

Thursday, November 15, 2007

Planets Found Forming in the Pleiades Star Cluster


As you gaze up at the familiar Pleiades star cluster, here's something new you can think about. Planets recently collided around two of the stars in the cluster, kicking up vast clouds of dust. New worlds are being formed, and destroyed, right before our very eyes. At least, if you've got the help from some of the most powerful telescopes on Earth, and in space.

This announcement was made by a team of astronomers using the Gemini Observatory in Hawaii and the Spitzer Space Telescope. Their findings will be published in an upcoming issue of the Astrophysical Journal.

The Pleiades star cluster - located in the constellation Taurus - is one of the most famous objects in the night sky. Easily visible to the unaided eye, it's even more spectacular in binoculars or a small telescope. Although it's often referred to as the "seven sisters", the cluster actually contains 1,400 stars, in various stages of formation.

One of the stars, known as HD 23514, has a little more mass than our Sun. The astronomers discovered that it's surrounded by an enormous disk of hot dust particles. Astronomers think that this is the debris from a planetary collision.

It's believed that these dust particles, the building blocks of planets, accumulate into comets and asteroid-size bodies and then clump together into larger and larger objects. This is a violent process, though. Some objects get bigger, and others collide, shattering into dust that astronomers can detect.

Astronomers think that this is a similar process that led to the formation of the Earth's moon. At some point in the early Solar System, a Mars-sized object collided with the Earth. The debris from that collision became the Earth and the Moon.

Two stars in the Pleiades cluster, HD 23514 and BD +20 307, are thought to be in this stage of evolution. They're between 100 and 400 million years old. Much younger stars can have this dust when they're 10 million years old, but it's usually dissipated by the time a star reaches 100 million years old. It takes enormous planetary collisions to get the dust spewing out again.

Hubble's View of Comet Holmes


Comet Holmes, which is now larger than the Sun. But don't get fooled. That beautiful image on the left was taken by amateur astronomer Alan Dyer from Alberta, Canada. Hubble's version on the right. It's not as pretty, but it's got inner bigness.

You already know the story. Comet Holmes was a boring comet out near the orbit of Jupiter when it flared up on October 23rd. The coma of gas and dust expanded away from the comet, and now it extends to a volume larger than the Sun.

Of course, astronomers scrambled to turn the mighty Hubble Space Telescope to join in on the sky show. The space observatory's Wide Field Planetary Camera 2 monitored the object for several days, capturing images on October 29, 31 and November 4.

The Hubble image reveals the comet's nucleus down to a resolution as small as 54 km (33 miles) across. The image was processed to reveal differences in dust distribution near the nucleus.

Astronomers found that there's twice as much dust along the east-west direction as the north-south direction. This gives the comet a bowtie appearance. Even 12 days after the outburst, when this picture was captured, the nucleus is still surrounded by bright dust.

This isn't the first time that Hubble has viewed Comet Holmes. Luckily, it actually captured an image back in June 15, 1999. Back then, there was no dust around the object, and Hubble couldn't reveal the nucleus. By measuring its brightness, astronomers estimated that Holmes is approximately 3.4 km (2.1 miles) across.

Once Holmes settles down again, astronomers will use Hubble to make another accurate measurement of its brightness. By calculating the difference, astronomers will be able to figure out how much mass it lost during this outburst.

Radical New Steering Thruster Tested


With the shuttle and station in the news these days, it's easy to forget there's a whole other space program in the works: Constellation. Over the next decade, we'll go back to the Moon - this time to stay. Although it's inspired by the Apollo program, each piece of hardware is being updated with the latest technology. This week a radical new type of engine was tested at Northrop Grumman; an engine that could help steer spacecraft in space.

Northrop Grumman, one of the contractors on the NASA Constellation Program, announced this week that they've tested a new rocket called the TR408.

First a little history. The original Apollo program used thrusters powered by fuels that could be stored at room temperature, but they weren't very powerful. Furthermore, they were made with toxic chemicals that could be a risk to astronauts and workers.

The new TR408 engine is a hybrid, which can run on almost any state of oxygen and methane. It could be all gas, for example, stored at room temperature. Or it could be all liquid, similar to the liquid oxygen/hydrogen that powers the space shuttle.

The engine was tested for more that 50 separate tests, and was able to generate a steady-state specific impulse of 340 seconds. Just to give you some context, the Apollo thrusters generated a specific impulse of 290 seconds. The shuttle's liquid hydrogen/oxygen engine gets about 450 seconds.

Although the TR408 doesn't match up to the efficiency of liquid hydrogen/oxygen, it looks like it'll be a great compromise for the unique requirements of space travel.

There are more advantages. The TR408 is a very simple design, consisting of only two propellant valves, and no other moving parts. Less moving parts, means less things that can break. They should also be relatively inexpensive to build.

Northrup Grumman was awarded the contract to develop the engine for NASA 16 months ago, and they're pleased with the progress so far.

Although this engine is designed for low thrust tasks, like steering a spacecraft, more powerful versions are in the works. NASA engineers recently tested a methane/liquid oxygen rocket for 103 seconds, and XCOR Aerospace is working on a version that was tested in a vacuum chamber.

Rosetta Flyby Shows the Earth's Night Side


Right on schedule on November 13th, ESA's Rosetta spacecraft made its 2nd earthly flyby; testing its scientific instruments, and receiving a much needed gravitational assist. About two hours before its flyby, the spacecraft captured this image of the Earth's night side, including Asia, Africa and Europe.

When it captured this image, Rosetta was about 80,000 km (50,000 miles) away from the Earth, above the Indian Ocean. It imaged the planet using its OSIRIS instrument.

You can make out the continents Asia, Africa and Europe by the lighted areas of population centres. With less electricity, Africa has large darkened regions. Australia is down at the lower right-hand side of the image, partly lit by the Sun.

Rosetta's closest approach occurred at 20:57 GMT (3:57 pm EST) at a height of 5,295 km (3,290 miles) above a region of the Pacific Ocean, just off the coast of Chile.

The spacecraft has now completed 3 billion km of its 7.1 billion km journey to reach comet 67/P Churyumov-Gerasimenko. This was the third planetary swing-by for Rosetta and its second swing-by of Earth.

Now on its way out, Rosetta will focus its instruments on the Moon, and the Earth/Moon system. You can expect more cool images, and maybe even one with both the Earth and the Moon in a single frame. Now that would put things into perspective.

Rosetta will be back. It's expected to make its third and finally flyby in November 2009. But not before it makes a visit to the asteroid belt, to study asteroid Steins in September 2008.

Wednesday, November 14, 2007

Gigantic Delta 4-Heavy Blasts Off


On Saturday night, the largest US rocket blasted off, carrying a 2.3 tonne Defense Support Program satellite into orbit. This was the second time a Delta IV-Heavy rocket has ever lifted off. With three core boosters strapped together, it's like three rockets launched at once.

The launch was made even more spectacular because it was held at night. Launched at 0150 GMT Sunday (20:50 EST on Saturday), the 70-metre tall (230 feet) rocket has three separate engines, each of which can generate more than 2,900 kiloNewtons (650,000 pounds) of force. They guzzle a tonne of propellant every second.

On board the rocket was the Defense Support Program 23 spacecraft; the last in a program of Earth observation satellites designed to spot enemy missile launches and nuclear explosions.

Although the Delta IV-Heavy can carry 13 tonnes into a geostationary transfer orbit, it's not a commercial provider - just military and government satellites. Europe's Ariane 5 ECA is the most powerful commercial provider, able to blast off with 10 tonnes.

The Delta IV-Heavy first flew back in 2004. Boeing had originally proposed it as the vehicle that could carry the next wave of space exploration vehicles into orbit. In the end, though, NASA decided to go with the new Ares vehicle for its post-shuttle program.

During that previous test flight, the Heavy encountered a problem with its fuel lines, which caused the engines to go out early, and left the rocket lower than its intended orbit.

Just to put the capabilities of the rocket in perspective, though, the Saturn 5 could put out three times the thrust.



Oops, That Isn't an Asteroid, it's Rosetta


ESA's Rosetta was inbound to make a flyby of the Earth on November 13th? Well, another group of astronomers were watching this "unknown" object, and thought that it was actually an asteroid that was going to be making a close flyby of our planet. The astronomers realized their mistake, but not after an alert was sent out to the astronomical community. Oops.

The alert was sent out by the Minor Planet Center, a clearinghouse of asteroid information organized by the Smithsonian Astrophysical Observatory for the International Astronomical Union.

Astronomers had been tracking the approaching object, designated 2007 VN84. After many observations from astronomers around the world, they calculated that it would pass us by at a distance of 1.89 radii (from the middle of the Earth).

It would have been huge news, but Denis Denisenko from Moscow's Space Research Institute (IKI) realized that its flight path perfectly matched the upcoming Rosetta flyby.

Here's a link to an animation, captured by astronomers in Germany, of Rosetta inbound to the Earth.

And so, just to set the record straight, ESA's Rosetta spacecraft made its flyby on Tuesday, November 13th at 20:57 GMT, passing just 5,301 km above the Pacific Ocean. This has given it the gravitational boost it needs to meet up with Comet Churyumov-Gerasimenko in 2014.



Tuesday, November 13, 2007

Comet Holmes Bigger Than The Sun


Formerly, the Sun was the largest object in the Solar System. Now, comet 17P/Holmes holds that distinction.

Spectacular outbursting comet 17P/Holmes exploded in size and brightness on October 24. It continues to expand and is now the largest single object in the Solar system, being bigger than the Sun (see Figure). The diameter of the tenuous dust atmosphere of the comet was measured at 1.4 million kilometers (0.9 million miles) on 2007 November 9 by Rachel Stevenson, Jan Kleyna and Pedro Lacerda of the University of Hawaii Institute for Astronomy. They used observations from a wide-field camera on the Canada-France-Hawaii Telescope (CFHT), one of the few professional instruments still capable of capturing the whole comet in one image. The present eruption of comet Holmes was first reported on October 24 and has continued at a steady 0.5 km/sec (1100 mph) ever since. The comet is an unprecedented half a million times brighter than before the eruption began. This amazing eruption of the comet is produced by dust ejected from a tiny solid nucleus made of ice and rock, only 3.6 km (roughly 2.2 miles) in diameter.

Caption: (Left) Image of comet Holmes from the 3.6-meter Canada-France-Hawaii telescope on Mauna Kea showing the 1.4 million km diameter coma. The white ''star'' near the center of the coma is in fact the dust-shrouded nucleus. (Right) the Sun and planet Saturn shown at the same scale for comparison. (Sun and Saturn images courtesy of NASA's SOHO and Voyager projects).

The new image also shows the growth of a tail on comet Holmes (the fuzzy region to the lower right in the comet picture), caused by the pressure of sunlight acting on dust grains in the coma. Over the next few weeks and months, the coma and tail are expected to expand even more while the comet will fade as the dust disperses. Comet Holmes showed a double outburst in November 1892 and January 1893. It is not known if the present activity in the comet will follow the pattern from 1892, but continued observations from Mauna Kea are planned to watch for a second outburst. Most comets show small fluctuations in brightness and some have distinct outbursts. The huge event on-going in comet Holmes is unprecedented, however.

The orbit period of comet Holmes is about 6 years, putting it in the class of Jupiter Family Comets whose orbits are strongly influenced by Jupiter. These objects are thought to have spent most of the last 4.5 billion years orbiting the Sun beyond Neptune, in a region known as the Kuiper Belt. Holmes probably was deflected into its present orbit within the last few thousand years and is losing mass as it evaporates in the heat of the Sun. In another few thousand years it is likely either to hit the Sun or a planet, be ejected from the Solar system, or simply die by running out of gas.

Hidden Details of Earth's Atmosphere Revealed By Orbiting Spacecraft


Watching the stars set from the surface of the Earth may be a romantic pastime but when a spacecraft does it from orbit, it can reveal hidden details about a planet’s atmosphere.

The technique is known as stellar occultation. Jean-Loup Bertaux, Service d'Aeronomie du CNRS, France was the first to suggest its use on an ESA mission. It works by watching stars from space, while they drop behind the atmosphere of a planet under investigation, before disappearing from view below the planet’s horizon.

When the stars are shining above the atmosphere, they give off radiation across a wide spread of wavelengths. As the orbit of the spacecraft carries it around the planet, the star appears to sink down, behind the atmosphere of the planet. The atmosphere acts as a filter, blocking out certain wavelengths of the star’s radiation. The key to this technique is that the blocked wavelengths are representative of the molecules and atoms in the planet’s atmosphere.

ESA currently has three spacecraft around three different planets that are using the technique to investigate those atmospheres. Each one is returning unique insights.

Around Earth, ESA’s Envisat mission carries an instrument called GOMOS (Global Ozone Monitoring by Occultation of Stars). As its name suggests, it is designed to study whether the quantity of ozone is increasing now that the use of harmful chemicals has been banned. Since 2002, it has been watching about 400 stars set behind the Earth every day in order to build up a map of the ozone in the Earth’s atmosphere for all latitudes and longitudes.

“It’s still too early to say whether the ozone is recovering or not,” says Bertaux. Nevertheless, as data accumulates, so the instrument is discovering other phenomena that contribute to the amount of ozone in the atmosphere. In January and February of 2004, GOMOS saw a large build up of nitrogen dioxide at an altitude of 65 km.

Nitrogen dioxide is an important gas to trace in the atmosphere because it can destroy ozone. Over the next two months, GOMOS watched as the layer sank to 45 km, clearly destroying ozone as it descended, providing scientists with another piece in the ozone puzzle.

A simplified stellar occultation instrument is onboard ESA’s Mars Express. Since the spacecraft arrived at the Red Planet in 2003, SPICAM (Spectroscopy for Investigation of Characteristics of the Atmosphere of Mars) has observed more than 1000 stellar occultations. This work provides the most detailed description yet of Mars’s upper atmosphere, and reveals persistent haze layers.

Apart from delivering pure science, the data provides practical benefits for future exploration missions. “Atmospheric profiles of Mars are important for designing parachutes for landing craft,” says Bertaux.

The latest addition to this family of instruments is SPICAV (Spectroscopy for Investigation of Characteristics of the Atmosphere of Venus) on Venus Express. Venus has a different atmosphere again from Earth or Mars. It is much denser and SPICAV is revealing the temperature and density profiles of the atmosphere to waiting scientists on Earth, who expect to publish their results soon.

“I think the stellar occultation technique is now ‘combat proven’ and should be useful for further long-term studies,” says Bertaux.

The article reflects results from two publications. 'Stellar Occultations at UV wavelengths by the SPICAM instrument: Retrieval and analysis of Martian haze profile' by F. Montmessin, J.L. Bertaux and P. Rannou was published in the Journal of Geophysical Research in 2006.

The second article 'Large increase of NO2 in the north polar mesosphere in January-February 2004: Evidence of a dynamical origin from GOMOS/Envisat and SABER/TIMED data' by A. Hauchecorne, J.L. Bertaux, F. Dalaudier, J.M. Russell III; M.G. Mlynczak, E. Kyrola, and D. Fussen was published in the Geophysical Research Letters on 16 February 2007.

Antique fridge could keep Venus rover cool


A high-tech refrigeration system could keep a rover functioning for weeks on the searingly hot surface of Venus, say NASA researchers. A long-lived Venus rover could help scientists understand why Venus, with its runaway greenhouse effect, has become so different from Earth.

The surface of Venus broils at a temperature of about 450 °C – hot enough to melt lead. Several probes in the Soviet Venera and Vega series, as well as a NASA Pioneer Venus probe, landed on Venus and returned data from the surface in the 1970s and early 1980s. But they all expired in less than 2 hours because of the tremendous heat.

Now, two NASA researchers have designed a refrigeration system that might be able to keep a robotic rover going for as long as 50 Earth days. The work was carried out by Geoffrey Landis and Kenneth Mellott of NASA's Glenn Research Center in Cleveland, Ohio, US.

The main concern is keeping the electronics cool. The NASA pair plan to do this by packing the electronics in a ceramic-based insulator and placing it inside a metal sphere about the size of a grapefruit.

Stirling cooler

Heat would then be pumped out of the sphere using a Stirling cooler, which works by compressing and then expanding a gas with a piston. When the gas expands, it cools down, absorbing heat from the electronics chamber. Then, as the gas is compressed and its temperature rises, the heat is allowed to dissipate in the atmosphere via a radiator.

Stirling coolers were invented in 1816 by Reverend Robert Stirling, a Scottish clergyman, but were largely ignored until the mid 20th century, when their impressive energy efficiency became better known.

They are already used on Earth to cool equipment in deep shafts drilled in rock for oil exploration, and are being developed for use in energy-saving home refrigerators. Landis and Mellott have now designed one suitable for use in the incredibly hot environment of Venus.

But to dissipate heat, the radiator has to be hotter than the surrounding atmosphere, so the new design can reach 500 °C. The cool end of the Stirling engine would keep the rover's innards at a relatively chilly 200 °C, which should allow commercially available electronics to operate well.

The researchers say the power to run the Stirling cooler, about 240 watts, would be provided by on-board plutonium batteries, which generate power from the heat of radioactive decay.

"The next step is probably going to be trying to build some prototypes and just demonstrate that what we are proposing is something that's going to work," Landis.

Challenging mission

NASA has not committed to a Venus rover mission, but Landis notes that a 2003 National Academies of Science study recommended that high priority be given to a robot mission to investigate the Venusian surface. Landis thinks a Venus rover could become a reality within a decade or so.

But such a mission is not without its challenges, says Venus researcher Mark Bullock of the Southwest Research Institute in Boulder, Colorado, US. "I think that a long-lived rover on Venus is a very, very difficult mission".

However, he thinks the Stirling cooler is a promising approach: "Active cooling is essential, and the Stirling cycle cooler with a radioisotope power source is probably the very best way to do it."

Putting a long-lived rover on the surface of Venus could revolutionise our understanding of the planet, helping to answer such questions as why Venus ended up so different from Earth, he says. Many scientists suspect Venus was much cooler in the past, and was perhaps even covered with oceans of liquid water where conditions could have been friendly to life.

Monday, November 12, 2007

Nearby Barred Spiral Galaxy Shows Off Its Warped Disc


Known until now as a simple number in a catalogue, NGC 134, the 'Island in the Universe' is replete with remarkable attributes, and the VLT has clapped its eyes on them. Just like our own Galaxy, NGC 134 is a barred spiral with its spiral arms loosely wrapped around a bright, bar-shaped central region.

One feature that stands out is its warped disc. While a galaxy's disc is often pictured as a flat structure of gas and stars surrounding the galaxy's centre, a warped disc is a structure that, when viewed sideways, resembles a bent record album left out too long in the burning Sun.

Warps are actually not atypical. More than half of the spiral galaxies do show warps one way or another, and our own Milky Way also has a small warp.

Many theories exist to explain warps. One possibility is that warps are the aftermath of interactions or collisions between galaxies. These can also produce tails of material being pulled out from the galaxy. The VLT image reveals that NGC 134 also appears to have a tail of gas stripped from the top edge of the disc.

So did NGC 134 have a striking encounter with another galaxy in the past? Or is some other galaxy out there exerting a gravitational pull on it? This is a riddle astronomers need to solve.

The superb VLT image also shows that the galaxy has its fair share of ionised hydrogen regions (HII regions) lounging along its spiral arms. Seen in the image as red features, these are glowing clouds of hot gas in which stars are forming. The galaxy also shows prominent dark lanes of dust across the disc, obscuring part of the galaxy's starlight.

Studying galaxies like NGC 134 is an excellent way to learn more about our own Galaxy.

NGC 134 was discovered by Sir John Herschel at the Cape of Good Hope and is located in the Sculptor southern constellation. The galaxy is located about 60 million light-years away - when the light that was captured by the VLT originally left the galaxy, a dramatic episode of mass extinction had led to the disappearance of dinosaurs on Earth, paving the way for the appearance of mammals and later specifically of humans, who have built unique high-tech installations in the Atacama desert to satisfy their curiosity about the workings of the Universe. Still, NGC 134 is not very far away, by cosmological standards. It is the dominant member of a small group of galaxies that belongs to the Virgo or Local Supercluster and is one of the 200 brightest galaxies in our skies.

During his visit to ESO's Very Large Telescope at Paranal, the European Commissioner for Science and Research, Janez Poto─Źnik, participated in an observing sequence and took images of this beautiful spiral galaxy.

Sunday, November 11, 2007

Spitzer Sees a Baby Star Blowing Bubbles


A new image released from NASA's Spitzer Space Telescope shows a baby star blowing bubbles, just like, I guess, a kid with bubblegum. But let's see your kid hurl out material hundreds of kilometres a second across light-years of space. Those are some big bubbles.

The infant star is known as HH 46/47, and it's located about 1,140 light-years from Earth. The star itself is that bright white spot at the middle of the image.

Surrounding the star are two bubbles of material extending out in opposite directions. These bubbles are formed when powerful jets of gas collide with the cloud of gas and dust surrounding the star. The red specks at each end signify hot sulfur and iron gas, where the jets are colliding head on into the gas and dust material.

Astronomers think that young stars accumulate material by gravitationally pulling in gas and dust. This process ends when the star gets large enough to create these jets. Any further material is just blown away into space.

Producing this image was a bit of a technical achievement. The researchers at NASA's JPL developed an advanced image-processing technique for Spitzer data called Hi-Res deconvolution. The process reduces blurring, and makes the image sharper and clearer. With this technique, astronomers were able to make out the details of HH 46/47, and its surrounding bubbles.



Black Holes Linked to Cosmic Rays


You know that big list of unsolved mysteries in astronomy? Well, you can remove, "what causes the highest energy cosmic rays?" Thanks to new research using the Pierre Auger Cosmic Ray Observatory in South America, the answer appears to be: supermassive black holes.

High energy cosmic rays are actually particles - protons mostly - accelerated to tremendous velocities. When they crash into the Earth's atmosphere, they explode in a spray of energy and sub-particles that can be detected here on the surface. Fortunately our atmosphere protects us from damage, but out in space, they're a real threat.

Just a single particle can have the same energy as fast moving tennis ball.

Astronomers have been wondering for years how particles can get boosted to such high energy levels. A massive team of 370 researchers from 17 countries have been working on the answer using the newly developed Pierre Auger Cosmic Ray Observatory, nestled in the mountains of South America.

The observatory is actually an array of detectors spread out over a 3,000 km2 area. As the cosmic rays collide with the atmosphere, the resulting spray of particles are caught by the detectors, which house large tanks of water. The detectors are so sensitive, they can detect a different in timing, which allow astronomers to triangulate the direction the cosmic ray came from. The particles are flung with such energy that they point back to their galaxies, like bullets coming from a gun.

Before the Pierre Auger observatory, cosmic ray detections were rare. Astronomers just didn't have enough data to know where they were coming from. But over the last 3 years, the observatory has recorded a million cosmic rays, including 80 of the highest energy.

Astronomers now know that cosmic rays don't come from all regions of the sky, but they're shot out from actively feeding supermassive black holes.

The exact process that creates the cosmic rays isn't fully understood, but astronomers think that the environment around an active supermassive black hole is ferocious, to say the least. Powerful magnetic fields are generated, which can act like natural particle accelerators, pushing protons to energy levels much higher than anything physicists could recreate with our technology.

Rosetta Is Returning to Earth for Another Flyby


Mark your calendars for November 13th, 2007. That's the day ESA's Rosetta spacecraft will be making a close encounter with Earth on its way to Comet 67/P Churyumov-Gerasimenko. What's going on? The comet's out there guys, why is Rosetta back home? Well, it's all about speed.

Launching spacecraft is an energy intensive business. You can only get a spacecraft going so fast when it launches directly from Earth. But using a technique called gravity assist, spacecraft can use the gravity of a planet - such as the Earth - to get a speed boost. Most of the robotic explorers do it.

In order for Rosetta to make its encounter with Comet 67/P Churyumov-Gerasimenko in 2014, it needs to be going much faster. It already got a gravity assist from Earth back in March 4, 2005, and another with Mars on February 25, 2007. Now its time for a third on November 13. We won't be done with Rosetta yet, either. The spacecraft is due to make a 4th and final flyby on November 13, 2009.

Before it returns for the 4th flyby, Rosetta will swing out across the asteroid belt and observe asteroid Lutetia, testing out its scientific equipment.

Finally, in 2014, Rosetta will reach Comet 67/P Churyumov-Gerasimenko and begin some serious investigations; even landing a probe down on its surface.

Thursday, November 8, 2007

Supermassive Black Holes Produce Powerful Galaxy-shaping Winds


Supermassive black holes can produce powerful winds that shape a galaxy and determine their own growth, confirms a group of scientists from Rochester Institute of Technology.

The RIT team has, for the first time, observed the vertical launch of rotating winds from glowing disks of gas, known as accretion disks, surrounding supermassive black holes in the centers of galaxies.

Gas flowing into a supermassive black hole first accumulates in a rapidly spinning accretion disk, which forms the engine of a quasar, a type of active galactic nucleus found in some galaxies and an extremely powerful source of radiation.

“Gas flowing in from the galaxy ‘fuels’ the quasar,” says Andrew Robinson, associate professor of physics at RIT and an author of the study. “Gas flowing out from the quasar regulates black hole growth and galaxy formation.”

The RIT team, consisting of Stuart Young, David Axon and Robinson, together with colleagues James Hough and James Smith from the University of Hertfordshire in England, studied the winds of gas coming off the quasar PG 1700+518, located in a galaxy at a distance of approximately 3 billion light-years from Earth. Robinson and Smith obtained the data using the William Herschel Telescope on the Canary Islands.

Previous studies have pointed to the critical role winds play in the early or active phase of a galaxy, when a growing supermassive black hole draws in gas from the surrounding cloud and shines luminously—brighter than all of the stars in a galaxy.

“It has long been thought that such winds are launched from the accretion disk but, until now, this idea has been based on purely theoretical arguments,” says David Axon, professor and head of the physics department at RIT.

The RIT team’s study of PG 1700+518 shows that gas is both moving vertically away from the disk and also rotating at a speed similar to the disk’s rotation speed—direct observational confirmation that the disk is launching a wind. The study also helps to resolve the long-standing mystery of how the accretion disk rids itself of angular momentum—a property associated with rotational motion that inhibits the inward flow of gas towards the central black hole just as it keeps the Earth in orbit around the sun.

“If it wasn’t removed, angular momentum would actually completely stop the accretion and turn off the quasar,” says Young, a post-doctoral fellow at RIT, formerly of the University of Hertfordshire, and the lead author of the paper “The Rotating Wind of the Quasar PG 1700+518.” “Our work suggests that the disk removes some of its excess angular momentum by launching a wind, so allowing accretion to happen in the first place to produce the quasar and allow the black hole to grow.”

Quasar accretion disks are too small to be imaged directly. The RIT team confirmed theories about quasar winds by using polarimetry, a technique that measures the polarization of the light from the quasar, a property that can arise when light, or electromagnetic radiation, is scattered or reflected. This technique gives scientists ways to analyze astronomical sources from different perspectives.

“We can’t actually see the accretion disk,” adds Robinson. “We can see its radiation, but we can’t actually see its structure. In a picture, a quasar looks just like a star, so it’s proven very difficult to confirm these theories by observation.”

He continues: “In quasars, like PG1700+518, we believe that light emitted by the accretion disk becomes polarized because it is scattered by electrons in the wind; the process is similar to scattering of sunlight by molecules in Earth’s atmosphere, which makes the sky appear blue.”

Analyzing changes in the polarization of the light with wavelength, or the property that determines color, can reveal information about the internal structure of a source and the motions of the emitting and scattering gas.

During the last 20 years, studying the polarized light from active galactic nuclei has allowed scientists to make sense of a confusing variety of different types of active galaxy.

“When you look at an active galactic nucleus from above you see one kind of active galaxy,” Robinson says. “When you look at it from the side you see another kind. Polarimetry makes clear that they are the same. Scientists used to think there were different types of active galaxies. Now we know they are only different because we are looking at them from different angles.”

During the next phase of their research, the RIT scientists will analyze the polarization properties of scattered light from many more objects to learn if powerful disk winds are launched only in a relatively short-lived phase, when the black hole is growing rapidly, or if they are launched only by quasars, which have the most massive black holes, or by all active galactic nuclei.

“The polarization process makes this very interesting because you get this discrimination between angles, and you get different viewpoints,” Robinson says. “And so the observed properties of the nucleus depend on angle, whether or not the direct view is obscured.”

Wednesday, November 7, 2007

Big Chunk Of The Universe Is Missing -- Again


Not only has a large chunk of the universe thought to have been found in 2002 apparently gone missing again but it is taking some friends with it, according to new research at The University of Alabama in Huntsville (UAH). The new calculations might leave the mass of the universe as much as ten to 20 percent lighter than previously calculated.

The same UAH group that found what was theorized to be a significant fraction of the "missing mass" that binds together the universe has discovered that some x-rays thought to come from intergalactic clouds of "warm" gas are instead probably caused by lightweight electrons.

If the source of so much x-ray energy is tiny electrons instead of hefty atoms, it is as if billions of lights thought to come from billions of aircraft carriers were found instead to come from billions of extremely bright fireflies.

"This means the mass of these x-ray emitting clouds is much less than we initially thought it was," said Dr. Max Bonamente, an assistant professor inUAH's Physics Department. "A significant portion of what we thought was missing mass turns out to be these 'relativistic' electrons."Traveling at almost the speed of light (and therefore "relativistic"), these feather weight electrons collide with photons from the cosmic microwave background. Energy from the collisions converts the photons from low-energy microwaves to high-energy x-rays.

"The discovery was made while trying to analyze the makeup of warm, x-ray emitting gas at the center of galaxy clusters - the largest cosmological structures in the universe. In 2002 the UAH team reported finding large amounts of extra "soft" (relatively low-energy) x-rays coming from the vast space in the middle of galaxy clusters. This was in addition to previously-discovered "hot" gas in that space, which emits higher energy"hard" x-rays.

Although the soft x-ray-emitting atoms were thought to be spread thinly through space (less than one atom per cubit meter), they would have filled billions of billions of cubic light years. Their cumulative mass was thought to account for as much as ten percent of the mass and gravity needed to hold together galaxies, galaxy clusters and perhaps the universe itself.

When Bonamente and his associates looked at data gathered by several satellite instruments, including the Chandra X-ray Observatory, from a galaxy cluster in the southern sky, however, they found that energy from those additional soft x-rays doesn't look like it should."We have never been able to detect spectral emission lines associated with those detections," he explained. "If this 'bump' in the data were due to cooler gas, it would have emission lines.

"The best, most logical explanation seems to be that a large fraction of the energy comes from electrons smashing into photons instead of from warm atoms and ions, which would have recognizable spectral emission lines.Finding these electrons, however, is like finding "the tip of the iceberg,"said Bonamente, because they would not be limited to emitting only the soft x-ray signal. The signal from these electrons would also make up part of the previously observed harder X-rays, which would reduce the amount of mass thought to make up the hot gas at the center of galaxy clusters.

To further complicate the issue, the energy from these electrons might also"puff up" the cluster. Previously, astrophysicists used the energy coming from inside these clusters to calculate how much mass is needed to reach the equilibrium seen there; too much mass and the cloud would collapse; too little and the hot gas cloud would expand.Since the energy coming from these hot clouds can be accurately measured, it was thought the mass could be calculated with reasonable confidence - for astrophysics.Instead, says Bonamente, if a significant portion of the total x-ray energy comes from fast electrons, "that could trick us into thinking there is more gas than is actually there.""It means we need to revise how we calculate both the gas mass and the total mass," he said. "We have to follow the evidence and, if that leads us to confusion, well that's OK."If part of the hard x-ray energy comes from electrons and photons, it might also shift what we think is the mix of elements in the universe.

Outside of the excess soft x-rays, the x-ray energy coming from galaxy clusters has emission lines which are especially prominent around iron and other metals.Non-thermal x-rays from electrons colliding with photons might mask those emission lines, like thick snow can mask the height of fence posts."This is also telling us there is fractionally more iron and other metals than we previously thought," said Bonamente. "Less mass but more metals."

Space Mission Xeus Probes Origins Of The Universe


A new mission seeks to study the origins of the universe. Professor Martin Turner of the Department of Physics and Astronomy is Co-Principal Investigator on XEUS - a next-generation X-ray space observatory.

XEUS, which stands for X-ray Evolving Universe Spectroscopy, aims to study the fundamental laws of the Universe. With unprecedented sensitivity to the hot, million-degree universe, XEUS will explore key areas of contemporary astrophysics: growth of supermassive black holes, cosmic feedback and galaxy evolution, evolution of large-scale structures, extreme gravity and matter under extreme conditions, the dynamical evolution of cosmic plasmas and cosmic chemistry.

Professor Turner is also Chair of the XEUS International Steering committee. He said: “XEUS is an X-ray observatory 30-50 times more sensitive than XMM-Newton, which will be placed 1.5 million km from Earth, beyond the Moon, at the second Lagrangian point, a quiet stable location where the instruments can observe the universe undisturbed.

“Because it is so large, the observatory has two spacecraft. The five-metre diameter X-ray lens is in one, and the instruments in another. The two spacecraft fly together, 35 metres apart, to keep the instruments at the focus of the lens.

“XEUS has been selected for study by ESA as part of its Cosmic Vision programme. If the study outcome is successful it will be launched on Ariane 5 from Kourou in 2018.

"We have been developing the XEUS concept for an advanced X-ray observatory, for many years. This acceptance by ESA is a major step forward for X-ray astronomers all over the world."

"The million degree universe, where gravity is the main source of energy, is the finest physics laboratory we have. XEUS will help us find out about the behaviour of matter under extreme conditions of temperature, pressure, and gravity. It will also let us study the influence of black holes on the formation of galaxies and stars; and ultimately planets and ourselves."

Dr Richard Willingale, of the University of Leicester and chairman of the XEUS telescope working group said.

“XEUS will use new lightweight silicon optics to make the lens, the same material used to make silicon chips; one of the instruments has sensors cooled to within a tiny fraction of absolute zero to study the chemistry and physics of matter surrounding black holes.”

Various international Space Agencies have expressed interest in cooperation in XEUS and discussions will start by the end of the year to ensure the earliest involvement in study work.

All the candidate missions are now competing in an assessment cycle which ends in 2011. Before the end of the cycle, there will be an important selection foreseen in 2009. At the end of this process, two missions will be proposed for implementation to ESA's Science Programme Committee, with launches planned for 2017 and 2018 respectively.

The selected missions fit well within the themes of ESA's Cosmic Vision 2015-2025 plan. The themes range from the conditions for life and planetary formation, to the origin and formation of the Solar System, the fundamental laws of our cosmos and the origin, structure and evolution of the Universe.

“The maturity of most of the proposals received demonstrates the excellence of the scientific community in Europe. This made the task of the SSAC very difficult but we believe that the set of selected missions will shape the future of European space science,” said Tilman Spohn, chairperson of the SSAC (German Aerospace Center, Berlin). “The next decade will indeed be very exciting for the scientific exploration of space.”

According to the chair of the Astronomy Working Group (AWG), Tommaso Maccacaro, (INAF – Osservatorio Astronomico di Brera) “The chosen candidates for astronomy missions show very promising and broad scientific return and have received excellent recommendations also from external referees.”

“Technical feasibility and potential for successful cooperation with other agencies are two factors which are clearly evident in the Solar System missions that have been chosen,” added Nick Thomas at the Physikalisches Institut, Universit├Ąt Bern, chair of the Solar System Working Group.

In 2004, Professor Turner was honoured with a CBE for services to X-ray astronomy. Paying tribute to his colleague, Professor George Fraser, Director of the Space Research Centre, said at the time: “The award of a CBE to Martin Turner is very well-deserved recognition of a tremendous contribution to the field of X-ray Astronomy in a career of over thirty years here at Leicester. Martin has, perhaps uniquely, led the development of three major instruments in the field -launched on the EXOSAT (1983), Ginga (1987) and XMM-Newton (1999) –of which he is Principal Investigator- satellites. The last of these - the EPIC camera -has now performed flawlessly in orbit for four years. Martin, nothing daunted, is also heavily involved in the initial design stages of the successor to XMM, a giant European observatory called XEUS.”

Fifth Planet Found Orbiting 55 Cancri


Our Solar System has 8 planets, but another, 55 Cancri, is catching up fast. Astronomers today announced the discovery of a 5th planet in the system, located 41 light-years away. This newly discovered planet weighs in with 45 times the mass of the Earth, and might look similar to Saturn in composition and appearance. But the news gets better, it's in the star's habitable zone, and could have water-covered moons.

The discovery of a 5th planet around 55 Cancri was made by astronomers from UC Berkeley, and several other collaborating universities, with funding from NASA and the National Science Foundation. Their research will appear in an upcoming issue of the Astrophysical Journal.

Astronomers used the radial velocity technique to find the planets. This is where the velocity of the star is carefully measured. Periodic changes in this velocity mean that a large planet's gravity is yanking the star back and forth. In this case, the discovery was even more difficult, because there were already known planets in the system, polluting the data.

"It is amazing to see our ability to detect extrasolar planets growing," said Alan Stern, associate administrator for the Science Mission Directorate at NASA Headquarters, Washington. "We are finding solar systems with a richness of planets and a variety of planetary types comparable to our own."

Perhaps the coolest part of this whole discovery: the planet orbits its parent star once every 260 days. This places it within its star's habitability zone, where liquid water can be present. It's a little closer than our Earth is to the Sun, but its star is also a little fainter, so it all evens out.

Obviously, this rules out the planet itself, but it could have a collection of moons, just like Saturn. Instead of Saturn's icy moons, this 5th planet of 55 Cancri could have ocean moons.

Finding this planet was an enormous challenge. The discoverers have been making observations of 55 Cancri for 18 years, before the first extra solar planets were ever found. They had to make more than 320 velocity measurements to disentangle the 5 planets from the data.

First Look at the Orion Crew Module


The Constellation program will continue the US human spaceflight efforts, eventually bringing people back to the Moon. As part of the program, workers at NASA unveiled a mockup of the Orion crew module.

The lifesize Orion crew module was build by engineers at NASA's Dryden Flight Research Center's Fabrication Branch. No, this aluminum mockup won't actually be flying. It won't even be used for aerodynamic testing. It's just going to help engineers figure out how to cram everything in.

As the engineers are developing the various avionics systems, instrumentation, wire harness routing, etc, they'll want a life-size mockup of the module to test how things fit together. Eventually, you can imagine future astronauts crawling inside, and giving engineers their feedback on the placement of the instrumentation, the feel of the controls, and cushiness of the seats.

This mockup will help engineers until the first abort flight test vehicle, called "Boilerplate 1" arrives for testing. This next testing vehicle is a flying simulator that will mimic the flight characteristics of the actual vehicle. Boilerplate 1 will have the same mass, dimensions, and aerodynamic properties of the Orion capsule, so it can be tested in wind tunnels and atop rockets.

NASA is planning two pad abort, and four ascent tests of the launch abort system as early as 2008, and continuing on through 2011.

Tuesday, November 6, 2007

SpaceDev Completes Milestone Under NASA Space Act Agreement


SpaceDev recently completed its first milestone under the Space Act Agreement that it signed with NASA in June 2007. This significant first milestone is to define the outer mold line (OML) of the SpaceDev Dream Chaser space vehicle. The SpaceDev team generated a surface model that will be used for future analysis, subscale flight test modeling, and full scale tooling of the Dream Chaser flight vehicle. The Dream Chaser OML surface model was derived from digitized scans of the original NASA Langley wind-tunnel tested models, which are currently on loan to SpaceDev.

SpaceDev entered into the Space Act Agreement with NASA's Johnson Space Center to facilitate its development of reliable, safe and affordable transportation of passengers and cargo to and from Earth orbit. As part of the agreement, NASA is providing support regarding commercial vehicle requirements for rendezvous and docking with the ISS as well as ongoing regularly scheduled technical exchange.

"The completion of this initial milestone demonstrates the value of the NASA Space Act Agreement program and how well the SpaceDev and NASA teams are working together to forward the SpaceDev Dream Chaser space system," said Mark N. Sirangelo, SpaceDev's Chairman and Chief Executive Officer. Mr. Sirangelo continued, "SpaceDev is proud to have completed a significant technical milestone and we are proceeding forward on schedule with our program."

The SpaceDev Dream Chaser space vehicle is a derivative of the HL-20 Launch System developed by NASA Langley. The vehicle has on-board propulsion utilizing SpaceDev's patented hybrid motor technology. This unique space transportation system is designed to effectively, reliably and safely carry crew/passengers and cargo in both the suborbital and orbital flight regimes. The SpaceDev Dream Chaser space vehicle can be adapted to various mission configurations including carrying up to six passengers, a combination of passengers and cargo, or a maximized cargo configuration. It is a piloted space solution which launches vertically and lands horizontally on conventional runways. Initial flight demonstrations are scheduled in 2009.

Does Russia Have A Nuclear Engine Advantage


Nuclear rocket engines for manned missions to Mars were actively developed both in the Soviet Union and the United States back in 1960-1970, but the work was stopped before the projects got off the ground.

Plasma and ionic electric jet engines are even more economical and "swift." In them a stream of charged particles is whisked to high velocities by means of an electromagnetic field, almost as in a charged particle accelerator.

Another factor increasing their thrust is the capacity of the equipment creating the field and speeding up the particles.

Russia's experience in developing and operating power reactors in space is unique. From 1970-1988, Russia launched a total of 32 spacecraft with nuclear propulsion units and thermo-electric converters of 3 kilowatts and 5 kilowatts capacity.

Most of these vehicles performed reconnaissance operations and remained in orbit in an activated state for several months at a time.

By comparison, America had only one such craft, with a SNAP 10A nuclear reactor and a 0.5 kW thermo-electric power converter, which was launched in 1965. It did not survive long, lasting a mere 43 days and is now part of the space junk orbiting Earth.

Then the efforts became pure research and did not resume until 2002.

Russia is also an expert at making the so-called stationary plasma engines, which have a thrust one order of magnitude greater than the traditional chemical ones. Their first space tests were carried out in 1972 on the Russian Meteor weather satellite, and the regular operation of serially made vehicles began in 1982 on geostationary satellites to correct their orbits.

At present, practically all countries, including the leading space powers, are making active use of various types of Russian-designed electric jet engines. The power of these engines is such that they can adjust the orbit both in longitude and inclination.

Additionally, they can make inter-orbital jumps along energetically optimal multi-revolution trajectories. For example, they can move from a low orbit to a geostationary one and they also serve as a vehicle for interplanetary travel.

In preparing the manned expedition to Mars, the developers considered many options: liquid rocket engines burning oxygen and hydrogen; nuclear rocket engines with liquid hydrogen as a working agent; and a nuclear and a solar installation to power electric jet engines.

For the core equipment they selected the solar-powered unit with thin-film elements based on amorphous silicon.

As a prospective alternative, consideration is also being given to a nuclear power unit as it is developed to reach an operating stage. The main problem in using such units is nuclear and radiation safety during every stage of operation, including emergencies, which requires further research.

Preoccupied with the nuts and bolts of the interplanetary ship and its propulsion, people tend to forget about many other problems, including physiological and psychological ones.

These and other problems must be addressed before humans set out on an interplanetary journey, but that is the subject for a separate discussion.

Chang'e-1 Enters Lunar Orbit


Chinese space officials announced that their Chang'e-1 spacecraft entered lunar orbit on Monday, completing a new milestone in the country's goals of space exploration. The spacecraft is scheduled to begin scanning the lunar surface on Wednesday, but first, it has to complete two additional braking maneuvers.

Mission controllers gave the command at 11:15 local time from the Beijing Aerospace Control Center (BACC) for Chang'e-1 to make its braking maneuver - when it was 300 km from the Moon. It completed the maneuver 22 minutes later, entering a true circumlunar orbit.

This braking maneuver was critical. If it braked too early, the probe wouldn't have been captured by the Moon's gravity, and it would have drifted off into space. If it braked too late, it would have just crashed onto the lunar surface.


The spacecraft's speed was slowed from 2.3 km/second to 1.9 km/second. It's now traveling in a 12-hour elliptical orbit around the Moon, getting as close as 200 km above the surface, and then swinging out to 8,600 km.

Two more braking maneuvers are planned to lower its orbit; one on November 6th, and another on the 7th. When it's all said and done, Chang'e-1 will be going a mere 1.59 km/second, in a 127-minute orbit. It will then begin its science operations.

If all goes well, Chang'e-1 will provide detailed images and data on the lunar surface. China has announced their plans to send a robotic lander to the Moon by 2012 years, and humans within 15 years.

It should remain in lunar orbit for about a year.



Monday, November 5, 2007

Spirit To Head North For The Winter


With Martian winter approaching, the science and engineering teams have been hard pressed to select a site where Spirit can spend the winter. After previously narrowing the list of candidates to two sites, Spirit's handlers decided to send the rover to the northern edge of the elevated plateau known as "Home Plate," which Spirit has been exploring for many months now.

Previously considered sites included "von Braun," "South Promontory," "Batter's Box" ("West Knoll"), and "North Home Plate." The decision means the rover will move farther away from tantalizing, new terrain to the south, but maximizes the rover's chances of surviving another winter given the excessive coating of dust on the solar arrays.

As Project Manager John Callas announced in an e-mail, "the principal discriminator was the achievable slope at each site. The north side of 'Home Plate' offers slopes of 25 degrees of northerly tilt, while 'South Promontory' offers 20 degrees of northerly tilt. That difference is about 10 watt-hours per sol, which can mean the difference between surviving and not surviving the cold, dark winter."

Meanwhile, Spirit remains healthy and all subsystems are nominal. Energy has been averaging 355 watt-hours (100 watt-hours is the amount of electricity needed to light one 100-watt bulb for one hour) and atmospheric dust measurements (Tau) have been steady at about 0.63.

Plans called for Spirit to head in a northerly direction, toward an area known as "Site 5" on top of Home Plate, starting on sol 1362 (Nov. 2, 2007) . Once there, Spirit may investigate some targets with instruments on the robotic arm before continuing to the north end of Home Plate.

Meanwhile, engineers working on the rover's miniature thermal emission spectrometer have determined that degradation in performance of the spectrometer on both Spirit and its twin, Opportunity, is the result of dust deposition on the scan mirror or in the panoramic camera mast assembly. They have decided not to use the instrument on Opportunity and to use it only for high-priority targets and weekly atmospheric measurements on Spirit while they try to develop strategies for removing the dust.

In addition, tests run on sols 1355, 1358, and 1360 (Oct. 25, Oct. 29, and Oct. 31) determined that the grind motor on Spirit's rock abrasion tool failed on sol 1341 (Oct. 11, 2007) , as it did previously on Opportunity on sol 1045 (Jan. 1, 2007). However, because the rover's handlers have devised an alternate technique for grinding and brushing that takes two Martian days, they are still able to use the brushes on both rock abrasion tools.

Sol-by-sol summary

In addition to receiving morning instructions directly from Earth via the high-gain antenna, sending evening data to Earth at UHF frequencies via the Odyssey orbiter, measuring atmospheric dust levels with the panoramic camera, and surveying the sky and ground with the miniature thermal emission spectrometer, Spirit completed the following activities:

Sol 1355 (Oct. 25, 2007): Spirit unstowed the robotic arm, conducted imaging diagnostics of the rock abrasion tool, and took microscopic images of the capture magnet. The rover placed the alpha-particle X-ray spectrometer on the capture magnet, took panoramic camera images of the rover deck, and transmitted data overnight via the Odyssey orbiter. Spirit monitored dust on the panoramic camera mast assembly, surveyed the horizon with the panoramic camera, acquired a mosaic of images with the navigation camera, and acquired movie frames in search of dust devils with the navigation camera.

Sol 1356: Spirit acquired panoramic camera images of the rover deck and of rock targets nicknamed "Grays Peak," "Elk," and "San Juan." The rover acquired 6 hours worth of data with the alpha-particle X-ray spectrometer and took thumbnail images of the sky with the panoramic camera.

Sol 1357: Spirit used the navigation camera to survey the surface darkened by the rover's shadow. The rover acquired full-color images of its tracks using all 13 filters of the panoramic camera. Spirit acquired another 6 hours of data with the alpha-particle X-ray spectrometer and took spot images of the sky with the panoramic camera.

Sol 1358: Spirit took images of the filter magnet with the microscopic imager, performed diagnostic tests on the rock abrasion tool, and used the panoramic camera to take images of the rover deck and survey the horizon.

Sol 1359: Spirit turned in place for communications relays and performed a "get quick fine attitude" to check for changes in the inertial measurement unit to determine the rover's precise location. Spirit acquired post-drive images with both the navigation and panoramic cameras. In the morning, the rover completed a systematic ground survey with the panoramic camera.

Sol 1360: Spirit unstowed the robotic arm, performed diagnostic tests of the rock abrasion tool, and acquired a mosaic of microscopic images of a soil target known as "Pumpkin Pie" before placing the alpha-particle X-ray spectrometer on the target. Spirit acquired full-color images, using all 13 filters of the panoramic camera, of another soil target known as "Candy Corn." The rover collected data from Pumpkin Pie with the alpha-particle X-ray spectrometer and in the morning, scanned the sky for clouds with the navigation camera. Spirit also surveyed the horizon with the panoramic camera and acquired movie frames in search of dust devils with the navigation camera.

Sol 1361: Spirit stowed the robotic arm in preparation for the next day's drive and took full-color images, using all 13 filters of the panoramic camera, of Elk and San Juan. The rover acquired a mosaic of images with the navigation camera as part of a 360-degree panorama for drive planning. Spirit surveyed the sky at both low sun and high sun with the panoramic camera.

Sol 1362 (Nov. 2, 2007): Plans called for Spirit to drive toward Site 5, acquire full-color, mid-drive images of Pumpkin Pie with all 13 filters of the panoramic camera, and acquire post-drive images with both the navigation and panoramic cameras. The following morning, Spirit was to complete a survey of rock clasts with the panoramic camera and scan the sky for clouds with the navigation camera.

Odometry:

As of sol 1359 (Oct. 30, 2007), Spirit's total odometry was 7,339.70 meters (4.56 miles).

Mars Express Probes The Red Planet's Most Unusual Deposits


The radar system on ESA's Mars Express has uncovered new details about some of the most mysterious deposits on Mars: The Medusae Fossae Formation. It has given the first direct measurement of the depth and electrical properties of these materials, providing new clues about their origin.

The Medusae Fossae Formation (MFF) are unique deposits on Mars. They are also an enigma. Found near the equator, along the divide between the highlands and lowlands, they may represent some of the youngest deposits on the surface of the planet. This is inferred from the marked lack of impact craters dotting this terrain, unlike on older terrain. Mars Express has been collecting data from this region using its Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS). Between March 2006 and April 2007, Mars Express orbited the region many times, taking radar soundings as it went.

For the first time, these radar soundings revealed the depth of the MFF layers, because of the time it took for the radar beam to pass through the top layers and bounce off the solid rock beneath. "We didn't know just how thick the MFF deposits really were" says Thomas Watters, lead author of the results at the Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, USA.

"Some investigators thought they might be a thin veneer overlaying topographic rises in the lowlands. The new data show that the MFF are massive deposits over 2.5 km thick in some places where MARSIS orbits pass over them," Watters added. The MFF deposits intrigue scientists because they are associated with regions that absorb certain wavelengths of Earth-based radar. This had led to them being called 'stealth' regions because they give no radar echo. The affected wavelengths are 3.5 to 12.6 centimetres. MARSIS, however, works at wavelengths of 50 to over 100 metres. At these wavelengths, the radar waves mostly pass through the MFF deposits creating subsurface echoes when the radar signal reflects off the plains material beneath.

A variety of scenarios have been proposed for the origin and composition of these deposits. Firstly, they could be volcanic ash deposits from now-buried vents or other nearby volcanoes. Second, they could be deposits of wind-blown materials eroded from other martian rocks. Thirdly, they could be ice-rich deposits, somewhat similar to the layered ice deposits at the poles of the planet, but formed when the spin axis of Mars tilts over, making the equatorial region colder.

Deciding between these scenarios is not easy, even with the new data. The MARSIS data reveal the electrical properties of the layers. These suggest that the layers could be poorly packed, fluffy or dusty material. However it is difficult to understand how porous material from wind-blown dust can be kilometres thick and yet not be compacted under the weight of the overlying material.

On the other hand, although the electrical properties are consistent with water ice layers, there is no other strong evidence for the presence of ice today in the equatorial regions of Mars. "If there is water ice at the equator of Mars, it must be buried at least several metres below the surface," says Jeffrey Plaut, MARSIS Co-Principal Investigator at the Jet Propulsion Laboratory, USA. This is because the water vapour pressure on Mars is so low that any ice near the surface would quickly evaporate.

So, the mystery of Mars's Medusae Fossae Formation continues. "It is still early in the game. We may get cleverer with our analysis and interpretation or we may only know when we go there with a drill and see for ourselves," says Plaut.

Giovanni Picardi at the University of Rome, La Sapienza, Principal Investigator of the experiment, says, "'Not only is MARSIS providing excellent scientific results but the team is also working on the processing techniques that will allow for more accurate evaluation of the characteristics of the subsurface layers and their constituent material. Hence, the possible extension of the mission will be very important to increase the number of observations over the regions of interest and improve the accuracy of the evaluations.

Sunday, November 4, 2007

Space station repairs end in success


A physician astronaut successfully stitched a torn solar panel Saturday, in a risky and unprecedented space walk to ensure an adequate power supply at the International Space Station, NASA said.

Astronaut Scott Parazynsky, a medical doctor by profession, spent more than four hours attached to the end of a robotic boom knitting together the damaged panels with makeshift wire "cufflinks" to fix the problems caused by a snagged wire when the panels unfurled.

"It appears you have some kind of surgery to do Dr. Parazinsky," shuttle commander Pamela Melroy told the experienced spacewalker as she watched his every move through binoculars from inside the Discovery probe, currently docked at the station (ISS).

The mission carried significant danger as touching the panels risked a shock from the 300-volt current they carried.

"Beautiful," Parazynsky said as he wrapped up the in-space fix-it job.

"Outstanding work," said Peggy Whitson, one of the controllers at Houston, Texas Mission Control.

The US National Aeronautics and Space Administration had made fixing the solar arrays the top priority for the Discovery shuttle mission because without it there was a risk the tear could spread and render the power-generating wing useless.

The mission unfolded live on television screens, with cameras and microphones aboard the international Space Station and on the astronaut's helmet catching all of the discussion and directions.

Parazynsky, 46, had to first cut the guy-wire that caused the problem; it quickly recoiled into a reel at the base of the wing.

To avoid the electric shock risk, Parazynsky had to work with a makeshift "hockey stick," an L-shaped tool wrapped in tape to prod the panels and help stitch through holes in the solar panels the five cufflink-like wire tabs fashioned by the astronauts aboard the ISS.

Ahead of the operation David Wolf, head of spacewalk training at NASA's center in Houston, said electrocution was "conceivable but extremely unlikely," adding that in such a case the astronaut would not be burned but could receive a "mild shock."

While he received coaching from both the ISS and the NASA Mission Control base at Houston, Texas, cameras showed Parazynsky twisting and bending the cufflinks to jam them through the holes to secure the panels.

Parazynski was attached by his feet to a 15-meter (49-foot) extension boom joined to the space station's 18-meter (59-foot) robotic arm, while Doug Wheelock stayed close watching the progress and giving directions to Stephanie Wilson and Dan Tani, who were maneuvering the robotic arm from inside the ISS.

After the stitching operation, NASA engineers using controls remotely in Houston slowly unfurled the solar pannel to its full extention of 76 meters (250 feet) -- when it snagged it was at 80 percent of its full length.

Wheelock and Parazynski, who closely watched the unfurling operation to spot any trouble, spent seven hours and 19 minutes in open space before completing the repair and returning to the ISS' decompression chamber at 1722 GMT.

The solar array, one of three on the space station, is critical to providing extra electricity for planned European and Japanese science labs.

The European Columbus laboratory is due to be delivered to the ISS in December and the Japanese Kibo lab in April 2008.

Working with the stiff spacesuit gloves made the job all the more difficult for Parazynski, who nevertheless deftly threaded the cufflinks into the holes.

Wolf earlier characterized the work as "like sewing with mittens on."

Parazynski was also farther out from the shuttle than on previous spacewalks -- an entire hour from safety instead of the customary 30 minutes if he needed to end the walk in an emergency.

If there are no more problems, Discovery is scheduled to undock from the space station on Monday and return to Earth on Wednesday. It blasted off on the mission on October 23.

Saturday, November 3, 2007

Hubble Sees Beautiful Carnage


Two big, beautiful spiral galaxies… tearing each other apart. The large, face-on spiral is NGC 3808, while its dueling partner is the smaller, edge-on NGC 3808A. And between the two is a long today tail of stars, gas and dust, transferring from one to the other.

The two galaxies are collectively known as Arp 87; just one of the hundreds of interacting galaxies seen by astronomers. It was cataloged by the famous Halton Arp in the 1960's, who maintained his Atlas of Peculiar Galaxies. And this collision is plenty peculiar, thanks to Hubble's optics and resolution of fine details.

A stream of gas, stars and dust is flowing from NGC 3808 to its companion, enveloping it in a starry embrace. Because the NGC 3808A is seen nearly edge-on, you can make out the twisting trail of stars wrapping around it. Both galaxies have been distorted by their gravitational interaction.

When galaxies interact, stars are born. And this is the case for Arp 87. The colour of the stars and the intensity of heated interstellar dust show that both galaxies are undergoing furious rates of star formation.

When Astronomers Fall Into A Black Hole

The German philosopher Arthur Schopenhauer once said, "The discovery of truth is prevented more effectively, not by the false appearance things present and which mislead into error, not directly by weakness of the reasoning powers, but by preconceived opinion, by prejudice." The most fundamental "prejudice" that has directed the space sciences for decades is the belief that, across cosmic distances, space is electrically inert. Throughout the Space Age, every new discovery has been interpreted through a lens that views gravity alone as the force that shapes the heavens.


This model of the cosmos also underpins our view of the Sun and our solar system. Ironically, as 20th century astronomers codified this perspective, the leading pioneers of plasma science were observing stupendous electric forces in space, and documenting the analogs in laboratory discharge phenomena. Through systematic observation and experiment, Hannes Alfven, the father of modern plasma science, came to a viewpoint contrary to that of mainstream astronomy. In his acceptance speech for the Nobel Prize, he warned astronomers that the study of plasma behavior requires attention to experimental plasma dynamics. But Alfven's warning went unheeded, allowing the cosmos to become, in Alfven's words, "...the playground of theoreticians who have never seen a plasma in a laboratory. Many of them still believe in formulae which we know from laboratory experiments to be wrong."

In the 21st century, mainstream astronomy faces a crisis of revolutionary proportions. Pervasive electrical phenomena observed in space confound astronomers who have insufficient training in experimental plasma science, and electrodynamics. In fact, with increasing (and inevitable) regularity, the language of the electrical theorists has entered the lexicon of mainstream astronomy, but in a manner that can only lead to greater confusion, both for the scientists and the general public.

The Newtonian vision of the cosmic theater imagines isolated bodies turning gear-like in a vacuum. The Electric Universe envisions electrical circuits embedded in a conducting medium whose components drive each other and may be in resonance. The differences between the two viewpoints is readily illustrated in a recent report from the New Scientist news service entitled, "Magnetic cocoons power energetic cosmic rays." (
http://space.newscientist.com/article/dn12818-magnetic-
cocoons-power-energetic-cosmic-rays.html)

The article discusses a theoretical solution for the "mystery" of ultra-high-energy cosmic rays. Standard theory has never succeeded in explaining the rays, which are thought to originate from far beyond our galaxy yet somehow make it all the way to Earth. Two scientists have proposed that the rays are "powered" by "magnetised cocoons of plasma" that were formed by jets of high-speed particles supposedly emitted by a "supermassive black hole."

The scientists suggest that over billions of years, the "magnetic fields" inside these "cocoons" induce electric fields, and "These electric fields are strong enough to accelerate cosmic rays to ultra-high energies."

And the astronomical community seems intrigued by the proposal. A Stanford University scientist quoted in the New Scientist piece referred to the theory as "the LEAST IMPLAUSIBLE explanation of ultra-high-energy cosmic rays."[Emphasis added]

A layman reading the New Scientist article faces the arduous task of distinguishing fact from theory, since the author makes little or no attempt to do so. What, for example, are we to think of the author's suggestion that the rays might be "produced near the Milky Way by the decay of super-heavy dark matter particles or by defects in space time"? Since scientists don't know what "dark matter" is (and even many standard cosmologists now question its existence), how can one meaningfully speculate on the existence of SUPER-HEAVY dark matter? And what practical significance could there be to a "defect in space-time," other than a neat plot twist to a Star Trek episode?

The author refers to "black holes" and "dark matter" as if they are FACTS, rather than speculative hypotheses. He refers to the "big bang" in a similar manner, even asserting that "every cubic centimetre of space contains about 400 relic photons from the BIG BANG FIREBALL."[Emphasis added] But when one examines the "explanation" for ultra-high-energy cosmic rays offered by the two scientists cited in the piece, every link in the chain of logic is based on assumptions that have no support in observation or experiment.

The first assumption is that black holes are real, and a black hole exists at the center of every galaxy. In fact, this assumption is so common that most science writers no longer bother to maintain any pretense of journalistic dispassion -- they simply assert that black holes exist and demand that the layman accept it as true. But no one has ever seen a black hole -- it is a mathematical concept invented to account for phenomena at the hearts of galaxies that are "too energetic" in a universe dominated by the pitifully weak force of gravity. The idea that a "nearly infinite compression" of matter (a black hole) can occur ANYWHERE has no experimental support whatever.

Furthermore, the black hole theory has had an embarrassing to non-existent PREDICTIVE record -- it has been and continues to be tweaked, modified, and overhauled to account for unexpected observations. For example, in its original formulation, magnetic fields had no role at all. But as astronomers with new instruments began to detect pervasive magnetic fields in space, the theorists were forced to redefine the envisioned "black hole activity" to account for them. All the while, they continue to ignore the electric currents on which magnetic fields depend.

The second assumption is that black holes (which we have no valid reason to believe exist) emit jets of high-speed particles. Since we were told for years that the gravitational force of black holes was too great for ANYTHING to escape, even LIGHT, this idea is particularly ironic. In fact, galaxies have been seen emitting high-energy X-rays and stupendous, filamentary jets across THOUSANDS of light years (requiring no small adjustment to black hole theory!).

In the case of the galaxy cluster Abell 400, a composite X-ray image revealed "radio jets immersed in a vast cloud of multimillion degree X-ray emitting gas that pervades the cluster." Astronomers claimed that the jets emanated from "two supermassive black holes" that were provoking the "merging" of two large galaxies.

But as was pointed out in a Picture of the Day on Thunderbolts.info: "Any substance with a temperature of 'multimillion' degrees cannot possibly be a gas: It will be a completely ionized plasma....(T)he X-rays in such cases are almost exclusively synchrotron radiation, not thermal radiation. That means the X-rays are emitted by very fast electrons spiraling in a strong magnetic field. The Abell 400 galaxies are under EXTREME ELECTRICAL STRESS.

"To generate the observed levels of energy seen in Abell 400 -- using nothing but the puny force of gravity -- more matter would have to be squeezed into a galaxy than a galaxy could hold. But the theorists are mathematicians, and they work with equations, not with real objects. This permits them to ignore empirical limits on density and let the amount of matter per unit volume increase without limit: The 'neutron stars' and 'black holes' conjured through this mathematical license can be placed wherever needed to explain away the stunning and potentially embarrassing energy excesses." (For an electrical interpretation of Abell 400, see
http://www.thunderbolts.info/tpod/2006/arch06/060501twoblackholes.htm)

The third assumption is that the jets of high-speed particles supposedly emitted by conjectured black holes can create "magnetic cocoons". These "giant magnetiszed cocoons of plasma," decaying over BILLIONS OF YEARS, finally produce electric fields strong enough to accelerate the cosmic rays. Here, the scientists are repeating precisely the error that Alfven so adamantly warned them against in his later career: they are presuming that magnetic fields are "frozen" into neutral plasma with no contribution from electric currents. Magnetic fields, Alfven insisted, are only part of the story. The electric currents that CREATE magnetic fields must not be overlooked, and contemporary attempts to model space plasma in the absence of electric currents will set astronomy and astrophysics on a course toward crisis, he said.

It isn't that the "cocoons" do not exist -- in fact it was plasma cosmologists who have identified the structure and dynamic of vast cellular forms in space. They are Langmuir sheaths, named after Irving Langmuir, who gave space plasma its name based on its "lifelike" qualities similar to those of blood plasma. Langmuir sheaths are seen at all scales of electrical activity in plasma. They signify regions of different charge separated by a cellular boundary. Across the walls of that sheath, an electric field exists. This electric field cannot have been produced by some "generator" inside the sheath; it must be due to larger regions of electric potential, however these regions are to be explained.

In an electric universe, galaxies are born from high-energy, electrical events whose signature can now be seen in space. Take a moment and consider the image above of the Radio Galaxy 3C31 (also called NGC 383). This galaxy is a MINISCULE object, little more than a dust mote, when seen against an immense display of highly energetic charged particles. Electrons in twin polar jets, accelerated to near the speed of light are the witnesses to the most intense electrical discharge activity known to science. Our instruments detect this activity through its synchrotron radiation and through the twin lobes of high-energy radio signals. So how is this huge region of electrical activity to be interpreted? In standard models, an electrically-neutral galaxy is asked to generate electrical activity across volumes of space THOUSANDS of times greater than the volume of the galaxy. But simple electrodynamics says this is impossible! How does a galactic-size, neutral object produce a vast domain of electrical activity around it? A plasma cosmologist looking at this image will see electric currents incomparably larger than the galaxy, being focused down by a plasma "pinch," at energy levels capable of lighting and organizing stars into the observed galactic structure. (For background, see Plasma Galaxies:
http://www.thunderbolts.info/tpod/2006/arch06/060602plasma-galaxy.htm)

The researchers cited in the New Scientist piece DO recognize an electrical-effect behind the "mysterious" cosmic rays, but in order to achieve this theoretical effect, they require a chain of bizarre events that have no analog in nature as we know it. We see in full display the crisis of which Alfven had forewarned -- "gravity-only" space scientists have no choice but to call on weird, untestable, unproven mechanics to achieve the "hard way" (or, in the words of one scientist, the "least implausible" way) what electricity does routinely, as demonstrated through decades of plasma experiments.

From an electrical perspective, the ultra-high-energy cosmic rays are not the result of a series of strange and unprovable events in deep space. They almost certainly originate in our own cosmic neighborhood, within the Milky Way, as a result of electrical discharge events well-modeled by plasma cosmologists. In other words, the rays do not need to travel across the Universe, overcoming the impedance of particles along the way. What plasma scientists call "z-pinches" in electric currents are nature's most efficient particle accelerators -- a phenomenon dominating much of plasma and "pulsed power" research today. The production of "relativistic speeds" (approaching the speed of light) does not require anything more than an electrically active galaxy. Both the galactic core and other focal points of electric discharge activity (such as planetary nebulae) are the logical places to investigate as the source of ultra-high-energy cosmic rays.