A team of astronomers from the Harvard-Smithsonian Center for Astrophysics (CfA) and the National Optical Astronomy Observatory (NOAO) examined a star forming region called W5, which lies about 6,500 light years away in the constellation Cassiopeia, using NASA’s Spitzer Space Telescope and the ground-based Two Micron All-Sky Survey (2MASS) to look for signs of dusty planetary disks around more than 500 massive stars of A and B spectral types – which are generally between 2 and 15 solar masses.

The team found that about ten per cent of all the stars examined had dusty disks – and of these 15 stars showed signs of a central gap suggestive of a new born Jupiter-scale planet clearing its orbit.

"The gravity of a Jupiter-sized object could easily clear the inner disk out to a radius of 10 to 20 astronomical units, which is what we see," said Lori Allen of NOAO. (An astronomical unit is the average distance between the Earth and the Sun).

The research team have also suggested that all massive stars may begin their life with a sizeable dusty disk of accreting material. However, the powerful radiation and stellar winds generated by such massive stars tend to destroy these disks rapidly. The stars observed in the W5 region are thought to be only two to five million years old, but most have already lost the dusty disk needed to make planets. On this basis, it seems that, at least for type A and B stars, planets must form quickly or not at all.

Prospects for finding life on such planets are slim. While the massive stars may foster a habitable zone of some kind – which in the case of life forms depending on liquid water as a chemical solvent, would be considerably further out from these stars than the Earth is from the Sun. However, such life forms would have limited future.

Life on Earth needed over three billion years just to evolve to the early differentiated body forms seen in the Cambrian explosion. Life on an exoplanet orbiting massive A or B type stars would have between 10 and 500 million years before its star grows to a red giant or a supernova.

"These stars aren't good targets in the hunt for extraterrestrials," said Xavier Koenig of the Harvard-Smithsonian CfA, who presented the research in a press conference at the AAS meeting today, "but they give us a great new way to get a better understanding of planet formation."

Planet hunters have detected an extrasolar planet that is only four times the mass of Earth, making it the second smallest exoplanet ever discovered. Astronomers using the 10-meter Keck I telescope at the Keck Observatory in Hawaii found the un-poetically named HD156668b, which has a mass of roughly 4.15 Earth masses. It orbits its parent star in just over four days and is located roughly 80 light years from Earth in the direction of the constellation Hercules. This adds to the growing list of so-called "Super-Earths" now being found.

“This is quite a remarkable discovery,” said astronomer Andrew Howard of the University of California at Berkeley. “It shows that we can push down and find smaller and smaller planets.”

The researchers used the radial velocity or wobble method, using Keck’s High Resolution Echelle Spectrograph, or HIRES instrument, to spread light collected from the telescope into its component wavelengths or colors. When the planet orbits around the back of the parent star, its gravity pulls slightly on the star causing the star’s spectrum to shift toward redder wavelengths. When the planet orbits in front of the star, it pulls the star in the other direction. The star’s spectrum shifts toward bluer wavelengths.

This graphic shows the data confirming the existence of extrasolar planet HD 156668b as discovered using Keck/HIRES. The planet has a mass of roughly 4.15 Earth masses and is the second smallest exoplanet discovered to date. It orbits its host star (HD 156668) every 4.6 days. Credit: Andrew Howard, UCB

“It’s been astronomers long-standing goal to find low mass planets, but they are really hard to detect,” Howard said. He added that the new discovery has implications for not only exoplanet research but also for solving the puzzle of how planets and planetary systems form and evolve.

Astronomers have pieces of the formation and evolutionary puzzle from the discovery of hundreds of high-mass planets. But, “there are important pieces, we don’t have yet. We need to understand how low mass planets, like super-Earths, form and migrate,” Howard said.

The goal of the Eta-Earth Survey for Low Mass Planets, which was the brainchild of fellow planet hunter Geoff Marcy, also from UCB, to find these super-Earths. So far the survey has discovered two near-Earth-mass planets with more are on the way, Howard said.

Other collaborators included , Debra Fischer of Yale University, John Johnson of the California of Institute of Technology and Jason Wright of Penn State University.

The discovery was announced at the 215th American Astronomical Society meeting in Washington D.C.

This illustration shows a pulsar's magnetic field (blue) creates narrow beams of radiation (magenta). Image credit: NASA

How do you detect a ripple in space-time itself? Well, you need hundreds of precision clocks distributed throughout the galaxy, and the Fermi gamma ray telescope has given astronomers a new way to find them.

The "clocks" in question are actually millisecond pulsars – city-sized, sun-massed stars of ultradense matter that spin hundreds of times per second. Due to their powerful magnetic fields, pulsars emit most of their radiation in tightly focused beams, much like a lighthouse. Each spin of the pulsar corresponds to a "pulse" of radiation detectable from Earth. The rate at which millisecond pulsars pulse is extremely stable, so they serve as some of the most reliable clocks in the universe.

Astronomers watch for the slightest variations in the timing of millisecond pulsars which might suggest that space-time near the pulsar is being distorted by the passage of a gravitational wave. The problem is, to make a reliable measurement requires hundreds of pulsars, and until recently they have been extremely difficult to find.

"We've probably found far less than one percent of the millisecond pulsars in the Milky Way Galaxy," said Scott Ransom of the National Radio Astronomy Observatory (NRAO).

Data from the Fermi gamma-ray space telescope, which started collecting data in 2008, have changed the way millisecond pulsars are detected. The Fermi telescope has identified hundreds of gamma-ray sources in the Milky Way. Gamma rays are high-energy photons, and they are produced near exotic objects, including millisecond pulsars.

"The data from Fermi were like a buried-treasure map," Ransom said. "Using our radio telescopes to study the objects located by Fermi, we found 17 millisecond pulsars in three months. Large-scale searches had taken 10-15 years to find that many."

Ransom and collaborator Mallory Roberts of Eureka Scientific used the National Science Foundation's Robert C. Byrd Green Bank Telescope (GBT) to find eight of the 17 new pulsars.

Right now astronomers have only barely enough millisecond pulsars to make a convincing gravitational wave detection, but with Fermi to help identify more pulsars, the odds of detecting these ripples in space-time are steadily increasing.

Ransom and Roberts announced their discoveries today at the American Astronomical Society's meeting in Washington, DC.

Although there has been plenty of moonlight to go around and frigid temperatures in many parts of the world, that's not going to stop what's happening in the sky. Not only is Mars back on the observing scene, but it's also getting close enough that details are becoming more and more clear. Would a little frost have stopped Percival Lowell? Darn right it wouldn't…. And it hasn't stopped John Chumack either.

"Despite the brutally cold weather last night, I decided to brave it for a couple of hours in my back yard to capture Mars." said John, "Mars is looking pretty nice and growing fast as it get closest and brightest at the end of this month. Currently it is 97% lit. This is my first attempt this opposition with a DMK firewire camera and 10" Schmidt Cassegrain Telescope."

Although John claims "poor seeing", using a camera helps to even the odds and his image reveals some outstanding details such as the North Polar Ice Cap (top), Acidalia Planitia (top center), Terra Meridiana (lower right), and Valles Marineris (lower left). For sharp-eyed observers, you can even spot some bright fluffy clouds forming on the far left limb and a small hint of a Southern Polar Cap, too. "Mars is only 12.87 arc seconds across" says Chumack, "Still small and a bit of a challenge to get details in less than good seeing."

So why encourage you to start your observations of Mars when it's difficult? Because not everyone everywhere is enjoying winter's grip and the more you practice, the better you can train your eye to catch fine details. When a planetary observer or photographer mentions "poor seeing" conditions, it doesn't necessarily mean clouds as much as it means an unstable atmosphere which causes the view to swim, or be difficult to bring into focus. You may find that a hazy night offers great stability, while a very clear one doesn't! It's all in chance, and you won't know what your chances are unless you take them. Right now Mars is well positioned in Leo and an easy catch for even those who are just beginning in astronomy.

To help you understand what you are seeing, you'll need to know which side of Mars you're looking at at any given time. When it comes to map generation, no one does it finer than Sky & Telescope Magazine and their Mars Profiler page which will help you pinpoint what's visible at the time and date you're viewing. While at first you may only see a small orange dot with a few dark markings, the key is not to give up… You don't need a camera to see details, only patience. It may take a few seconds, or several minutes before a moment of clarity and stability arrives, but when it does you will pick up a detail that you didn't notice at first glance. It may be a polar cap, or dark wedge of a surface feature… But they will appear. A great way to help train your eyes to catch these types of details is to sketch what you are seeing. Don't worry! No one will be around to grade your drawings. By focusing your attention and recording it on paper, you'll soon find that you're observing a lot more than you ever thought you could!

Move over, Percival… Mars is back and so are we.

A third giant red storm has flared up on Jupiter, joining the Great Red Spot and the recently developed Red Spot Junior. The spot, along with new measurements of record-high wind speeds on Red Spot Junior, come at a time when the solar system's largest planet is experiencing a time of global upheaval.

Jupiter's Great Red Spot is an ancient, hurricane-like storm that may have been raging for 340 years or more, based on early observations with telescopes. At three times the width of Earth, it is the largest storm in the solar system.

It was recently joined by a similar, but smaller storm called Red Spot Junior. Red Spot Junior grew out of the merger of three smaller, white storms between 1998 and 2000 and turned red in 2006. It is about the size of Earth.

Now, a third red spot, about half the size of Red Spot Junior, has broken out on the giant gaseous planet. The spot, previously a white storm, now appears red in Hubble Space Telescope images taken on 9 and 10 May. The observations were led by Imke de Pater of the University of California, Berkeley, US.

Ferocious winds

The cloud band containing the Great Red Spot has been especially stirred up, changing "from a rather bland, quiescent band surrounding the Great Red Spot just over a year ago to one that is incredibly turbulent at both sides of the spot", de Pater told New Scientist.

New measurements also suggest that Red Spot Junior's winds are increasing in ferocity. A team led by Andrew Cheng of the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, US, made the wind measurements by tracking cloud features in images taken 30 minutes apart by the New Horizons spacecraft as it whizzed by Jupiter in February 2007 on its way to Pluto.

The results suggest that Red Spot Junior's winds are now tearing around at nearly 620 kilometres per hour - matching the strongest winds ever observed in the Great Red Spot, and much faster than the winds in the largest of the three white storms that merged to make Red Spot Junior.

Destabilising force

"Maybe it's the increasing violence of the storm that enables it to become red, but that's somewhat speculative," team member Hal Weaver of APL told New Scientist.

But Philip Marcus of UC Berkeley, a member of de Pater's team, says he doubts that the winds have increased so much. Based on Hubble images taken in 2006, he calculates that Red Spot Junior's winds were moving at just 360 kilometres per hour.

Marcus thinks such a big change in wind speed between his observations in 2006 and the New Horizons flyby in 2007 is unlikely. "I'm sceptical, but open minded," he told New Scientist.

The new observations come at a time of global upheaval on Jupiter that has dramatically changed the planet's appearance.

The upheaval may be connected to a decades-long cycle proposed Marcus, a member of de Pater's team. According to this theory, varying wind patterns periodically destabilise Jupiter's atmosphere, leading to major changes on the planet.

This oblique view shows geological layers of rock exposed on a mound inside Gale Crater on Mars. Image credit: NASA/JPL-Caltech/University of Arizona/USGS

Is Mars more like a Peanut Buster Parfait, a granola-yogurt parfait, –or perhaps — maybe a seven-layer salad? Near the center of a Martian crater about the size of Connecticut, hundreds of exposed rock layers form a mound as tall as the Rockies and reveal a record of major environmental changes on Mars billions of years ago. According to a new report by geologists using instruments on the Mars Reconnaissance Orbiter to look at the "parfait" of layers inside Gale Crater, the layers show that Mars was likely wet at one point, but gradually dried over time.

"Looking at the layers from the bottom to the top, from the oldest to the youngest, you see a sequence of changing rocks that resulted from changes in environmental conditions through time," said Ralph Milliken from JPL. "This thick sequence of rocks appears to be showing different steps in the drying-out of Mars."

Layers of rock exposed in the lower portion of a tall mound near the center of Gale Crater on Mars exhibit variations in layer thickness and range between dark and light tones. Image credit: NASA/JPL-Caltech/University of Arizona

Layers of rock in the upper portion of a tall mound near the center of Gale Crater on Mars exhibit a regular thickness of several meters, unlike the less regular pattern of layers in the lower formation on the same mound. Image credit: NASA/JPL-Caltech/University of Arizona

"If you could stand there, you would see this beautiful formation of Martian sediments laid down in the past, a stratigraphic section that's more than twice the height of the Grand Canyon, though not as steep," said Bradley Thomson of the Johns Hopkins University Applied Physics Laboratory, Laurel, Md. He and John Grotzinger of the California Institute of Technology in Pasadena are Milliken's co-authors.

NASA selected Gale Crater in 2008 as one of four finalist sites for the Mars Science Laboratory rover, Curiosity, which has a planned launch in 2011. The finalist sites all have exposures of water-related minerals, and each has attributes that distinguish it from the others. This new report is an example of how observations made for evaluating the landing-site candidates are providing valuable science results even before the rover mission launches.

Saturn's plaid rings. Credit: NASA/JPL/Space Science Institute

And if you don't get the "plaid" reference, go watch Spaceballs.

The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on Jan. 11, 2010 at a distance of approximately 279,000 kilometers (173,000 miles) from Saturn.

Source: Cassini

Orion from the VISTA infrared telescope. Credit: ESO

Oh-oh-oh Orion! The new VISTA (Visible and Infrared Survey Telescope for Astronomy) infrared survey telescope has used its huge field of view to show the full splendor of the Orion Nebula. With its infrared eyes, it has peered deeply into dusty regions that are normally hidden to expose the curious behavior of the very active young stars buried there.

VISTA is the latest addition to ESO’s Paranal Observatory. It is the largest survey telescope in the world and is dedicated to mapping the sky at infrared wavelengths. The large (4.1-metre) mirror, wide field of view and very sensitive detectors make VISTA a unique instrument. This dramatic new image of the Orion Nebula illustrates VISTA’s remarkable powers.

The Orion Nebula is about 1,350 light-years from Earth. Although spectacular when seen through an ordinary telescope, what can be seen using visible light is only a small part of a cloud of gas in which stars are forming. Most of the action is deeply embedded in dust clouds and to see what is really happening astronomers need to use telescopes with detectors sensitive to the longer wavelength radiation that can penetrate the dust. VISTA has imaged the Orion Nebula at wavelengths about twice as long as can be detected by the human eye.

Four highlights of the new VISTA image of Orion. Credit: ESO

On the upper-left, the central region of VISTA’s view of the Orion Nebula is shown, centered on the four dazzling stars of the Trapezium. A rich cluster of young stars can be seen here that is invisible in normal, visible light images. In the lower-right panel the part of the nebula to the north of the center is shown. Here there are many young stars embedded in the dust clouds that are only apparent because their infrared glow can penetrate the dust and be detected by the VISTA camera. Many outflows, jets and other interactions from young stars are apparent, seen in the infrared glow from molecular hydrogen and showing up as red blobs. On the upper-right, a region to the west of center is shown. Here the fierce ultraviolet light from the Trapezium is sculpting the gas clouds into curious wavy shapes. A distant edge-on spiral galaxy is also seen shining right through the nebula. At the lower-left a region south of the center is shown. Each extract covers a region of sky about nine arcminutes across.

All these features are of great interest to astronomers studying the birth and youth of stars.

Source: ESO

Written by Nancy Atkinson

Launch of STS-130. Credit: Rich Yaeger

I am still shaking and still awestruck! I just witnessed my first rocket launch and space shuttle launch which also happens to be the last night launch for the space shuttle program. It was absolutely the most amazing thing I have ever witnessed. When the SRB's lit, night literally turned into day. The shuttle moved silently upward until the sound wave reached — and hit me — a couple of seconds later. I could feel the power of the launch from 3 miles away. The crackling and popping was amazingly loud, and the noise endured a very long time. So, so, so absolutely incredible! I wish I could better relate the awesomeness of seeing a shuttle launch! All I can say is that seeing the launch in person is nothing like watching it on TV or on your computer screen. But, I've embedded the video below, since I have run out or superlatives.

I was going to try and take a couple of pictures, but I ended up instead taking NASA Administrator Charlie Bolden's advice to just suck it up and enjoy the experience of the launch and not try to capture it on film — just let the professionals do that. (And yes, Charlie, I cried, too!) So the image above was taken by fellow journalist Rich Yaeger who graciously shared his image with Universe Today. Thanks Rich! Check out Rich's blog.

Also, check out Robert Pearlman's picturesque shot on CollectSPACE

And here's another great launch image from Alan Walters:

STS-130 launch. Credit: Alan Walters Photo

This is, I hope, a puzzle that cannot be answered by five minutes spent googling, a puzzle that requires you to cudgel your brains a bit, and do some lateral thinking.

What do David, Nicholas, and Ferdinand have in common?

Post your guesses in the comments section, and check back later at this same post to find the answer. To make this puzzle fun for everyone, please don’t include links or extensive explanations with your answer, until after the answer has been given. Good luck!

Answer has now been posted below:

Small Magellanic Cloud. Image credit: NASA/ESA/HST

Malin1 (Hubble Space Telescope image courtesy of Aaron Barth)

Mayall's Object (Hubble Space Telescope)

Einstein, whose theory of general relativity has just passed another test

How did Steven Chu (US Secretary of Energy, though this work was done while he was at the University of California Berkeley), Holger Müler (Berkeley), and Achim Peters (Humboldt University in Berlin) beat the previous best gravitational redshift test (in 1976, using two atomic clocks – one on the surface of the Earth and the other sent up to an altitude of 10,000 km in a rocket) by a staggering 10,000 times?

By exploited wave-particle duality and superposition within an atom interferometer!

Cesium atom interferometer test of  gravitational redshift (Courtesy Nature)

Gravitational redshift is an inevitable consequence of the equivalence principle that underlies ge

neral relativity. The equivalence principle states that the local effects of gravity are the same as those of being in an accelerated frame of reference. So the downward force felt by someone in a lift could be equally due to an upward acceleration of the lift or to gravity. Pulses of light sent upwards from a clock on the lift floor will be redshifted when the lift is accelerating upwards, meaning that this clock will appear to tick more slowly when its flashes are compared at the ceiling of the lift to another clock. Because there is no way to tell gravity and acceleration apart, the same will hold true in a gravitational field; in other words the greater the gravitational pull experienced by a clock, or the closer it is to a massive body, the more slowly it will tick.

Confirmation of this effect supports the idea that gravity is geometry – a manifestation of spacetime curvature – because the flow of time is no longer constant throughout the universe but varies according to the distribution of massive bodies. Exploring the idea of spacetime curvature is important when distinguishing between different theories of quantum gravity because there are some versions of string theory in which matter can respond to something other than the geometry of spacetime.

Gravitational redshift, however, as a manifestation of local position invariance (the idea that the outcome of any non-gravitational experiment is independent of where and when in the universe it is carried out) is the least well confirmed of the three types of experiment that support the equivalence principle. The other two – the universality of freefall and local Lorentz invariance – have been verified with precisions of 10^-13 or better, whereas gravitational redshift had previously been confirmed only to a precision of 7×10^-5.

In 1997 Peters used laser trapping techniques developed by Chu to capture cesium atoms and cool them to a few millionths of a degree K (in order to reduce their velocity as much as possible), and then used a vertical laser beam to impart an upward kick to the atoms in order to measure gravitational freefall.

Now, Chu and Müller have re-interpreted the results of that experiment to give a measurement of the gravitational redshift.

In the experiment each of the atoms was exposed to three laser pulses. The first pulse placed the atom into a superposition of two equally probable states – either leaving it alone to decelerate and then fall back down to Earth under gravity's pull, or giving it an extra kick so that it reached a greater height before descending. A second pulse was then applied at just the right moment so as to push the atom in the second state back faster toward Earth, causing the two superposition states to meet on the way down. At this point the third pulse measured the interference between these two states brought about by the atom's existence as a wave, the idea being that any difference in gravitational redshift as experienced by the two states existing at difference heights above the Earth's surface would be manifest as a change in the relative phase of the two states.

The virtue of this approach is the extremely high frequency of a cesium atom's de Broglie wave – some 3×10²⁵Hz. Although during the 0.3 s of freefall the matter waves on the higher trajectory experienced an elapsed time of just 2×10^-20s more than the waves on the lower trajectory did, the enormous frequency of their oscillation, combined with the ability to measure amplitude differences of just one part in 1000, meant that the researchers were able to confirm gravitational redshift to a precision of 7×10^-9.

As Müller puts it, "If the time of freefall was extended to the age of the universe – 14 billion years – the time difference between the upper and lower routes would be a mere one thousandth of a second, and the accuracy of the measurement would be 60 ps, the time it takes for light to travel about a centimetre."

Müller hopes to further improve the precision of the redshift measurements by increasing the distance between the two superposition states of the cesium atoms. The distance achieved in the current research was a mere 0.1 mm, but, he says, by increasing this to 1 m it should be possible to detect gravitational waves, predicted by general relativity but not yet directly observed.

Sources: Physics World; the paper is in the 18 February, 2010 issue of Nature

The Fornax dwarf galaxy is one of our Milky Way’s neighbouring dwarf galaxies. The Milky Way is, like all large galaxies, thought to have formed from smaller galaxies in the early days of the Universe. These small galaxies should also contain many very old stars, just as the Milky Way does, and a team of astronomers has now shown that this is indeed the case. This image was composed from data from the Digitized Sky Survey 2. Credit: ESO

Astronomer sleuths have solved a cosmic mystery by finding primitive stars that have been stealthily concealed. Using ESO’s Very Large Telescope a group of astronomers have uncovered an important astrophysical puzzle concerning the oldest stars in our galactic neighborhood — which is crucial for our understanding of the earliest stars in the Universe. . “We have, in effect, found a flaw in the forensic methods used until now,” said Else Starkenburg, lead author of a paper reporting the new findings. “Our improved approach allows us to uncover the primitive stars hidden among all the other, more common stars.”

Primitive stars are thought to have formed from material forged shortly after the Big Bang, 13.7 billion years ago. They typically have less than one thousandth the amount of chemical elements heavier than hydrogen and helium found in the Sun and are called “extremely metal-poor stars.” They belong to one of the first generations of stars in the nearby Universe. Such stars are extremely rare and mainly observed in the Milky Way.

The Sculptor dwarf galaxy is one of our Milky Way’s neighbouring dwarf galaxies. Credit: ESO/Digitized Sky Survey 2

Element abundances are measured from spectra, which provide the chemical fingerprints of stars. The Dwarf galaxies Abundances and Radial-velocities Team used the FLAMES instrument on ESO’s Very Large Telescope to measure the spectra of over 2000 individual giant stars in four of our galactic neighbors, the Fornax, Sculptor, Sextans and Carina dwarf galaxies. Since the dwarf galaxies are typically 300,000 light years away — which is about three times the size of our Milky Way — only strong features in the spectrum could be measured, like a vague, smeared fingerprint. The team found that none of their large collection of spectral fingerprints actually seemed to belong to the class of stars they were after, the rare, extremely metal-poor stars found in the Milky Way.

The team of astronomers around Starkenburg has now shed new light on the problem through careful comparison of spectra to computer-based models. They found that only subtle differences distinguish the chemical fingerprint of a normal metal-poor star from that of an extremely metal-poor star, explaining why previous methods did not succeed in making the identification.

The astronomers also confirmed the almost pristine status of several extremely metal-poor stars thanks to much more detailed spectra obtained with the UVES instrument on ESO’s Very Large Telescope. “Compared to the vague fingerprints we had before, this would be as if we looked at the fingerprint through a microscope,” explains team member Vanessa Hill. “Unfortunately, just a small number of stars can be observed this way because it is very time consuming.”

“Among the new extremely metal-poor stars discovered in these dwarf galaxies, three have a relative amount of heavy chemical elements between only 1/3000 and 1/10 000 of what is observed in our Sun, including the current record holder of the most primitive star found outside the Milky Way,” said team member Martin Tafelmeyer.

“Not only has our work revealed some of the very interesting, first stars in these galaxies, but it also provides a new, powerful technique to uncover more such stars,” concluded Starkenburg. “From now on there is no place left to hide!”

Source: ESO

New results from the Chandra X-Ray Observatory suggests that the majority of Type Ia supernovae occur due to the merger of two white dwarfs. This new finding provides a major advance in understanding the type of supernovae that astronomers use to measure the expansion of the Universe, which in turns allows astronomers to study dark energy which is believed to pervade the universe. "It was a major embarrassment that we still didn't know the conditions and progenitor systems of some the most spectacular explosions in the universe," said Marat Gilfanov of the Max Planck Institute for Astrophysics, at a press conference with reporters today. Gilfanov is the lead author of the study that appears in the Feb. 18 edition of the journal Nature.

Type Ia supernovae serve as cosmic mile markers to measure expansion of the universe. Because they can be seen at large distances, and they follow a reliable pattern of brightness. However, until now, scientists have been unsure what actually causes the explosions.

Most scientists agree a Type Ia supernova occurs when a white dwarf star — a collapsed remnant of an elderly star — exceeds its weight limit, becomes unstable and explodes. The two leading candidates for what pushes the white dwarf over the edge are the merging of two white dwarfs, or accretion, a process in which the white dwarf pulls material from a sun-like companion star until it exceeds its weight limit.

"Our results suggest the supernovae in the galaxies we studied almost all come from two white dwarfs merging," said co-author Akos Bogdan, also of Max Planck. "This is probably not what many astronomers would expect."

The difference between these two scenarios may have implications for how these supernovae can be used as "standard candles" — objects of a known brightness — to track vast cosmic distances. Because white dwarfs can come in a range of masses, the merger of two could result in explosions that vary somewhat in brightness.

Because these two scenarios would generate different amounts of X-ray emission, Gilfanov and Bogdan used Chandra to observe five nearby elliptical galaxies and the central region of the Andromeda galaxy. A Type Ia supernova caused by accreting material produces significant X-ray emission prior to the explosion. A supernova from a merger of two white dwarfs, on the other hand, would create significantly less X-ray emission than the accretion scenario.

The scientists found the observed X-ray emission was a factor of 30 to 50 times smaller than expected from the accretion scenario, effectively ruling it out.

So, for example, the Chandra image above would be about 40 times brighter than observed if Type Ia supernova in the bulge of this galaxy were triggered by material from a normal star falling onto a white dwarf star. Similar results for five elliptical galaxies were found.

This implies that white dwarf mergers dominate in these galaxies.

An open question remains whether these white dwarf mergers are the primary catalyst for Type Ia supernovae in spiral galaxies. Further studies are required to know if supernovae in spiral galaxies are caused by mergers or a mixture of the two processes. Another intriguing consequence of this result is that a pair of white dwarfs is relatively hard to spot, even with the best telescopes.

"To many astrophysicists, the merger scenario seemed to be less likely because too few double-white-dwarf systems appeared to exist," said Gilfanov. "Now this path to supernovae will have to be investigated in more detail."

Source: NASA

Artist's impression of BD+20 1790b, the youngest exoplanet yet discovered. Credit: M. Hernon Obispo

Overcoming interference from a very active young sun-like star, a group of astronomers were able to find what they determined is the youngest exoplanet yet discovered. BD+20 1790b is 35 million years old (Earth is about 100 times older at 4.5 billion years) and is located about 83 light years away from our planet. Previously, the youngest known exoplanet was about 100 million years old. Studying this planet will help our understanding of planetary evolution.

While this new-found planet is young, it is a whopper, at six times the mass of Jupiter. It orbits a young active star at a distance closer than Mercury orbits the Sun.

Most planet-search surveys tend to target much older stars, with ages in excess of a billion years. Young stars usually have intense magnetic fields that generate solar flares and sunspots, which can mimic the presence of a planetary companion and so can make extremely difficult to disentangle the signals of planets and activity.

BD+201790 is a very active star, and astronomers announced last year that it could possibly have a companion. An international collaboration of astronomers, led by Dr. Maria Cruz Gálvez-Ortiz and Dr. John Barnes were able to "weed out" the data to determine the planet was actually there.

“The planet was detected by searching for very small variations in the velocity of the host star, caused by the gravitational tug of the planet as it orbits – the so-called “Doppler wobble technique,” said Gálvez-Ortiz. "Overcoming the interference caused by the activity was a major challenge for the team, but with enough data from an array of large telescopes the planet’s signature was revealed.”

The team has been observing the star for the last five years at different telescopes, including the Observatorio de Calar Alto (Almería, Spain) and the Observatorio del Roque de los Muchachos (La Palma, Spain).

Source: Alpha Galileo

This figure illustrates the unexpected and bizarre pattern of daytime temperatures found on Saturn's small inner moon Mimas (396 kilometers, or 246 miles, in diameter). Credit: NASA/JPL/GSFC/SWRI/SSI

Mimas has drawn a fair amount of attention with its "Death Star"-like appearance, but with new images from the Cassini spacecraft, this icy moon of Saturn has just gotten a lot more interesting. The highest-resolution-yet temperature map and images of Mimas reveal surprising patterns on the surface of the small moon, including unexpected hot regions that resemble "Pac-Man" eating the Death Star crater (officially known as Herschel Crater), as well as striking bands of light and dark in crater walls. "After much deliberation, we have concluded: Mimas is NOT boring," said Carolyn Porco, Cassini imaging team leader, in an e-mail about the new images. "Who knew?!" And best of all, Porco added, "be sure you have a pair of red/green glasses handy 'cause you won't want to miss peering into gigantic Herschel crater in 3D!"

Cassini collected the data on Feb. 13, and Porco said the team has spent some quality time poring over the images. She said the details in the moon's craters that reminded the imaging team of features seen on Phoebe and Hyperion, plus the thermal signature is very peculiar and the team can't yet explain it.

Herschel Crater in 3-D. Credit: NASA/JPL/Space Science Institute. Click for larger version.

Scientists were expecting smoothly varying temperatures peaking in the early afternoon near the equator. Instead, the warmest region was in the morning, along one edge of the moon's disk, making a sharply defined Pac-Man shape, with temperatures around 92 Kelvin (minus 294 degrees Fahrenheit). The rest of the moon was much colder, around 77 Kelvin (minus 320 degrees Fahrenheit). A smaller warm spot – the dot in Pac-Man's mouth – showed up around Herschel, with a temperature around 84 Kelvin (minus 310 degrees Fahrenheit).

The warm spot around Herschel makes sense because tall crater walls (about 5 kilometers, or 3 miles, high) can trap heat inside the crater. But scientists were completely baffled by the sharp, V-shaped pattern.

"We suspect the temperatures are revealing differences in texture on the surface," said John Spencer, who works with Cassini's composite infrared spectrometer. "It's maybe something like the difference between old, dense snow and freshly fallen powder."

Denser ice quickly conducts the heat of the sun away from the surface, keeping it cold during the day. Powdery ice is more insulating and traps the sun's heat at the surface, so the surface warms up.

Even if surface texture variations are to blame, scientists are still trying to figure out why there are such sharp boundaries between the regions, Spencer said. It is possible that the impact that created Herschel Crater melted surface ice and spread water across the moon. That liquid may have flash-frozen into a hard surface. But it is hard to understand why this dense top layer would remain intact when meteorites and other space debris should have pulverized it by now, Spencer said.

Dark regions below bright crater walls and streaks on some of the walls are seen in this mosaic of Saturn's moon Mimas. Credit: NASA/JPL/Space Science Institute. Click for larger version.

The pattern may appear because of the way the surface of Mimas ages, said Paul Helfenstein, a Cassini imaging team associate based at Cornell University, Ithaca, N.Y. Over time, the moon's surface appears to accumulate a thin veil of silicate minerals or carbon-rich particles, possibly because of meteor dust falling onto the moon, or impurities already embedded in surface ice.

As the sun's warming rays and the vacuum of space evaporate the brighter ice, the darker material is concentrated and left behind. Gravity pulls the dark material down the crater walls, exposing fresh ice underneath. Although similar effects are seen on other moons of Saturn, the visibility of these contrasts on a moon continually re-paved with small particles from the E ring helps scientists estimate rates of change on other satellites.

"These processes are not unique to Mimas, but the new high-definition images are like Rosetta stones for interpreting them," Helfenstein said.

How do the folks from UnmannedSpaceflight do it?!! They keep surpassing themselves with every new flyover video! We've posted some Mars flyover videos before, created by UMSF founder Doug Ellison. Now, colleague Adrian Lark — who has been working on creating animations and enhanced images with data from the Mars missions for several years — has produced new features on the videos. This latest, which flies you around the scarp surrounding Olympus Mons has speed and height information as well as a context map included on the video. "The data I am using is generated from the HiRISE camera onboard the Mars Reconnaissance Orbiter," Adrian told me. "The elevation data has a spatial resolution of 1 meter and the image data has a spatial resolution of 25 centimeters. There is no vertical exaggeration in any of the videos."

Also, Adrian has experimented with You Tube's stereoscopic 3-D player, providing a 3-D experience of flying through Candor Chasma. IMAX, watchout! You've got competition!

So hang on while you watch these incredible videos! See more below, and also Adrian shared with me a little about his software and how he creates these flyover videos.

The videos are created using actual, high-resolution data from the HiRISE camera — DEM (Digital Elevation Model)– also known as DTM Digital Terrain Model files.

Click here to watch the new 3-D experimental video.

Adrian's regular, non-3-D version of his Candor Chasma video recently went viral across the web, hitting websites like Huffington Post and more (watch it here).

"The videos were produced using software I originally designed to visualize the MOLA data in 2001," Adrian said. "The software, called Mars Explorer, is a real-time rendering engine for visualizing 3D terrain data interactively."

Adrian said the Mars Explorer software renders at about 60 frames per second on a PC with a moderately powerful graphics card when not outputting video. "When creating videos it runs at about one tenth of that speed. The 4 minute 50 second Candor Chasma video took about half an hour to generate," he said. "The software requires the elevation and image data in raw binary format so I first have to pre-process the HiRISE DTM and image data into this format. This process takes about an hour.

One of my favorites is one Adrian created of flying through Gale Crater, above, which includes the sun in the sky and even "glare" of the sun off the "lens" of your camera (or the windshield on your Mars hovercraft! – the sun and glare can also be seen in the Olympus Mons video, top). But he says the earlier videos he created, such as the Gale crater animation, did not utilize the full image resolution that he now has by making his software more memory efficient. "I can now use the data at its full resolution," he said. "I have to crop some of the larger datasets such as the Mojave crater DTM because they require more system RAM than I currently have."

About the sun and glare, Adrian said, "The shadows in the Gale crater animation do not correspond correctly to the position of the sun. The sun should be to the left and possibly higher. The sun glare is an effect I programmed that brightens the whole screen by an amount depending on the angle between the sun and view direction."

In the Candor Chasma and Gale crater videos the camera is traveling roughly at 160km/h at an altitude of 100 meters.

Simply amazing! Thanks to Adrian for sharing and explaining how he creates these videos. He also said he will be making the Mars Explorer software freely available for download from his website soon.

Lunar Landscape. Credit: LROC; Goddard Space Flight Center and U of AZ, 3-D modeling and rendering by Bernhard Braun.

You may recall Bernhard Braun as the wizard from UnmannedSpaceflight.com who created the amazing 3-D images of the Mars avalanche. Now he's created incredible planetary landscapes for a different world: the Moon. "Actually, this has been my very first attempt with lunar imagery after my previous work has almost been exclusively devoted to Mars," Braun said. The special software he developed can create three dimensional images from one 2-dimensional picture, but he says the real stars are the spacecraft that gather the data, the Lunar Reconnaissance Orbiter and the Mars Reconnaissance Orbiter. "It is the unprecedented quality together with the unprecedented availability of the raw data that opens the door for everyone to explore new ideas and processing techniques," Braun said.

See below for more stunning from-the-surface 3-D looks at the Moon – no special 3-D glasses needed!

Lunar Landscape. Credit: LROC; Goddard Spaceflight Center, U of AZ, 3-d rendering and modeling by Bernhard Braun.

I asked Braun if working with images from the Moon was different than working with Mars images. "Creating the single-image shading-derived DEMs from the Moon imagery is both easier and more difficult at the same time when compared to the same process applied to Mars images," he said. "It's easier because the lunar surface does not vary as much in its intrinsic albedo, i.e. the visible brightness variations are almost exclusively caused by variations in surface topography, especially at low illumination angles, which can be exploited by the reconstruction algorithm to derive high precision 3D geometry."

But the work is more difficult because of the totally black shadows on the Moon due to lack of any atmosphere. "So on the Moon any shadows are virtually featureless areas where the 3-D reconstruction algorithm cannot infer anything about the structure of the invisible shadowed surface," Braun said. "This is different on Mars, where the shadowed areas are usually lit indirectly by considerable amounts of ambient light scattered by dust particles suspended in the atmosphere. So the 3-D models of the Mars surface can be more complete, showing surface details even in shadowed areas."

Lunar Landscape. Credit: LROC; Goddard Spaceflight Center, U of AZ, 3-d rendering and modeling by Bernhard Braun.

"All in all it's a lot of fun to play around with both camera and sun positions until an interesting landscape shot is found," Braun said. "I would like to add that much of the credit must really go to those true wizards at NASA/JPL for not only making and bringing to orbit these almost unearthly powerful cameras like LROC and HiRISE … but also for sharing the whole image catalog via the internet with everyone in the world!"

Braun said he hopes to tackle 3-D views of the Apollo landing sites — which we cannot wait to see!

Artist’s schematic impression of the distortion of spacetime by a supermassive black hole at the centre of a galaxy. The black hole will swallow dark matter at a rate which depends on its mass and on the amount of dark matter around it. Image: Felipe Esquivel Reed.

There's the common notion that black holes suck in everything in the nearby vicinity by exerting a strong gravitational influence on the matter, energy, and space surrounding them. But astronomers have found that the dark matter around black holes might be a different story. Somehow dark matter resists 'assimilation' into a black hole.

About 23% of the Universe is made up of mysterious dark matter, invisible material only detected through its gravitational influence on its surroundings. In the early Universe clumps of dark matter are thought to have attracted gas, which then coalesced into stars that eventually assembled the galaxies we see today. In their efforts to understand galaxy formation and evolution, astronomers have spent a good deal of time attempting to simulate the build up of dark matter in these objects.

Dr. Xavier Hernandez and Dr. William Lee from the National Autonomous University of Mexico (UNAM) calculated the way in which the black holes found at the center of galaxies absorb dark matter. These black holes have anything between millions and billions of times the mass of the Sun and draw in material at a high rate

.

The researchers modeled the way in which the dark matter is absorbed by black holes and found that the rate at which this happens is very sensitive to the amount of dark matter found in the black holes’ vicinity. If this concentration were larger than a critical density of 7 Suns of matter spread over each cubic light year of space, the black hole mass would increase so rapidly, hence engulfing such large amounts of dark matter, that soon the entire galaxy would be altered beyond recognition.

“Over the billions of years since galaxies formed, such runaway absorption of dark matter in black holes would have altered the population of galaxies away from what we actually observe,” said Hernandez

Their work therefore suggests that the density of dark matter in the centers of galaxies tends to be a constant value. By comparing their observations to what current models of the evolution of the Universe predict, Hernandez and Lee conclude that it is probably necessary to change some of the assumptions that underpin these models – dark matter may not behave in the way scientists thought it did.

There work appears in the journal Monthly Notices of the Royal Astronomical Society.

Cosmonaut Yuri Gidzenko floats inside Leonardo during its first flight to the ISS. Leonardo will become a permanant module later in 2010. Credit: NASA

There might be a new favorite hang-out for astronauts aboard the International Space Station later this year. The Multi Purpose Logistics Module (MPLM) known as Leonardo – which will be going to the ISS on the upcoming STS-131 mission carrying cargo and supplies — will be transformed after the mission into a Permanent Multipurpose Module (PMM), and brought up to stay on the station on STS-133 as a storeroom for supplies. But it might also become a haven to get away from it all.

"The thought is, the PMM might become sort of a 'man cave'," said Mike Kinslow, the Boeing payload manager out at Kennedy Space Center. "It won't have all the background noise of fans, computers and other equipment running like in the laboratories, so it will be a quieter atmosphere that might appeal to the astronauts during their off-duty hours."

No plans for a big screen TV Kinslow said, but there will be ports for computers, and since internet is now available on the ISS, Leonardo could be the location of choice to compose emails to loved ones back home, or do a little Twittering.

Another interesting piece of hardware scheduled to fly on the PMM is the Robonaut 2, NASA's second generation of dexterous robots with a human-like torso that can work with tools and one day are envisioned to be able to do EVA work outside the ISS. But for now, R2 will be tested inside the station in zero-g. "It will be used on orbit for routine maintenance indoors only." said Kinslow, "This is not an external unit."

It has a "head" with a vision system, with hands that can do work, controlled by virtual-reality-like operation. Any chance R2 could be programmed to serve drinks or bring food into the man cave?

Turning Leonardo into a permanent module will take some work, said NASA Payload Manager Joe Delai. "Once it returns from this flight we will beef up the external shield and change things internally to become a permanent module. It will be about a four month process to get it ready."

Leonard being attached to the ISS on a previous mission. Credit: NASA TV

Kinslow said shields for an MPLM are lighter weight because they are only meant to be on orbit for 2 weeks at a time. "Leonardo will be plated with a multilevel Kevlar blanket, the same type of exterior shielding other modules have, which is similar to armor plating, to protect against meteorite or debris impact. Internally, not a lot of changes will be made," he said. "It already has a ventilation system like a normal module, but will need a computer system and a few other additions."

Leonardo won't be outfitted with a sleep station or crew quarters because it might be in a more vulnerable position for radiation or debris hits. "They don't really want crew to get in and sleep because of the shielding," Kinslow said. "It will be a storage module, and we're discussing putting exercise equipment in there."

The PMM will be berthed on the Node 1 nadir, or Earth-facing port. Leonardo measures about 6.5 meters (21 feet) long and 4.5 meters (15 feet) in diameter.

STS-131 is currently scheduled for an April 5 launch, and STS-133 is shooting for a September 2010 launch.

Just a note on the ISS internet: T.J. Creamer, who is on board the station now told Universe Today that they aren't able to have streaming video or download large files. "In terms of download speeds – you know, back in the old days, it kind of compares to 9.6 and the 14.4 kilobyte modems, so it's not really fast enough to do large file exchange or videos, but it certainly lets us to do browsing and the fun reading we want to do, or get caught up on current events on that day. It's a nice outreach for us, and of course you've heard about the Twittering which is a nice feature that we can partake in also."

Mosaic of the area adjacent to ‘Home Plate’ where Spirit remains stuck as 4th Martain winter experienced by Spirit approaches. Spirit has entered hibernation as of March 30, 2010 due to tripping a low power fault as a result of declining sunlight. Mosaic shows smooth area, foreground, that concealed slippery water related sulfate material where rover became stuck, but made great Science Discoveries ! Will Spirit survive the extremely harsh bone chilling cold temperatures of winter ? Credit: Kenneth Kremer, Marco DiLorenzo, NASA/JPL/Cornell/Spaceflight Now

“Well, we knew it was coming… in fact, I'm surprised it didn't happen earlier”, Steve Squyres told me today, April 1. Squyres is the Chief Scientist for the Mars rover twins, Spirit and Opportunity.

“The vehicle is all tucked in and ready to hibernate, and we have high hopes that we'll be back in business come springtime. But it's gonna be a long winter,” Squyres added.

The team was anticipating Spirit to experience a low-power fault about this time due to declining energy production from the wing-like solar panels. As winter approaches in the Martian southern hemisphere, the daily quantity of sunlight impinging on the power producing panels declines daily.

Energy production from the solar arrays had dropped to only 134 watt-hours on March 22. So, the most likely explanation for the missing downlink is that Spirit did go into that low-power fault taking her batteries off-line, sometime between the last downlink on Sol 2210 (March 22, 2010), and Sol 2218 (March 30, 2010).

Mosaic of microscopic images of Spirit underbelly on Sol 1925 (June 2009) showing the predicament of being stuck at Troy with wheels buried in the sulfate-rich martian soil. The sulfate deposits formed by aqueous (water-related) processes when this area dubbed “Home Plate’ was volcanically active. This false color mosaic has been enhanced and stretched to bring out additional details about the surrounding terrain and embedded wheels and distinctly show a pointy rock perhaps in contact with the underbelly. Spirit fortuitously discovered extensive new evidence for an environment of flowing liquid water at this location on Mars adjacent to ‘Home Plate’, an eroded over volcanic feature. Credit: Marco Di Lorenzo, Ken Kremer - NASA/JPL/Cornell

In hibernation mode, Spirits master clock keeps on ticking, but communications and other activities are suspended in order to channel all available energy into powering the critical survival heaters necessary to save the rovers electronics as well as to try to recharge the batteries and attempt to wake up. When the battery charge is adequate, the rover attempts to wake up and communicate on a schedule it knows.

“Components within the rover electronic module (REM) inside the rover's warm electronic box (WEB) are experiencing record low temperatures,” says Doug McCuistion, the director of Mars Exploration at NASA Headquarters in Washington, DC, in an interview about Spirit’s predicament. “So far, the coldest temperatures recorded within the REM by one reached a low temperature of -41.5 degrees Celsius (-42.7 degrees Fahrenheit)”. This occurred just prior to the loss in communications.

“The REM electronics rack is located inside the WEB and is about a half meter cube in size”, McCuistion told me. “The expectation is for the REM hardware to reach -55C at the coldest part of the winter. We have tested the REM down to -55C”.

“Spirit's lowest power production during a single sol (so far) was during a dust storm in November of 2008. For that one sol, Spirit's solar arrays produced only 89 watt-hours of energy,” McCuistion said.

“We may not hear from Spirit again for weeks or months, but we will be listening at every opportunity, and our expectation is that Spirit will resume communications when the batteries are sufficiently charged," said John Callas of NASA's Jet Propulsion Laboratory who is project manager for Spirit and Opportunity.

Spirit has been stuck at a place called ‘Troy’ since becoming mired in a sand trap of soft soil in April 2009. While driving on the western edge of ‘Home Plate’, she unknowingly broke through a hard surface crust (perhaps 1 cm thick) of water related sulfate materials and sank into hidden soft sand beneath. At Troy she made a great science discovery by finding evidence of the past flow of liquid water on the surface of Mars.

The GOODS South Field. ESO/M. Hayes

Astronomers have long known that many surveys of distant galaxies miss 90% of their targets, but they didn't know why. Now, astronomers have determined that a large fraction of galaxies whose light took 10 billion years to reach us have gone undiscovered. This was found with an extremely deep survey using two of the four giant 8.2-meter telescopes that make up ESO’s Very Large Telescope (VLT) and a unique custom-built filter. The survey also helped uncover some of the faintest galaxies ever found at this early stage of the Universe.

Astronomers frequently use the strong, characteristic “fingerprint” of light emitted by hydrogen known as the Lyman-alpha line, to probe the amount of stars formed in the very distant Universe Yet there have long been suspicions that many distant galaxies go unnoticed in these surveys. A new VLT survey demonstrates for the first time that this is exactly what is happening. Most of the Lyman-alpha light is trapped within the galaxy that emits it, and 90% of galaxies do not show up in Lyman-alpha surveys.

“Astronomers always knew they were missing some fraction of the galaxies in Lyman-alpha surveys,” explains Matthew Hayes, the lead author of the paper, published this week in Nature, “but for the first time we now have a measurement. The number of missed galaxies is substantial.”

To figure out how much of the total luminosity was missed, Hayes and his team used the FORS camera at the VLT and a custom-built narrowband filter to measure this Lyman-alpha light, following the methodology of standard Lyman-alpha surveys. Then, using the new HAWK-I camera, attached to another VLT Unit Telescope, they surveyed the same area of space for light emitted at a different wavelength, also by glowing hydrogen, and known as the H-alpha line. They specifically looked at galaxies whose light has been traveling for 10 billion years (redshift 2.2), in a well-studied area of the sky, known as the GOODS-South field.

“This is the first time we have observed a patch of the sky so deeply in light coming from hydrogen at these two very specific wavelengths, and this proved crucial,” said team member Goran Ostlin. The survey was extremely deep, and uncovered some of the faintest galaxies known at this early epoch in the life of the Universe. The astronomers could thereby conclude that traditional surveys done using Lyman-alpha only see a tiny part of the total light that is produced, since most of the Lyman-alpha photons are destroyed by interaction with the interstellar clouds of gas and dust. This effect is dramatically more significant for Lyman-alpha than for H-alpha light. As a result, many galaxies, a proportion as high as 90%, go unseen by these surveys. “If there are ten galaxies seen, there could be a hundred there,” Hayes said.

Different observational methods, targeting the light emitted at different wavelengths, will always lead to a view of the Universe that is only partially complete. The results of this survey issue a stark warning for cosmologists, as the strong Lyman-alpha signature becomes increasingly relied upon in examining the very first galaxies to form in the history of the Universe. “Now that we know how much light we’ve been missing, we can start to create far more accurate representations of the cosmos, understanding better how quickly stars have formed at different times in the life of the Universe,” said co-author Miguel Mas-Hesse.

The breakthrough was made possible thanks to the unique camera used. HAWK-I, which saw first light in 2007, is a state-of-the-art instrument. “There are only a few other cameras with a wider field of view than HAWK-I, and they are on telescopes less than half the size of the VLT. So only VLT/HAWK-I, really, is capable of efficiently finding galaxies this faint at these distances,” said team member Daniel Schaerer.

Source: ESO

Illustration of SpaceX's Dragon spacecraft arriving at the International Space Station. ISS astronauts will command Dragon via the SpaceX-developed communications hardware recently installed aboard the ISS. Credit: NASA

SpaceX announced today that a combined team of NASA and SpaceX personal had activated communications hardware aboard the International Space Station that will be crucial for enabling the docking of the Dragon unmanned cargo resupply vehicle being developed by SpaceX.

Start up of the new Ultra High Frequency (UHF) Communication Unit will allow ISS crewmembers to monitor and command approaching or departing Dragon spacecraft during cargo delivery missions to the massive 800,000 pound orbiting laboratory.

The communications hardware was delivered to the ISS aboard the STS 129 mission which blasted off in November 2009. The on-orbit checkout began in January 2010, when astronaut Jeff Williams, ISS Expedition 22 Commander, worked with ground-based team members at SpaceX headquarters and ISS mission control in Houston to power-up and check out the new system.

Astronaut Jeff Williams, Expedition 22 Commander, aboard the International Space Station with the SpaceX-developed controller for the Dragon spacecraft communications system. Credit: NASA

An additional series of tests was performed in March by SpaceX and NASA Houston using the new system to send communications between the ISS and the NASA Dryden ground station. This provided a baseline of the radio frequency performance and confirmed the first set of antennas performed as expected and is ready for mission operations.

The tests employed live video and telemetry links from the ISS to verify the hardware's functionality, broadcast and reception signal strengths, and the system's stability over long-duration operations.

SpaceX won a $1.6 Billion commercial contract from NASA under the Commercial Orbital Transportation Services (COTS) Program to conduct a minimum of 12 cargo flights aimed at delivering at least 20,000 kg of cargo to the ISS using the Dragon spacecraft. The first commercial resupply flights are set to start in 2011 after a series of three test flights start around May 2010.

Astronaut Jeff Williams, Expedition 22 Commander (top) aboard the International Space Station, and engineers at SpaceX Mission Control in Hawthorne, California, perform activation and testing of SpaceX's new communications system for operations with upcoming Dragon spacecraft resupply missions to the ISS. Credit: Roger Gilbertson / SpaceX

Dragon is slated to launch atop the SpaceX developed Falcon 9 rocket. Read my earlier story about the successful rocket engine test firing for the inaugural Falcon 9 rocket.

NASA is counting on the Dragon spacecraft to fill the giant cargo resupply void that will be created once the Space Shuttle program is retired later this year. Without a constant and reliable resupply train of food, spare parts and science equipment the ISS cannot fulfill its role as a world class science research facility. The massive orbiting outpost is nearing completion of its assembly phase and is rapidly transitioning to the science research phase for which it was constructed.