Category: Astronomy

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NASA has terminated a contract with the company it hired to design and construct new spacesuits for use with the new Orion spacecraft after determining it made a mistake in evaluating costs. In terminating the contract NASA hopes to avoid litigation. In June, NASA announced it had selected Oceaneering International, Inc. to build the new spacesuits, but Hamilton Sundstrand, the lead contractor that has supplied spacesuits for NASA since the 1960’s filed a formal protest with the Government Accounting Office on the decision, asking NASA to review its reasoning on the contract award. Hamilton Sundstrand disagreed with the way NASA evaluated the costs for their proposal. NASA has now issued a press release saying “corrective action is appropriate,” and they have “determined that a compliance issue requires the termination of the contract” with Oceaneering “for the convenience of the government.” It appears NASA did some bad math, or used questionable processes to make its decision for the contract.

Hamilton Sundstrand claimed it never received adequate information from NASA about why its bid did not win. Also, NASA failed to request a “cost-accounting standards disclosure statement from Oceaneering during its deliberations,” according to a Wall Street Journal article. A government accounting office letter also said that “The agency must re-examine both offers’ cost proposals. To the extent that any irregularities are identified, appropriate re-evaluation must be made.”

The three-phase $745 million contract called for 109 suits, 24 of which will be the lunar suits.

NASA may have start again from scratch and reopen the bidding for the spacesuit contract.
In a statement Friday, Hamilton Sundstrand said its wants “corrective action” and they are concerned that revisions to the proposal may not correct the “significant errors and deficiencies in the procurement we have protested thus far.”

Sources: Wall Street Journal, NASA press release

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Astronomers announced today that a new “minor planet” with an unusual orbit has been found just two billion miles from Earth, closer than Neptune. Using the Sloan Digital Sky Survey, astronomers detected a small, comet-like object called 2006 SQ372, which is likely made of rock and ice. However, its orbit never brings it close enough to the sun for it to develop a tail. Its unusual orbit is an ellipse that is four times longer than it is wide, said University of Washington astronomer Andrew Becker, who led the discovery team. The only known object with a comparable orbit is Sedna — the distant, Pluto-like dwarf planet discovered in 2003. But 2006 SQ372’s orbit takes it more than one-and-a-half times further from the Sun, and its orbital period is nearly twice as long.

2006 SQ372 is beginning the return leg of a 22,500-year journey that will take it to a distance of 150 billion miles, nearly 1,600 times the distance from the Earth to the Sun. Scientists believe the object is only 50-100 kilometers (30-60 miles) across.

Click here for an animation showing the detection of SQ372 by SDSS.

Becker’s team was actually using the SDSS to look for supernova explosions billions of light-years away to measure the expansion of the universe. “If you can find things that explode, you can also find things that move, but you need different tools to look for them,” said team member Lynne Jones, also of the University of Washington. The only objects close enough to change position noticeably from one night to the next are in our own solar system, Jones explained.

The SDSS-II supernova survey scanned the same long stripe of sky, an area 1,000 times larger than the full moon, every clear night in the fall of 2005, 2006, and 2007.

SQ372 was first discovered in a series of images taken in 2006 by the SDSS, and were verified from images taken in 2005 and 2007.

The researcher team is trying to understand how the object acquired its unusual orbit. “It could have formed, like Pluto, in the belt of icy debris beyond Neptune, then been kicked to large distance by a gravitational encounter with Neptune or Uranus,” said UW graduate student Nathan Kaib. “However, we think it is more probable that SQ372 comes from the inner edge of the Oort Cloud.”

Even at its most distant turning point, 2006 SQ372 will be ten times closer to the Sun than the supposed main body of the Oort Cloud, said Kaib. “The existence of an ‘inner’ Oort cloud has been theoretically predicted for many years, but SQ372 and perhaps Sedna are the first objects we have found that seem to originate there. It’s exciting that we are beginning to verify these predictions.”

Becker noted that 2006 SQ372 was bright enough to find with the SDSS only because it is near its closest approach to the Sun, and that the SDSS-II supernova survey observed less than one percent of the sky.

“There are bound to be many more objects like this waiting to be discovered by the next generation of surveys, which will search to fainter levels and cover more area,” said Becker. “In a decade, we should know a lot more about this population than we do now.”

“One of our goals,” said Kaib, “is to understand the origin of comets, which are among the most spectacular celestial events. But the deeper goal is to look back into the early history of our solar system and piece together what was happening when the planets formed.”

The discovery of 2006 SQ372 was announced today in Chicago, at an international symposium about the Sloan Digital Sky Survey. A paper describing the discovery technique and the properties of 2006 SQ372 is being prepared for submission to The Astrophysical Journal.

News Source: SDSS press release

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Last week, we posted the image above as part of our “Where In The Universe” challenge, where we test our readers’ visual knowledge of our universe. This incredible and unusual Hubble image of object N44F, known as the “Celestial Geode” is a gas cavity carved by the stellar wind and intense ultraviolet radiation from a hot young star. Readers were fascinated by the object and wanted to know more. One of our regular readers, Jorge, asked this question about N44F: “Why is it that we see the back “wall” of the bubble, we see the side walls, but we don’t see the front wall?” I wasn’t able to answer that question, so I sought out one of the astronomers responsible for this image, Dr. You-Hua Chu, professor at the University of Illinois, Urbana-Champaign. Not only did Dr. Chu provide wonderful information about the image, but one of her former students, Dr. Rosie Chen provided Universe Today with an exclusive Spitzer Space Telescope image of the Celestial Geode that has never been published before on the internet.

Dr. Chu explained in more detail what we see in the Hubble image. “This picture shows a cluster of stars that were formed recently, maybe about a million years ago,” she said. “The entire geode was a dense ball of gas and dust. It collapsed under its own gravity to form the cluster of stars.”

Once some massive stars were formed, there was enough UV radiation to ionize the remaining gas, and the stellar wind blows the gas outward. “Depending on how much material exists in each direction,” said Dr. Chu, “an expanding blister may form in the direction with low densities, or a stalled wall is formed in the direction with high densities.”

In response to the question about why we don’t see the front wall of the bubble, Dr. Chu compared the Celestial Geode to a store’s display case. The front wall is so thin, it is as transparent as glass. “You might ask how come we are so lucky to be peering through the thinnest wall of this geode,” said Dr. Chu. “Well, if we were looking at the geode in directions where thick walls exist, we wouldn’t be able to see the inside.”

Dr. Chu said the walls are like a balloon with uneven thickness. The thinnest part will be inflated most and become transparent.

“The interesting thing about this geode is that along its dense wall there are dust pillars sticking out and young stars are being formed at the tips of these pillars. We have obtained Spitzer Space Telescope images of this region and find IR (infrared) sources at the tips of the pillars and the spectral properties of these IR sources suggest that they contain young stars that are still enshrouded in dust.” And here is the Spitzer color composite image, provided by Dr. Rosie Chen, a researcher at the University of Virginia, and created by Dr. Adeline Caulet:

Both Drs. Chu and Chen warned that the Spitzer image may be a bit of a disappointment after seeing the Hubble image. “As you can see the HST images show clearly the detail structure while the Spitzer image is more fuzzy,” said Dr. Chen. “This is because HST’s resolution is over 10 times better than Spitzer.”

When I asked Dr. Chu about how the Hubble image was obtained, she said it was somewhat an accident that this particular part of N44 was imaged. “I proposed to Hubble to observe the superbubble N44 because it had X-ray emissions and I wanted to use high-resolution images to search for supernova remnant shocks,” she said. “The observation was made, but not properly made, so I requested a make-up observation at a slightly different location in N44 to allow an arbitrary roll angle of the space craft.” The Celestial Geode was at the new central position. Dr. Chu said she chose that position because she had always been interested to see what was going on in the ionized gas region, but didn’t have a convincing excuse to propose an observation. “You can say that I took advantage of the make-up observation to sneak in this object,” she said.

In researching this article, I noticed Dr. Chu’s name associated with many outstanding astronomical images. I told her she must be a busy astronomer. “I have to say that I am a lucky astronomer,” she said. “I try to pursue truth and beauty at the same time.”

Chu and Chen’s paper on N44: “Chen, C.-H.R., and Chu, Y.-H. Gruendl, R.A., Gordon, K.D., and Heitsch, F., “Spitzer View of Young Massive Stars in the LMC HII Complex N44,” 2008, ApJ, submitted.”

Since Universe Today’s Ian O’Neill first introduced the idea of Google Earth’s 4D Ionosphere tool, it set my mind to wondering – wondering if the ionospheric changes caused by a meteor shower could be distinguished and used by those armed with a little knowledge and the program. That was months ago. Why wait so long before telling what I’ve discovered? Because any type of investigation of this sort requires a long history of scientific method based controls, lots of research, worldwide observations and… a few meteor showers.

First, let’s talk very briefly and simply about Earth’s ionosphere – your essential last frontier before space. The ionosphere is named for the ions mainly created by energetic particles from the Sun and space itself. These ions create an electrical layer that reflects radio waves and are arranged in layers. New ions are created during bombardment and older ones decay when faced with free electrons. This is a control. The balance of the amount of ionization seen at any given time through any given equipment – and dependent of solar activity, time of day, season and even height.

The F (F1 and F2) layers of the ionosphere are the highest and also the one most likely to be affected by solar circumstances. During daylight hours, F and F1 becomes more highly ionized and go down deeper to the different sky chemistry of the F2 zone. At night, there’s only one strong F layer and it fades as night progresses. Below this is the E layer which is totally unpredictable and just disappears at night. Closest to the Earth is the D layer – which forms during sunlight exposure and dissipates during night. These are all also control models and easily seen with the Google Ionosphere tool. Of course, there are always totally unpredictable things which can occur, but take into consideration that I am creating these control models while monitoring solar activity, the auroral oval and even the terrestrial weather patterns to a certain degree.

Thanks to the magic of the Internet, over the last several months I have been able to chat live with observers around the world as meteor showers have occurred in their locations and been able to compare what they can visually confirm with what I can monitor using the GE 4D Ionosphere tool. Sometimes the results wouldn’t be so great and other times it would be downright amazing. The key to understanding the whole thing is comparing the control samples and a whole lot of work. But, before we get into what it takes, I wanted hard scientific proof that meteor showers really do impact the ionosphere, so I went looking for studies.

According the McNeil (et al): “A comprehensive model of the effect of a major meteor storm on Earth’s ionosphere is presented. The model includes meteor stream mass distributions based on visual magnitude observations, a differential ablation model of major meteoric metals, Fe and Mg, and state-of-the-art modeling of the chemistry and transport of meteoric metal atoms and ions subsequent to deposition. Particular attention is paid to the possibility of direct ionic deposition of metallic species. The model is validated by calculating the effect of annual meteor showers on the background metal atom and ion abundances. A metallic ion density increase of up to 1 order of magnitude is observed, in agreement with in situ measurements during showers. The model is exercised for a hypothetical Leonid meteor storm of the magnitude reported in 1966. The model predicts the formation of a layer of metal ions in the ionospheric E region that reaches peak densities of around 1 x 105 cm-3, corresponding to a 2 order of magnitude increase of the quiescent nighttime E region density. Although sporadic E layers reaching or exceeding this density are relatively common, the effect is different in that it persists on the order of days and would be observed over nearly one-half the globe. The model predictions are consistent with the available 1966 Leonid storm data. In particular, the observation of enhanced, predawn sporadic E activity points to efficient collisional ionization of meteoric metals, as assumed in the model.”

Now let’s talk about what happens when meteors pass through the ionosphere, shall we? Down here on the ground, we “Oooh and Aaaah” over the pretty shooting star, but up there a process called ablation is beginning – that meteoroid particle is heating up and atoms are boiling off. Depending on energy and collision with an air molecule, these ablated meteor atoms are ionizing – freeing an electron and producing a positively charged ion and negatively charged electron. The infant ions begin to cool after they’ve been slammed about 10 times, which takes between a fraction of a millisecond at 80 km and as long as one millisecond at 110 km (according to Jones,1995). During this transition phase, the plasma density right around the meteoroid might take a big jump in structure which produces a large column or trail of enhanced ionization. Studies have shown these columns open up in a “flower-like” pattern and are similar to that which occurs near aurora (Farley and Balsley). These enhanced ionization areas can be miles across, but the free electrons and gas recombine very quickly. This means watching widespread ionosphere models for sporadic activity isn’t very productive – but when a large scale, predictable meteor shower occurs, things are different.

According to Danielis (et al): “More than 40 rocket flights through the main meteoric ionization layer, which peaks near 95 km, have sampled the meteoric metallic ion concentrations. Five of these flights were conducted during or near the peak times of a meteor shower. In each of the latter studies the observed meteoric ion concentrations were assumed to be a consequence of the shower. These measurements were not complemented by baseline observations made for similar ionospheric conditions immediately before the shower and no rigorous quantitative comparisons were made using average non-shower distributions. In order to further investigate the impact of the shower on the ionosphere, all published ion concentration altitude profiles obtained from sounding rockets in the meteoric ionization regime have been scanned to develop a digital data base of meteoric ion concentrations. These data are used to provide the first empirical altitude profile of the metallic ions. The average observed Mg+ concentrations are lower than those yielded by the most comprehensive model to date (McNeil et al., 1996). This compiled ensemble of data provides supporting evidence that meteor showers do have a significant impact on the average ionosphere composition. Although there is much variability in the observed meteoric layers, the peaks in the total metallic ion concentrations at mid-latitudes, on the dayside, observed during meteor showers had concentrations comparable to, or exceeding, the highest concentrations measured in the same altitude regions during non-shower periods.”

Bottom line… Can Google 4D Ionosphere spot major meteor shower activity or not? Here’s a few things to remember this before you try it. Each time you use the ionosphere tool you must visit the Communication Alert and Prediction System (CAPS) website and get the latest information to plug in. At the same time, use the SPIDR (Space Physics Interactive Data Resource) page to make sure of your control circumstances. Now, you’re ready to go! Without overloading this report with all my control images over the last few months (and please forgive the fact that I’m not a master at manipulating images) let me show you what I have…

What you’re seeing here is a compilation of the Google 4D Ionosphere over basically North America during the time frame of August 11 beginning with twilight on the east coast and ending on August 12 at west coast dawn. This is a timeline of what occurred overnight during the 2008 Perseid Meteor Shower peak with visual meteor activity being confirmed as well. When you see blue, you are looking at tolerably good ionosphere – good for radio waves, low density, sunlight, etc. Bright red is high density not conducive to much of anything – like radio wave propagation. That’s what happens at night. So what’s black? Those are the “hot spots” – intense areas of ionization. They can occur randomly, they can be assisted by auroral activity – and apparently they can be traced to meteor shower activity.

Is this proof positive that the GE 4D Ionosphere is a way to watch meteor showers when nights are cloudy? If you remember to take all variables into account, refresh and check all your data and to exercise scientific control models, there’s no reason at all why amateur studies at home cannot provide at very least amusement on our parts. Google Earth 4D Ionosphere is endorsed by NASA and used by pilots, ham radio operators, earth scientists and even soldiers… why not amateur astronomers, too?

I am…

Disclaimer: This article was written and researched out of curiosity by Tammy Plotner and does not reflect the findings, research or applications of the sources stated within it. In other words, NASA doesn’t say you can use it to watch meteor showers and neither does Google – but no one says we can’t experiment with it! The author welcomes additional information, criticisms and comments…

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We humans like to think we’re special, but astronomically speaking we’ve been shot down quite severely and humbly put in our place. We’re not at the center of our solar system, nowhere near the center of our galaxy and certainly not at the center of the universe. But now comes great news for the human psyche from scientists trying to explain solar system formation. As far as solar systems go, we have thought ours was just average and that all solar systems were like ours. But in looking at the 300 plus extrasolar planets that have been discovered and the systems they are in, none so far are anything like our home solar system. In fact, say scientists at Northwestern University, we may be special after all. In a study using computer simulations (this is the week for computer simulations, see here and here), researchers ran more than a hundred simulations, and the results show that the average planetary system’s origin was full of violence and drama but that the formation of something like our solar system required conditions to be “just right” and quite special indeed.

The study illustrates that if early conditions had been just slightly different, very unpleasant things could have happened — like planets being thrown into the sun or jettisoned into deep space. This was the first simulation to model the formation of planetary systems from beginning to end, starting with the generic disk of gas and dust that is left behind after the formation of the central star and ending with a full planetary system.

Before the first exoplanets were discovered in the early 1990’s we only had our own solar system from which to create a model, and astronomers had no reason to think our solar system unusual.

“But we now know that these other planetary systems don’t look like the solar system at all,” said Frederic A. Rasio, a theoretical astrophysicist and professor of physics and astronomy at Northwestern.
“The shapes of the exoplanets’ orbits are elongated, not nice and circular. Planets are not where we expect them to be. Many giant planets similar to Jupiter, known as ‘hot Jupiters,’ are so close to the star they have orbits of mere days. Clearly we needed to start fresh in explaining planetary formation and this greater variety of planets we now see.”

The simulations suggest that an average planetary system’s origin is extremely dramatic. The gas disk that gives birth to the planets also pushes them mercilessly toward the central star, where they crowd together or are engulfed. Among the growing planets, there is cut-throat competition for gas, a chaotic process that produces a rich variety of planet masses.

Also planets orbiting close to each other can create a slingshot encounter that flings the planets elsewhere in the system; occasionally, one is ejected into deep space. Despite its best efforts to kill its offspring, the gas disk eventually is consumed and dissipates, and a young planetary system emerges.

“Such a turbulent history would seem to leave little room for the sedate solar system, and our simulations show exactly that,” said Rasio. “Conditions must be just right for the solar system to emerge.”

Too massive a gas disk, for example, and planet formation is an anarchic mess, producing “hot Jupiters” and noncircular orbits galore. Too low-mass a disk, and nothing bigger than Neptune — an “ice giant” with only a small amount of gas — will grow.

“We now better understand the process of planet formation and can explain the properties of the strange exoplanets we’ve observed,” said Rasio. “We also know that the solar system is special and understand at some level what makes it special.”

“The solar system had to be born under just the right conditions to become this quiet place we see. The vast majority of other planetary systems didn’t have these special properties at birth and became something very different.”

So, go ahead. Feel special.

Original News Source: Northwestern University

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One of the leading theories for how the universe evolved after the Big Bang is the Cold Dark Matter Theory (CDM). This theory proposes that chilly dark matter moved slowly in the early universe, allowing matter to clump together to form the clusters of galaxies that we see, instead of matter being distributed evenly across the universe. Using the properties of the CDM theory, astronomers recently ran an intensive computer program using one of the world’s most powerful supercomputers to simulate the halo of dark matter that envelopes our galaxy. The simulation revealed dense clumps and streams of the mysterious dark matter lurking within our Milky Way galaxy, including the region of our solar system.

“In previous simulations, this region came out smooth, but now we have enough detail to see clumps of dark matter,” said Piero Madau, professor of astronomy and astrophysics at the University of California, Santa Cruz.

This simulation, detailed in an article in the journal Nature, may help may help scientists figure out what dark matter actually is. So far, it has been detected only through its gravitational effects on stars and galaxies. Another part of the CDM theory says that dark matter consists of weakly interacting massive particles (WIMPs), which can annihilate each other and emit gamma rays when they collide. Gamma rays from dark matter annihilation could be detected by the recently launched Gamma-ray Large Area Space Telescope (GLAST).

“That’s what makes this exciting,” Madau said. “Some of those clumps are so dense they will emit a lot of gamma rays if there is dark matter annihilation, and it might easily be detected by GLAST.”

If so, it would be the first direct detection of WIMPS.

Although the nature of dark matter remains a mystery, it appears to account for about 82 percent of the matter in the universe. The clumps of dark matter created “gravitational well” that draws in ordinary matter, giving rise to galaxies in the centers of dark matter halos.

Using the Jaguar supercomputer at Oak Ridge National Laboratory, the simulation took about one month to run and simulated the distribution of dark matter from for 13.7 billion years – from near the time of the Big Bang until the current epoch. Running on up to 3,000 processors in parallel, the computations used about 1.1 million processor-hours.

Source: PhysOrg