Posted on by Nancy Atkinson

“Where In the Universe” Challenge #17

It’s Wednesday, so it’s time for another “Where In The Universe” Challenge. Take a look at the image above and try to determine where in the universe this image was taken. Give yourself extra points if you can name the spacecraft responsible for taking this image. As always, no peeking below for the before you make your guess. Our readers have been having a blast with this challenge, and we hope this one will evoke more eruptions of cheers and enjoyment.

This is a small volcano island here on Earth, found in the Aleutian Islands. But tiny Kasatochi Volcano created a big mess in recently by spewing ash and sulfur dioxide over the surrounding area. The volcano erupted with little warning on August 7, 2008. No one was hurt, but two biologists were evacuated from the island just hours before the eruption. According to the Associated Press, the ash forced Alaska Airlines to cancel 44 flights between Alaska, Canada, and the continental United States. Until the eruption, the steep-sided volcano harbored a small lake inside its 314-meter (1000-foot) summit, and vegetation (red in this image) covered the slopes. Cliffs along the shoreline may be the result of erosion from heavy surf, visible as a white fringe around the island. Kasatochi had not erupted in at least 200 years.

This image, composed of near-infrared, red, and green wavelengths of light, was acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite in 2003.

Here’s a link to some images showing Kasatochi during the eruption.

NASA image and caption by Robert Simmon, based on data from the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team and found on the NASA Earth Observatory website.

Posted on by Nancy Atkinson

NASA to Install “Shock Absorbers” to Mitigate Thrust Oscillation

Thrust Oscillation Actuators. Credit: NASA

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NASA will add a system engineers equated to shock absorbers to Ares 1 rockets to reduce significant vibrations that could shake the Orion spacecraft and astronaut crews during early stages of the flight. Earlier, engineers had determined that at about 115 seconds into the flight, the Ares rocket would vibrate for about 5 seconds, enough to potentially make it difficult for crews to read console displays. To mitigate what’s called thrust oscillation, engineers have proposed an active tuned mass absorber that would detect the frequency and amplitude of the thrust oscillation with accelerometers and internal pressure sensors, and use battery-powered motors to move spring mounted weights up and down to damp the vibration out. A spring-and-damper ring will separate the first and second stages of the rocket, and 16 actuators that act like shock absorbers will be added to the bell-shaped aft skirt at the bottom of the rocket.

Engineers are also looking to use a passive “compliance structure” which is a spring-loaded ring that would detune the stack by softening the interface between the first and upper stages while preserving lateral stability in the Ares 1 design concept.

This concept is expected to reduce the G-forces on the astronauts from about 5 G’s to .25 G’s.
Computer modeling and early design analyses showed the Ares 1 rocket would shake near 105-115 seconds into the flight after liftoff, subjecting the Orion spacecraft and astronauts onboard to high G forces for only about 5 seconds. But NASA engineers were concerned that astronauts could be injured or critical systems could be damaged during that time of the flight.

The thrust oscillation occurs as solid fuel in the first stage depletes, leaving a long, empty shell that takes on the characteristics of an organ pipe, resonating, at frequencies between 12 and 14 hertz. The second stage of the rocket and the Orion spacecraft atop it will naturally dampen the resulting pressure pulses, which essentially would jackhammer the astronauts and make it difficult for them to read console displays and respond.

Source: NASA news conference.

Posted on by Nancy Atkinson

More Frost on Mars Phoenix Lander

Phoenix Telltale. credit: NASA/JPL/Caltech/Uof Arizona

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More early morning frost is showing up on the Phoenix spacecraft. The Surface Stereo Imager (SSI) took several pictures of the “Telltale” on the Phoenix Mars Lander, the device used to measure wind velocities at the landing site on Mars and created a movie of bright specks of frost accumulating on the mirror of the Telltale. The movie was created from a series of images taken by the Surface Stereo Imager (SSI)between 12:54 a.m. and 2:34 a.m. during the 80th Martian day, or sol, of the mission (Aug. 15, 2008 here on Earth). Sorry, we couldn’t load the movie on this page, the file was too big. But follow this link to see it — the frost is very cool (pun intended).

Phoenix’s SSI took these images through a blue filter (450 nanometer wavelength) that is used primarily for viewing items on the spacecraft rather than the workspace or horizon. In order to increase the number of frames, the size of the individual images downlinked from the spacecraft has been reduced. These have been shown superimposed upon a full image of the telltale from Sol 13 for context. The frost on the mirror sparkles in low-angle light from the sun, which is barely above the horizon at this hour.

Via Twitter, the Phoenix spacecraft said not to worry, this type of early morning frost is not a concern for the operation of the spacecraft.
The Telltale experiment is a passive instrument that provides information about winds at the landing site. It consists of a lightweight Kapton tube hanging in Kevlar fibers that will deflect as a result of wind forces. Images of the Telltale obtained by the onboard camera (SSI) using long exposure times provide information on the deflection and dynamics that can be related to wind velocities and turbulence.

During the early-morning period when these images were taken the wind was blowing steadily at about 5 meters per second (about 11 miles per hour) from the northeast, as indicated by the telltale.

The telltale is about 10 centimeters (4 inches) tall and the total mass of the active part is about 10 mg. The experiment was built by the University of Aarhus, Denmark.

Phoenix weather summary from Sol 63
Phoenix weather summary from Sol 63

Here’s some info on the weather on Mars, although Sol 63 is the latest available from the Mars Weather Station on Phoenix. To learn more about the Weather Station, follow this link.

Posted on by Nancy Atkinson

Flat Nano-Thrusters Could Save Weight and Fuel for Spacecraft

Spaceship of the future? Credit: 3Dtotal.com

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Currently, launching 1 pound (.5 kilogram) of payload to space costs about $5,000 USD, so every little bit helps if engineers can cut down on the weight of the spacecraft. Scientists from the University of Michigan have patented their ideas for cutting down the size and weight of the thrusters used in space to maneuver and control the spacecraft. Usually these thrusters are fairly big; they can be as big as a refrigerator. But the new thrusters, called nano-thrusters, could be made into flat, low weight sheets and mounted on the sides of spacecraft. The new type of thrusters would save weight and fuel, while having a longer life as well.

Conventional ion thrusters work by accelerating gas ions to generate force in the opposite direction. But, they waste gas and are limited in lifetime because the accelerated ions damage the engine.

But, according to a report in New Scientist, the new nano-thrusters, developed by Brian Gilchrist and colleagues at the University of Michigan in Ann Arbor, US, avoid these problems.

Each consists of a small chamber of fluid with electrodes inside and a vent at the top. Above that vent more electrodes generate a powerful electric field. The fluid contains nanoparticles just tens of nanometres across that are ionized by electrodes in the chamber. Those charged ions are accelerated by the electric field and ejected from the vent, producing thrust.

These nanothrusters can be used in large numbers on flat panels. To control the spacecraft efficiently, they would probably have to cover large areas of spacecraft. But in the drag-free space environment, it be just like having a second skin on the spacecraft. And they would be much more light-weight than conventional thrusters, and would help cut the costs of launching vehicles to space.

Read the U of M’s patent here.

Source: New Scientist

Posted on by Nancy Atkinson

The Battle for the Space Vote

Barack Obama and John McCain

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Remember a few months ago when “space” seemed to be a non-issue for the candidates in this year’s US presidential election? But now space seems to be a hot topic. John McCain was in Florida today where he met with 20 leaders from the space industry for a roundtable discussion, and Barack Obama was in Florida last week, to stump for votes. Perhaps both candidates are recalling the 2000 presidential election that hinged on the Florida vote. Hanging chads aside, an important issue in Florida these days is the projected job losses that will be incurred in the gap after the space shuttle is retired in 2010 and before the Constellation program makes its first flights in about 2015, and both candidates have met with members of NASA’s workforce and other NASA officials to discuss this issue. Also, both McCain and Obama recently updated their positions on their space-related agendas on their websites, with both devoting quite a bit of “space” to space.

If you’re still undecided, or haven’t seen the candidate’s latest views on space, take a look at Barack Obama’s position paper on space and John McCain’s space policy statement. If that’s too much reading for you, the folks at Florida Today.com have outlined the major points of each candidate’s space policies:
• Major points of Obama’s space policy:

1. Re-enacting the National Aeronautics and Space Council to oversee and coordinate the civilian, commercial and military space programs and report to the president.
2. Closing the gap between the retirement of the Space Shuttle and the introduction of its successor through adding another Shuttle flight, accelerating the development of the next generation vehicle, and working with the industry to retain our workforce and technical capabilities.
3. Completing and enhancing the International Space Station so it can host the innovative scientific and technological research projects it was intended to facilitate.
4. Embracing human and robotic space exploration with a goal of sending human missions to the Moon by 2020, as a precursor in an orderly progression to missions to more distant destinations, including Mars.
5. Emphasizing NASA’s research function to study climate change and advance aeronautics research.
6. Expanding public/private partnerships to develop cutting-edge technologies.
7. Inspiring the next generation through expanded education programs.

Major points of McCain’s space policy:

1. Ensure that space exploration is top priority and that the U.S. remains a leader.
2. Commit to funding the NASA Constellation program to ensure it has the resources it needs to begin a new era of human space exploration.
3. Review and explore all options to ensure U.S. access to space by minimizing the gap between the termination of the Space Shuttle and the availability of its replacement vehicle.
4. Ensure the national space workforce is maintained and fully utilized; Complete construction of the ISS National Laboratory.
5. Seek to maximize the research capability and commercialization possibilities of the ISS National Laboratory.
6. Maintain infrastructure investments in Earth-monitoring satellites and support systems.
a. Seek to maintain the nation’s space infrastructure.
7. Prevent wasteful earmarks from diverting precious resources from critical scientific research.
8. Ensure adequate investments in aeronautics research.

News Sources: Florida Today

Posted on by Nancy Atkinson

NASA Cancels Spacesuit Contract to Avoid Litigation

Proposed spacesuits from Oceaneering, Inc. Image: NASA

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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

Posted on by Nancy Atkinson

Astronomers Find a New “Minor Planet” near Neptune

Orbit of solar system object SQ372 (blue) compared with the orbits of Neptune Pluto and Sedna (white, green, red). Credit: N. Kaib.

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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

Posted on by Nancy Atkinson

Dark Matter is Missing From Cosmic Voids

Map of distribution of galaxies. Credit: M. Blanton and the SDSS.

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Cosmic voids really are devoid of matter. Astronomers have found that even the pervasive ‘dark matter’ which accounts for about 80% of the mass of the universe is not present in these voids, which are areas of vast emptiness in space that can be tens of millions of light-years across. “Astronomers have wondered for a quarter-century whether these voids were ‘too big’ or ‘too empty’ to be explained by gravity alone,” said University of Chicago researcher Jeremy Tinker, who led the new study using data from the Sloan Digital Sky Survey II (SDSS-II). “Our analysis shows that the voids in these surveys are exactly as big and as empty as predicted by the ‘standard’ theory of the universe.”

The largest 3-dimensional maps of the universe show that galaxies lie in filamentary superclusters interlaced by cosmic voids that contain few or no bright galaxies. Researchers using SDSS-II and the
Two-Degree Field Galaxy Redshift Survey (2dFGRS) have concluded that these voids are also missing the “halos” of invisible dark matter that bright galaxies reside in.

A central element of the standard cosmological theory is cold dark matter, which exerts gravity but does not emit light. Dark matter is smoothly distributed in the early universe, but over time gravity pulls it into filaments and clumps and empties out the spaces between them. Galaxies form when hydrogen and helium gas falls into collapsed dark matter clumps, referred to as “halos,” where it can form luminous stars.

But astronomers were not sure if the areas that are devoid of galaxies were also devoid of dark matter, or if the dark matter was there, but for some reason stars just didn’t form in these voids.
The research team used bright galaxies to trace the structure of dark matter and compared it with computer simulations to predict the number and sizes of voids.
Princeton University graduate student Charlie Conroy measured the sizes of voids in the SDSS-II maps. “When we used galaxies brighter than the Milky Way to trace structure, the biggest empty voids we found were about 75 million light years across,” said Conroy. “And the predictions from the simulations were bang-on.”

The sizes of voids are ultimately set, Conroy explained, by the small variations in the primordial distribution of dark matter, and by the amount of time that gravity has had to grow these small variationsinto large structures.

The agreement between the simulations and the measurements holds for both red (old) and blue (new) galaxies, said Tinker. “Halos of a given mass seem to form similar galaxies, both in numbers of stars and in the ages of those stars, regardless of where the halos live.”

Tinker presented his findings today at an international symposium in Chicago, titled “The Sloan Digital Sky Survey: Asteroids to Cosmology.” A paper detailing the analysis will appear in the September 1 edition of The Astrophysical Journal, with the title “Void Statistics in Large Galaxy Redshift Surveys: Does Halo Occupation of Field Galaxies Depend on Environment?”

News Source: SDSS and The Ohio State University

Posted on by Nancy Atkinson

Phoenix Camera Snaps Frost on Mars

Morning Frost on Mars. Image credit: NASA/JPL-Caltech/University of Arizona/Texas A&M University

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It’s getting a little nippy at night on Mars. The Phoenix lander’s Surface Stereo Imager took this image at 6 a.m. on Sol 79 (August 14, 2008 here on Earth), and a thin layer of water frost is visible on the ground around the landing area. From subsequent images, the frost begins to disappear shortly after this image was taken as the sun rises on the Phoenix landing site.

The sun was about 22 degrees above the horizon when the image was taken, enhancing the detail of the polygons, troughs and rocks around the landing site.

This view is looking east southeast with the lander’s eastern solar panel visible in the bottom lefthand corner of the image. The rock in the foreground is informally named “Quadlings” and the rock near center is informally called “Winkies.”

This false color image has been enhanced to show color variations.

Earlier images taken in June, and put together here in sequence to form a movie, appears to show frost forming on Phoenix’s own legs.

What appears to be frost appears on Phoenix's legs. Credit: Wanderingspace.net
What appears to be frost appears on Phoenix's legs. Credit: Wanderingspace.net

But this isn’t the first time that frost has been imaged on Mars. The Viking lander took the picture below in 1979 of its landing site at Utopia Planetia showing ample amounts of frost on the surface.

frost on Mars in a photograph taken by the Viking 2 lander on May 18, 1979. NASA/JPL
frost on Mars in a photograph taken by the Viking 2 lander on May 18, 1979. NASA/JPL

In other news, the Phoenix lander also announced on Twitter that it has opened another TEGA oven door in preparation for receiving another sample of Martian soil to “bake and sniff.”

New Source: Phoenix Image Gallery, Wanderingspace.net

Posted on by Nancy Atkinson

Milky Way Creates a Mess by Stealing Stars from Nearby Galaxies

Model of a our galaxy showing trails of stars torn from disrupted satellite galaxies. Credit: K. Johnston, J. Bullock

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The halo of stars that envelops the outer Milky Way galaxy is like a “jumble of pasta” said one researcher, describing criss-crossed patterns of stellar streams revealed in new data from the Sloan Digital Sky Survey (SDSS). These stars appear to have been ripped away from the dwarf galaxies that are companions to our own galaxy, creating messy, spaghetti-like streams of stars in the outer edge of the Milky Way. The SEGUE (Sloan Extension for Galactic Understanding and Exploration) of the Sloan Survey is mapping the structure and stellar makeup of the Milky Way Galaxy and has found numerous new small streams of stars mixed and tangled among larger streams that had been mapped out over the last decade. It appears the Milky Way’s thievery is creating quite a mess.

While the center of galaxy is quite orderly, the outer Milky Way is a cluttered mess. Kathryn Johnston from Columbia University explained how dwarf galaxies that pass close to the Milky Way can be stretched by gravitational tides into spaghetti-like strands, which wind around the Galaxy as stars trace out the same orbital paths at different rates.

“In the center of the Galaxy, these stellar strands crowd together and you just see a smooth mix of stars,” said Johnston. “But as you look further away you can start to pick out individual strands, as well as features more akin to pasta shells that come from dwarfs that were on more elongated orbits.” Johnston described the new smaller strands recently detected as “angel hair” that came from smaller dwarf or ones that were destroyed longer ago.

Heidi Newberg of Rensselaer Polytechnic Institute and her thesis student Nathan Cole have been trying to follow some of the larger strands as they weave across the sky. “It’s a big challenge to piece things together,” said Cole, “because the stream from one dwarf galaxy can wrap around the Galaxy and pass through streams of stars ripped from other dwarf galaxies.”

Toward the constellation Virgo, where SDSS images revealed an excess of stars covering a huge area of sky, there are at least two superposed structures, and possibly three or more. The SEGUE velocity measurements can separate systems that overlap in sky maps, Newberg explained. “Part of what we see toward Virgo is a tidal arm of the Sagittarius dwarf galaxy, whose main body lies on the opposite side of the Milky Way, but we don’t know the origin of the other structures. There really aren’t enough pasta varieties to describe all the structures we find.”

“The SDSS has taught us a huge amount about the Milky Way and its neighbors,” said Johnston. “But we’re still just beginning to map the Galaxy in a comprehensive way, and there’s a trove of discoveries out there for the next generation of surveys, including the two new Milky Way surveys that will be carried out in SDSS-III,” the next set of surveys slated for Sloan.

Original News Source: SSDS press release, The Ohio State University