Nancy has been with Universe Today since 2004, and has published over 6,000 articles on space exploration, astronomy, science and technology. She is the author of two books: "Eight Years to the Moon: the History of the Apollo Missions," (2019) which shares the stories of 60 engineers and scientists who worked behind the scenes to make landing on the Moon possible; and "Incredible Stories from Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos" (2016) tells the stories of those who work on NASA's robotic missions to explore the Solar System and beyond.
Follow Nancy on Twitter at https://twitter.com/Nancy_A and and Instagram at and https://www.instagram.com/nancyatkinson_ut/
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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.
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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.
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.”
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.
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?”
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
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
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.”
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.
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: Spitzer/Hubble color composite image of N44F. Credit: 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. Dr. You-Hua Chu
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.”
Artists impression of GLAST in orbit. Credit: NASA
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After a 60-day checkout period, science operations have begun in earnest for GLAST, the Gamma ray Large Area Space Telescope, which is now surveying the gamma-ray sky. Launched on June 11, 2008, the GLAST spacecraft has been undergoing calibrations of the two instruments on board, the LAT (Large Area Telescope) and the GBM (GLAST Burst Monitor) — more details on the instruments in a moment. But during the checkout phase both instruments made significant observations of gamma rays. “Given that these detections were made with just the engineering data observations, the future is full of promise, and we are very excited,” said Dr. Steve Ritz, GLAST Project Scientist in his GLAST blog. At the end of August, there will be a formal release of the first-light images taken by the spacecraft. Also at that time, NASA will rename the observatory. I don’t know about you, but I’m sort of attached to the name “GLAST.” But it will be interesting to find out its new, official name.
In June, LAT detected two extraordinarily bright, flaring sources in space, which scientists believe are very likely supermassive black hole systems at the cores of active galaxies, located far across the universe, but incredibly bright. Additionally, by the end of July, the GBM had detected 12 gamma ray bursts.
“We are thrilled to be detecting gamma-ray bursts so early in the mission. GLAST and the GBM are off to a great start!” said Charles “Chip” Meegan, GBM principal investigator at NASA’s Marshall Space Flight Center, Huntsville, Ala. “The detectors are working well and we’re really pleased with how the instrument is working. That said, we’re using this checkout period to scrutinize the data coming down from the detectors and fine tune flight and ground software and our daily operational processes.” GRBs detected by GLAST. Credit: NASA
The LAT detects gamma rays and is able to make gamma ray images of astronomical objects. The GBM is designed to observe gamma ray bursts, which are sudden, brief flashes of gamma rays that occur about once a day at random positions in the sky. The GBM has such a large field-of-view that it will be able to see bursts from over 2/3 of the sky at one time. The observations made by GBM were verified by the Swift Telescope, another space telescope that can swiftly skew around to view a gamma ray burst.
NASA has a tradition of renaming spacecraft after a successful launch, and with GLAST they decided to wait until the “first light” images are released. Any guesses on what the new name will be?
The Baghdad and Cairo Sulci, sources of geysers on Enceladus. Image: NASA/JPL/Space Science Institute
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Cassini scientists have been “bee-busy” poring over the images from the August 11 flyby of Saturn’s geyser-spewing moon Enceladus, says Carolyn Porco, the lead for the imaging team. And quickly, they have found exactly what they were looking for: Cassini has pinpointed precisely where the icy jets erupt from the moon’s geologically active moon surface. Enceladus. “This is the mother lode for us,” said Porco, “a place that may ultimately reveal just exactly what kind of environment — habitable or not — we have within this tortured little moon.”
New carefully targeted pictures reveal exquisite details in the prominent south polar “tiger stripe” fractures from which the jets emanate. The images show the fractures are about 300 meters (980 feet) deep, with V-shaped inner walls. The outer flanks of some of the fractures show extensive deposits of fine material. Finely fractured terrain littered with blocks of ice tens of meters in size and larger (the size of small houses) surround the fractures. Damscus Sulcus, another source of geysers on Enceladus. Image: NASA/JPL/Space Science Institute
One highly anticipated result of this flyby was finding the location within the fractures from which the jets blast icy particles, water vapor and trace organics into space. Scientists are now studying the nature and intensity of this process on Enceladus, and its effects on surrounding terrain. This information, coupled with observations by Cassini’s other instruments, may answer the question of whether reservoirs of liquid water exist beneath the surface.
The high-resolution images were acquired as Cassini sped past the icy moon at 64,000 kilometers per hour (40,000 miles per hour). A special technique, dubbed “skeet shooting” by the imaging team, was developed to cancel out the high speed of the moon relative to Cassini and obtain the ultra-sharp views.
“Knowing exactly where to point, at just the right time, was critical to this event,” said Paul Helfenstein, Cassini imaging team associate at Cornell University, Ithaca, NY., who developed and used the skeet-shoot technique to design the image sequence. “The challenge is equivalent to trying to capture a sharp, unsmeared picture of a distant roadside billboard with a telephoto lens out the window of a speeding car.” False color mosaic shows the south pole region where the jets emanate. Image: NASA/JPL/Space Science Institute
The tiger stripes, officially called sulci, have been named for characters and places from “The Arabian Nights.” The yellow circles on the images indicate the sources of the jets.
Helfenstein said that from Cassini’s point of view, “Enceladus was streaking across the sky so quickly that the spacecraft had no hope of tracking any feature on its surface. Our best option was to point the spacecraft far ahead of Enceladus, spin the spacecraft and camera as fast as possible in the direction of Enceladus’ predicted path, and let Enceladus overtake us at a time when we could match its motion across the sky, snapping images along the way.”
For scientists, having the combination of high-resolution snapshots and broader images showing the whole region is critical for understanding what may be powering the activity on Enceladus.
“There appears to have been extensive fallout of icy particles to the ground, along some of the fractures, even in areas that lie between two jet source locations, though any immediate effects of presently active jets are subtle,” said Porco.
Imaging scientists suggest that once warm vapor rises from underground to the cold surface through narrow channels, the icy particles may condense and seal off an active vent. New jets may then appear elsewhere along the same fracture.
“For the first time, we are beginning to understand how freshly erupted surface deposits differ from older deposits,” said Helfenstein, an icy moons expert. “Over geologic time, the eruptions have clearly moved up and down the lengths of the tiger stripes.”
