Posted on by Nancy Atkinson

US Astronauts May Have to Leave Space Station in 2012

A Soyuz approaches the ISS. Credit: NASA

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Because of stalled legislation that is needed to allow NASA to pay the Russian Space Agency to ferry US astronauts to the International Space Station on board the Soyuz spacecraft, the US section of the space station may have to go unmanned in at least part of 2012. In an interview with CBS’s Bill Harwood, NASA Administrator Mike Griffin said because of the of the three-year lead time needed to build Soyuz vehicles, contracts must be in place by early 2009. But because of Russia’s invasion of Georgia, Congress is unlikely to extend an exemption that allows money to be paid to Russia for high technology goods. Griffin said the problem is very serious, and new legislation would have to be approved within the next few weeks to prevent an interruption in NASA astronauts being on board the ISS.

With the exemption to the Iran-North Korea-Syria Non-Proliferation Act, NASA has been able to buy Soyuz seats for U.S. and international astronauts. While the exemption doesn’t expire until the end of 2011, Congress must approve an extension now in order for NASA to place contracts with the Russians by early next year.

Griffin said NASA has been working all year on getting the needed legislation passed. Congress has been aware of the need for a renewal of the exemption for quite some time, as Griffin talked about the importance of the exemption in his testimony during budget hearings last winter.

NASA also is counting on using the Soyuz to bridge the five-year gap between the end of shuttle operations in 2010 and the debut of the Constellation program in 2015. In addition, NASA still needs the Russian Soyuz for rescue capability for the ISS.

“Where it stands is right now,” Griffin said of the exemption, “it’s dead stalled. Because there’s no legislation which is going to come out of the Congress, other than the continuing resolution package, before they recess to go home for elections. And so right now, we’re just on dead stop. And of course, the invasion of Georgia didn’t help.”

“So here’s what will happen. The first and most obvious possibility is there won’t be any American or international partners on the space station after Dec. 31 of 2011. That’s a possibility. Another possibility is that we will be told to continue flying shuttle and we would be given extra money to do so, in which case our Ares and Orion could be kept on track and we would no longer have a dependence on Russia.

“A third possibility is we could be told to keep flying shuttle, not be given any extra money, in which case we don’t get Ares and Orion anytime soon and we still have a gap, it’s just further out in time.”

Asked if he has any optimism a waiver can be in place in time to avoid a gap in U.S. space station operations, Griffin said simply, “no.”

“My own guess is at this point we’re going to have some period in 2012 where there’s no American or international partner crew on station, that there’s only the Russians there,” he said. “That period always ends three years from when we have a contract with the Russians. So if we can get through all this by June of next year and have a contract with the Russians, then in the latter part of 2012 we can fly a Soyuz flight and restore things to normal.”

A transcript of the entire interview is available from CBS News here. In the interview, Griffin also talks about the upcoming mission to the Hubble Space Telescope and the recently announced delays for the Constellation Program.

Source: CBS News Space Place

Posted on by Nancy Atkinson

Communicating Via the Cepheid Galactic Internet

Cepheid Variable Star. Credit: Hubble Space Telescope

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If an alien species wanted to communicate with Earthlings, or any other civilization that might be out there, how might they do it? Some have proposed microwaves, neutrinos or lasers, or even moving stars around into patterns. But why wouldn’t aliens just use the internet? The Cepheid Galactic Internet, that is. A group of scientists has proposed that a sufficiently advanced civilization could use Cepheid variable stars as beacons to transmit information throughout the galaxy and beyond. These stars can be seen from long distances and, the scientists say, any technologically advanced civilization would likely observe Cepheid variables as distance markers. The group of physicists and astronomers from Hawaii and California propose that Cepheids and any other regular variable stars should be searched for signs of phase modulation and patterns which could be indicative of intentional signaling.

In their paper, the group of scientists proposes that advanced civilizations hoping to communicate would want to use a form of communication with a high data rate, just as everyone on Earth would prefer broadband for their internet. Microwaves and lasers have problems with resolution and noise, while photons or neutrinos would take an enormous amount of power to send messages long distances. And moving stars around? Well, that sounds pretty difficult if not labor intensive. So how about something akin to a T1 line that is already established? All that would need to be done is to “tickle” the star, as the scientists call it, or tweak the Cepheid, to send a message. The researchers write, “Recently, some authors have driven home the point that it is far more energetically practical for transmitting large amounts of data to place long lasting artifacts in stellar systems to which the ETI (extra terrestrial intelligence) may wish communicate information (their history for example) as intelligent life matures and becomes capable of decoding this ‘Rosetta stone.’”

By “tickling” the star, with the delivery of a relatively small amount of energy via neutrinos or other forms of power pulses at the right time could trigger the Cepheid to a specific variability, and a message could be encoded within that variability.

The researchers admit the civilization attempting this would have to be highly advanced. But if some civilization has in fact created a message and sent it via the Cepheid Galactic Internet, all we have do to is open our inbox.

Who knows, they could be on to something. They’ve even discussed their proposal with Freeman Dyson. “It may be a long shot,” they write, “but should it be correct, the payoff would be immeasurable for humanity. The beauty of this suggestion seems to be simply that the data already exists, and we need only look at the data in a new way.”

Sources: arXiv, On Orbit

Posted on by Nancy Atkinson

Where In The Universe Challenge #19

Here’s another “Where In The Universe” challenge, and in keeping with the Mission:Impossible theme from the previous post, your mission, should you choose to accept, is to identify where in the universe this image was taken. Give yourself extra points if you can name the spacecraft responsible for the image. Does everyone have their watches synchronized and secret decoder image detectors ready? It’s fairly certain this website will not self destruct in five seconds, so take your time looking at the image. As always, no peeking below before you make your guess.

This is an image of a dune field on Mars in Wirtz Crater, and yes, the white material is actually frost on the dunes. It was taken by the HiRISE Camera on the Mars Reconnaissance Orbiter. I came across this image while searching for more evidence of frost on Mars, other than what the Phoenix and Viking Landers had imaged. Just to make sure I wasn’t seeing things, I checked in with Nathan Bridges from JPL and the HiRISE Team about this image. He explains, “The white material is frost, composed of water and/or carbon dioxide. When this image was taken, it was winter in this part of Mars and it gets cold enough for water to condense out of the atmosphere and even for the atmosphere itself to freeze (the atmosphere is made of CO2) The color is approximately what you would see on Mars, but is enhanced to bring out detail.”

This image was taken on January 7, 2007 at about 3:50 in the afternoon, Mars local time, as HiRISE was 254 km (158.7 miles) above Mars’ surface. Wirtz Crater is located at -48 degrees latitude and 334.6 degrees longitude east.

For more information about this image, or to get higher resolution versions of the entire image swath, check out HiRISE’s website.

Posted on by Nancy Atkinson

Asteroid Imposters

Are some asteroid masked of their true identity?

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A frequent plot device in the old “Mission: Impossible” television show was the special masks the IMF team used so they could impersonate anyone. Viewers were often surprised to find out who ended up being an imposter. Similarly, astronomers and planetary scientists are considering that a fair amount of Near Earth Objects (NEOs) aren’t what they appear: they could be comets impersonating asteroids. Paul Abell, from the Planetary Science Institute says between five and ten percent of NEOs could be comets that are being mistaken for asteroids, and Abell is working on ways to make unmasking them a mission that’s possible.

Some NEOs could be dying comets, those that have lost most of the volatile materials that create their characteristic tails. Others could be dormant and might again display comet-like features after colliding with another object, said Abell. He is using NASA’s Infrared Telescope Facility at the Mauna Kea Observatories in Hawaii and the MMT telescope on Mount Hopkins, south of Tucson, Ariz., to uncover observational signatures that separate extinct/dormant comets from near-Earth asteroids.

This is important for a couple of reasons. First, dormant comets in near-Earth space could become supply depots to support future exploration activities with water and other materials. Second, like other NEOs, they could pose a threat to Earth if they are on a collision course with our planet. Third, they can provide data on the composition and early evolution of the solar system because they are thought to contain unmodified remnants of the primordial materials that formed the solar system.
Comet Tempel 1. Credit: NASA/U of Maryland
Unlike rocky asteroids that blast out craters when they slam into Earth, comets are structurally weak and likely to break up as they enter the atmosphere, leading to a heat and shockwave blast that would be much more devastating than the impact from an asteroid of the same size.

Low-activity, near-earth comets flashed onto the planetary-science radar screen in 2001, when NEO 2001 OG108 was discovered by the Lowell Observatory Near Earth Asteroid Search telescope. It had an orbit similar to comets coming in from the Oort Cloud, but had no cometary tail. But in early 2002 when it came closer to the sun, the heat vaporized some of the comet’s ice to create the clouds of dust and gas that make up the comet’s coma and tail. It was then reclassified as a comet.

“That’s what started me on this line of reasoning and scientific investigation,” Abell said.
By combining orbital data with spectra and the albedos (brightness) of these objects, Abell hopes to identify which are low-activity comets and where they are coming from.
“Are all these comets made of the same type of material or are they different?” Abell asked. “If they’re composed of different materials, they may have different spectral signatures, and our preliminary work on Jupiter-family comets and Halley-type comets shows that this may be true. Why is that? Is it something to do with the initial conditions of their formation regions? Or is it due to the different environments in which they spend most of their time?”

“All this is important to understanding their internal makeup, which will give us data on the material composition and evolution of the early solar system,” he added.

Source: PSI Press Release

Posted on by Nancy Atkinson

Astronomers Link Telescopes to Zoom In On Milky Way’s Black Hole

Computer simulation of what a "hot spot" of gas orbiting a black hole would look like in an extremely high-resolution image. Credit: Avery Broderick (CITA) & Avi Loeb (CfA)

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An international team of astronomers has obtained the closest views ever of what is believed to be a super-massive black hole at the center of the Milky Way galaxy. The astronomers linked together radio dishes in Hawaii, Arizona and California to create a virtual telescope more than 2,800 miles across that is capable of seeing details more than 1,000 times finer than the Hubble Space Telescope. The target of the observations was the source known as Sagittarius A* (“A-star”), long thought to mark the position of a black hole whose mass is 4 million times that of the sun.

Using a technique called Very Long Baseline Interferometry (VLBI), the astronomers studied the radio waves coming from Sagittarius A*. In VLBI, signals from multiple astronomy telescopes are combined to create the equivalent of a single giant telescope, as large as the separation between the facilities. As a result, VLBI yields exquisitely sharp resolution.

They detected structure at a tiny angular scale of 37 micro-arcseconds – the equivalent of a baseball seen on the surface of the moon, 240,000 miles distant. These observations are among the highest resolution ever done in astronomy.

“This technique gives us an unmatched view of the region near the Milky Way’s central black hole,” said Sheperd Doeleman of MIT, first author of the study that will be published in the Sept. 4 issue of the journal Nature.

Computer animation illustrating a spinning black hole. Credit: NASA
Computer animation illustrating a spinning black hole. Credit: NASA

Though Sagittarius A* was discovered three decades ago, the new observations for the first time have an angular resolution, or ability to observe small details, that is matched to the size of the black hole “event horizon” — the region inside of which nothing, including light, can ever escape.

With three telescopes, the astronomers could only vaguely determine the shape of the emitting region. Future investigations will help answer the question of what, precisely, they are seeing: a glowing corona around the black hole, an orbiting “hot spot,” or a jet of material. Nevertheless, their result represents the first time that observations have gotten down to the scale of the black hole itself, which has a “Schwarzschild radius” of 10 million miles.

The concept of black holes, objects so dense that their gravitational pull prevents anything including light itself from ever escaping their grasp, has long been hypothesized, but their existence has not yet been proved conclusively. Astronomers study black holes by detecting the light emitted by matter that heats up as it is pulled closer to the event horizon. By measuring the size of this glowing region at the Milky Way center, the new observations have revealed the highest density yet for the concentration of matter at the center of our galaxy, which “is important new evidence supporting the existence of black holes,” said Doeleman.

“This result, which is remarkable in and of itself, also confirms that the 1.3-mm VLBI technique has enormous potential, both for probing the galactic center and for studying other phenomena at similar small scales,” said co-author Jonathan Weintroub.

The team plans to expand their work by developing novel instrumentation to make more sensitive 1.3-mm observations possible. They also hope to develop additional observing stations, which would provide additional baselines (pairings of two telescope facilities at different locations) to enhance the detail in the picture. Future plans also include observations at shorter, 0.85-mm wavelengths; however, such work will be even more challenging for many reasons, including stretching the capabilities of the instrumentation, and the requirement for a coincidence of excellent weather conditions at all sites.

Source: Harvard Smithsonian press release

Posted on by Nancy Atkinson

Understanding the “Superotation” Winds of Venus

Venus observed by Venus Express. Credit: ESA

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Astronomers observing Venus back in the 1960’s discovered that the top level of Venusian cloud layers moved very rapidly, orbiting the planet in only four Earth days, compared to the planet’s own rotation of 243 Earth days. This phenomenon is called the “superotation” of Venus. The winds carrying these clouds travel at 360 km/hr, while winds at the planet’s surface are just a breeze at a few km/hr, and there have been indications that at times there’s no wind on Venus’ surface. This unique characteristics have been perplexing, but new observations carried out with ESA’s Venus Express, in orbit around Venus since April 2006, are offering insights to the planet’s atmosphere. Scientists have been able to determine in detail the global structure of the winds on Venus at the different levels of clouds while, at the same time, observe unexpected changes in the wind speeds, and which will help to interpret this mysterious phenomenon.

Venus is similar to Earth in size, and sometimes is called Earth’s sister planet. Nevertheless, it is quite different in other aspects. It’s slow rotation is also retrograde, or in the opposite direction to that of our planet, i.e. from East to West. It’s dense atmosphere of carbon dioxide with surface pressures 90 times that of Earth (equivalent to what we find at 1000 meters below the surface of our oceans), causes a runaway greenhouse effect that raises the surface temperatures up to 450ºC, to such as extent that metals like lead are in a liquid state on Venus.

At a height of between 45 km and 70 km above the surface there are dense layers of sulfuric acid clouds which totally cover the planet. Our continued explorations and observations of Venus seemed to indicate that the “superotation” was a permanent phenomenon. A team led by scientists and the University of Basque Country used images recorded by both day and night on Venus with the VIRTIS spectral camera on board the Venus Express, to measure these clouds over several months and have discovered new aspects of the “superotation.”

First, between the equator and the median latitudes of the planet there dominates a superotation with constant winds blowing from East to West. The wind speeds within the clouds decrease with height, from 370 km/h to 180 km/h. At these median latitudes, the winds decrease to a standstill at the pole, where an immense vortex forms. Other aspects of the superotation are that wind movements from north to south, or meridional, are very weak, about 15 km/h.

Second, unlike what was previously believed, the superotation appears to be not so constant over time. “We have detected fluctuations in its speed that we do not yet understand,” said the team of scientists, led by Agustín Sánchez Lavega. Moreover, for the first time they observed “the solar thermal tide” effect at high latitudes on Venus. “The relative movement of the Sun on the clouds and the intense heat deposited on them makes the superotation more intense at sunset than at sunrise”, they stated in their paper, which was published in Geophysical Research Letters.

“Despite all the data brought together, we are still not able to explain why a planet than spins so slowly has hurricane global winds that are much more intense than terrestrial ones and are, moreover, concentrated at the top of its clouds,” said Lavega. “This study has enabled advances to be made in a precise explanation of the origin of superotation in Venusian winds as well as in the knowledge of the general circulation of planetary atmospheres.”

Source: University of Basque Country press release

Posted on by Nancy Atkinson

Explosions on the Moon

Meteor strike on Moon recorded by Robert Spellman on August 9, 2008

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Meteor showers are great fun. The streaks and flashes create a special type of astronomical fireworks. But there are some people out there who enjoy meteor showers in a different way. They don’t watch the meteors. Instead, they watch the moon. There are fireworks there, too, in the form of explosions — equivalent to about 100 pounds of TNT — when meteors hit the lunar surface.

On August 9th, during the Perseid meteor shower, a couple of amateur astronomers fixed their cameras on the Moon and watched meteoroids slam into the lunar surface. Silent explosions produced flashes of light visible a quarter of a million miles away on Earth. It was a good night for “lunar Perseids.”

Meteor strike on the moon imaged by George Varros.
Meteor strike on the moon imaged by George Varros.

“I love watching meteor showers this way,” says George Varros, who recorded the impact shown above from his home in Mt. Airy, Maryland. The flash, which lit up a nighttime patch of Mare Nubium (the Sea of Clouds), was a bit dimmer than 7th magnitude, which Varros said was “an easy target for my 8-inch telescope and low-light digital video camera.”

Hours later, another Perseid struck, on the western shore of Oceanus Procellarum (the Ocean of Storms). This time it was Robert Spellman of Azusa, California, who caught the flash. “It’s exciting to witness these explosions in real time,” he says. “I used a 10-inch telescope and an off-the-shelf Supercircuits video camera.” Spellman has a website about his observations.

NASA’s Meteoroid Environment Office watches the moon during meteor showers, too. Rob Suggs at the Marshall Space Flight Center and his team have recorded more than 100 lunar explosions since 2005. “We monitor lunar meteors in support of NASA’s return to the Moon,” Suggs says. “The Moon has no atmosphere to protect the surface, so meteoroids crash right into the ground. Our program aims to measure how often that happens and answer the question, what are the risks to astronauts?”

But NASA’s official lunar meteor observatories in Alabama and Georgia were both off-line on August 9, so the NASA team didn’t see how many Perseids were hitting the Moon that night.

“This shows how amateur astronomers can contribute to our research,” points out Suggs. “We can’t observe the Moon 24-7 from our corner of the USA. Clouds, sunlight, the phase of the Moon—all these factors limit our opportunities. A global network of amateur astronomers monitoring the Moon could, however, approach full coverage.”

Suggs hopes other amateurs will take up this hobby of watching the moon during meteor showers, not only to improve NASA’s lunar impact statistics, but also to support the agency’s LCROSS mission: In 2009, the Lunar CRater Observation and Sensing Satellite (LCROSS) will intentionally dive into the Moon, producing a flash akin to a natural lunar meteor. Unlike natural meteoroids, which hit the Moon in random locations, LCROSS will carefully target a polar crater containing suspected deposits of frozen water. If all goes as planned, the impact will launch debris high above the lunar surface where astronomers can search the ejecta for signs of H2O. The impact flash (if not hidden by crater walls) and the debris plume may be visible to backyard telescopes on Earth. Here’s more details on the LCROSS impact.

If you’re interested in watching for meteor impacts on the moon, NASA has a FAQ page, and telescope tips.

News Source: Science@NASA

Posted on by Nancy Atkinson

Pushing the Polite Boundaries of Science About Dark Matter

Hubble and Chandra composite image showing possible dark matter. Credit: X-ray(NASA/CXC/Stanford/S.Allen); Optical/Lensing(NASA/STScI/UC Santa Barbara/M.Bradac)

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Rumors are spinning faster than a neutron star about the possibility that a European satellite mission called PAMELA may have made a direct detection of dark matter, the mysterious particles thought to make up as much of 85% of all matter in the Universe. Word got out in August at a conference about dark matter in Stockholm, Sweden where the PAMELA (Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics) team presented their preliminary findings to a few selected physicists. What information has leaked out says the satellite has detected more positrons than can be explained by known physics and that this excess exactly matches what dark matter particles would produce if they were annihilating each other at the center of the galaxy. But the PAMELA team is not allowing any more information to be made public, until they re-analyze their data and allow other scientists to evaluate and verify the findings. This is good, if not wonderful, in all respects – making sure their findings are peer reviewed before publishing their work and going public. (Does anyone remember the cold fusion debacle?) But in what seems to cross the line of good science — as well pushing the boundaries of what is just plain polite, two other scientists have published an abstract based on what was revealed to them at the conference.

Ever since cosmologists “concocted” dark matter to explain the matter that was obviously missing from the universe’s equation, scientists have speculated, worked, created models and worked some more to determine exactly what dark matter is. Recent findings (see here and here)seem to be bringing us closer to finding this mysterious substance, providing clues to what this stuff might be. The PAMELA data seems to point towards positrons, or anti-electrons.

Marco Cirelli from the CEA near Paris in France and Alessandro Strumia from the Università di Pisa in Italy presented their own analysis of the PAMELA data in this abstract. They say the data agrees with their own model called Minimal Dark Matter in which the particle responsible is called the “Wino.” They do reference their own work but interestingly, many of their references are from talks given at the conference on August 18-22. At one point they note, “The preliminary data points for positron and antiproton fluxes plotted in our figures have been extracted from a photo of the slides taken during the talk, and can thereby slightly differ from the data that the PAMELA collaboration will officially publish.”

Is this just a desire to “publish” something first, or is this real science?

Sources: ArXiv, ArXiv blog, Nature

Posted on by Nancy Atkinson

Countdown to Asteroid Flyby

Artist impression of Rosetta and Asteroid 2867 Steins. Credit: ESA

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Time critical is approaching for the Rosetta spacecraft and it’s flyby of the asteroid 2867 Steins. Closest approach is expected on September 5, at 20:58 CEST, (Central European Summer Time), 2:58 pm EDT (US Eastern Daylight Time). To help the public follow the flyby, the Rosetta team now has a blog available, and a timeline has also been posted. At the time of closest approach, Rosetta is planned to be 800 km from the asteroid, passing by at a speed of 8.6 km/s relative to Steins. Both Rosetta and Steins will be illuminated by the Sun, providing an excellent opportunity for science observations.

Although most scientific observations will take place in the few hours around closest approach, several instruments will be switched on for a longer time around the event.

Between 40 and 20 minutes before closest approach, Rosetta will be flipped and the spacecraft will switch to a specially designed asteroid fly-by mode, an optimal configuration that supports the intensive observation and tracking activity of the on-board instruments. The first images and results will be available for presentation to the media during a press conference on Saturday, September 6 at 12:00 CEST.

Asteroid Steins orbit. Credit: ESA
Asteroid Steins orbit. Credit: ESA

The timeline is as follows (more details are available in the Rosetta Blog — all times CEST (Central European Summer Time):

1 September
02:20 Instruments switched on (except OSIRIS which was already on for the navigation campaign)

4 September
07:20-11:20 Slot for possible trajectory correction manoeuvre (36 hours before closest approach)
13:20-18:20 Last opportunity to acquire images for optical navigation campaign

5 September
07:20-10:20 Slot for possible trajectory correction manoeuvre (12 hours before closest approach)
10:20 Navigation cameras switch to tracking mode – initially both used, then use CAM ‘A’ only (to be decided)
11:00 Uplink fly-by commands for asteroid fly-by mode (AFM)
Includes an update to the command profile already on board & the final updated AFM commands (only if 1 CAM at least is tracking)
20:18-20:38 Spacecraft flip over
20:39 Spacecraft switches automatically to asteroid fly-by mode
20:56 Sun illuminates Rosetta from the back and the asteroid fully
20:58 Closest approach, at a planned distance of 800 km from the asteroid
22:27 First post-fly-by acquisition of signal (AOS) – telemetry received via NASA’s Goldstone ground station
22:30 Start of science data download via Goldstone

6 September
12:00 Live streaming of Rosetta Steins fly-by press conference from the European Space Operations Centre begins
13:00 Images from fly-by published on ESA web
15:00 End of press conference streaming
16:01 End of reception of first set of science data

News Source: ESA

Posted on by Nancy Atkinson

New Eye to the Universe Under Construction

The LSST, or the Large Synoptic Survey Telescope is a large survey telescope being constructed in northern Chile. When operational in 2015, it will be the widest, fastest, deepest eye of the new digital age, providing timelapse digital imaging across the entire night sky every three days, mapping the structure of our dynamic universe in three dimensions and exploring the nature of dark matter and dark energy. LSST hit a major milestone in its construction when the primary mirror blank was recently created. Project astronomers say the single-piece primary and tertiary mirror blank cast for the LSST is “perfect.”

The 51,900 pound (23,540 kg) mirror blank was fired in the oven at the University of Arizona’s Steward Observatory Mirror lab in Tucson, Arizona. It consists of an outer 27.5-foot diameter (8.4-meter) primary mirror and an inner 16.5-foot (5-meter) third mirror cast in one mold. It is the first time a combined primary and tertiary mirror has been produced on such a large scale.

LSST will have three large mirrors to give crisp images over a the largest field of view that will be available. The two largest of these mirrors are concentric and fit neatly onto a single mirror blank.
LSST was recently the recipient of two large gifts: $20 million from the Charles Simonyi Fund for Arts and Sciences, and $10 million from Bill Gates. The finished mirror is scheduled to be delivered in 2012.

More information about LSST.

News Source: LSST press release