Posted on by Nancy Atkinson

Improving the Conversation: NASA Begins Upgrade to Deep Space Network

This image of the Canberra complex shows four Deep Space Network antennas. The Deep Space Network is managed by NASA's Jet Propulsion Laboratory in Pasadena, Calif. Image credit: NASA/JPL/CDSCC

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All the robotic missions to various points in our solar system wouldn’t be possible if not for the Deep Space Network. It’s not just sending commands and receiving data, but also orbit determination, or keeping track of where the spacecraft are with radiometric tracking data so that spacecraft navigators can get probes exactly where the scientists want them to go. The three 70-meter antennas, located at the DSN complexes at Goldstone, California, Madrid, Spain, and Canberra, Australia are more than 40 years old and show wear and tear from constant use, while new and improved technology and antennas now available would improve operations. NASA announced this week they will begin to replace its aging fleet of dishes with a new generation of 34-meter (112-foot) antennas by 2025.

NASA broke ground this week by beginning to work on the facilities near Canberra, Australia. NASA expects to complete the building of up to three 34-meter antennas by 2018. The decision to begin construction came on the 50th anniversary of U.S. and Australian cooperation in space tracking operations.

“There is no better way to celebrate our 50 years of collaboration and partnership in exploring the heavens with the government of Australia than our renewed commitment and investment in new capabilities required for the next five decades,” said Badri Younes, deputy associate administrator for Space Communications and Navigation at NASA Headquarters in Washington.

The new antennas, known as “beam wave guide” antennas, can be used more flexibly, allowing the network to operate on several different frequency bands within the same antenna. Their electronic equipment is more accessible, making maintenance easier and less costly. The new antennas also can receive higher-frequency, wider-bandwidth signals known as the “Ka band.” This band, required for new NASA missions approved after 2009, allows the newer antennas to carry more data than the older ones.

Source: JPL

Posted on by Nancy Atkinson

Buy Your Own Space Underwear

Koichi Wakata models J-Ware socks. Credit: NASA. Inset: J-Space/JAXA, via collectSPACE

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Remember the “long duration underwear” tested out by Japanese astronaut Koichi Wakata on board the ISS last year? Now you can buy your very own. The specially designed undies and other clothing called “J-ware” are on sale now for 10,500 yen or about $115 USD. J-ware is treated with antibacterial and deodorizing materials, so they can be worn for long periods of and are resistant to odors. “(For) two months I was wearing these underwear and there was no smell and nobody complained,” said Wakata. “I think that new J-ware underwear is very good for myself and my colleagues.”

Hurry, sizes and quantities are limited.

Here’s the English translation of the J-ware website,
 and the original Japanese version.

In addition to odor control, the clothes are designed to absorb water, insulate the body and dry quickly. They also are flame-resistant and anti-static.

Typically, clothes can only be worn for a few days in space, and especially the clothing worn by astronauts as they exercise. Since there’s no laundromat in space, the clothing is discarded as garbage.

Astronaut Takao Doi, who flew with a shuttle crew in early 2009 to deliver Japan’s Kibo laboratory to the station, exercised as much as his crewmates, but his clothes stayed dry.

Wakata’s clothes include long- and short-sleeved shirts, pants, shorts and underwear. Special socks have a separate pouch for the big toes (see top image) so the astronauts can use their feet like an extra pair of hands, helpful for anchoring themselves on the floor while doing work on the station.

Source: collectSPACE

Posted on by Nancy Atkinson

New Results from Stardust Mission Paint Chaotic Picture of Early Solar System

Secondary electron image of the Coki section analyzed in this study showing mineral shards surrounded by compressed aerogel. Credit: Lawrence Livermore National Lab.

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One of the most surprising results from the Stardust mission – which returned comet dust samples to Earth in 2006 – is that comets don’t just consist of particles from the icy parts of the outer solar system, which was the common assumption, but also includes sooty dust from the hot, inner region close to the Sun. A new study confirms this finding, and also provides the first chronological information from the Wild 2 comet (pronounced like Vilt 2). The find paints a chaotic picture of the early solar system.

Even some of the first looks at the cometary particles returned by Stardust showed that contrary to the popular scientific notion, there was enough mixing in the early solar system to transport material from the sun’s sizzling neighborhood and deposit it in icy deep-space comets. Whether the mixing occurred as a gentle eddy in a stream or more like an artillery blast is still unknown.

“Many people imagined that comets formed in total isolation from the rest of the solar system. We have shown that’s not true,” said Donald Brownlee back in 2006, principal investigator for Stardust.

The new study, conducted by scientists from Lawrence Livermore (Calif.) National Laboratory, shows the dust from comet 81P/Wild 2 has been altered by heating and other processes, which could have only occurred if a transport of space dust took place after the solar system formed some 4.57 billion years ago.

“The mission was expected to provide a unique window into the early solar system,” the team, led by Jennifer Matzel wrote in their paper, “by returning a mix of solar system condensates, amorphous grains from the interstellar medium, and true stardust – crystalline grains originating in distant stars. Initial results, however, indicate that comet Wild 2 instead contains an abundance of high-temperature silicate and oxide minerals analogous to minerals in carbonaceous chondrites.”

Corresponding false color mineral map overlaid on a montage of brightfield Transmission Electron Microscope (TEM) images.

They analyzed a particle from the comet, about five micrometers across, known as Coki. The particle does not appear to contain any of the radiogenic isotope aluminum-26, which implies that this particle crystallized 1.7 million years after the formation of the oldest solar system solids. This means that material from the inner solar system must have traveled to the outer solar system, across a period of at least two million years.

“The inner solar system material in Wild 2 underscores the importance of radial transport of material over large distances in the early solar nebula,” said Matzel. “These findings also raise key questions regarding the timescale of the formation of comets and the relationship between Wild 2 and other primitive solar nebula objects.”

The presence of CAIs in comet Wild 2 indicates that the formation of the solar system included mixing over radial distances much greater than anyone expected.

Sources: LLNL, Astrobiology

Posted on by Tammy Plotner

Weekend SkyWatcher’s Forecast – February 26-28, 2010

Greetings, fellow SkyWatchers! It’s another snowy, moonlit weekend, but that doesn’t mean we can’t enjoy some astronomy together! It’s time to check out Saturn, walk along the ejecta on the Moon and just take a look at a very beautiful star. If you’re ready to learn some history, mystery and facts, then follow me into the backyard….

February 26, 2010 – Today we celebrate the birth on this date of many astronomers, starting in 1786 with Francois Arago, who discovered the solar chromosphere and made astonishingly accurate estimates of planetary diameters. Arago’s experiments proved the wave theory of light and contributed to the laws of polarization. Following in 1842 was astronomer and author Camille Flammarion, who studied multiple stars, the Moon, and Mars. Although erroneous in some observations (‘‘May we attribute to the color of the herbage and plants which no doubt clothe the plains of Mars, the characteristic hue of that planet.’’), Flammarion was entrusted with a personal copy of the Messier Catalog, including the author’s notes, which he later revised. Last is the 1864 birth of John Evershed, who contributed mightily to solar physics when he photographically discovered that gases in sunspots flowed horizontally from the center toward their edges, an effect now named for him!

Now, let’s check out Saturn…


For a small telescope at low power, a first glimpse of Saturn is far from the grand image often portrayed of the ringed planet. Instead of beautiful, Hubble-like images, the viewer is greeted with something that looks more like a sesame seed on a black saucer than a fascinating distant world. But don’t give up! No matter what telescope size you use, the image is more dependent on seeing conditions (such as the steadiness of the atmosphere and transparency) rather than aperture. Even at low power, watching Saturn’s moons orbit over a period of days is very rewarding. And even a very small telescope will reveal Saturn’s ring structure. As optic size increases, so do details on successive nights. Look for such wonders as the wide dark band known as the Cassini division and the dark shadow of the planet’s orb against the rings. Sharp-eyed observers often spy the ‘‘Encke gap’’—the thin, minor ring around the outside. Subtle shadings and the ring shadows on Saturn’s yellowish globe await! Try sketching while observing, even if you throw it away later. When sketching, the eye and the mind coordinate to pick up on finer details than seen by just observing alone. Be sure to take plenty of time! When the one pure moment of seeing and stability combine, even the smallest of telescopes will reward you with a view you’ll never forget.

Afterwards, relax and enjoy the Delta Leonid meteor shower activity. Burning through our atmosphere at speeds of up to 24 kilometers per second, these slow travelers will seem to radiate from a point around the middle of Leo’s ‘‘back.’’ The fall rate is rather low at around 5 per hour and the moonlight will greatly interfere with fainter meteors, but they are still worth keeping a watch for!

February 27, 2010 – Today let’s celebrate the 1897 birth on this date of Bernard Lyot, master of optics. He invented the polariscope, and produced the first solar coronagraph. He also made the first motion pictures of solar prominences. Lyot was an astute observer, and realized that the lunar surface had similar properties to volcanic dust. He didn’t see canals on Mars but observed sandstorms there, as well as atmospheric conditions on other planets. The Lyot filter is well known, and so is his micrometer, a device used to make precise distance measurements, especially those between close double stars. By all accounts a wonderful and generous man, Lyot sadly died of a heart attack while returning from seeing an eclipse.

With such bright sky, it’s going to be difficult to practice much astronomy—or is it? There are always some very cool things to do if you just know where to look! Let’s head for the eighth brightest star in the sky—Procyon.

Often called ‘‘the one who proceeds the Dog,’’ Procyon also represents a dog, the beloved pet of Helen of Troy. If you haven’t noticed, Alpha Canis Minoris See Procyon is also the eastern member of what is sometimes called the ‘‘Winter Triangle,’’ appearing above the horizon before the Dog Star, Alpha Canis Majoris. At 0 magnitude, it’s in fair competition with the other trio members: dazzling Sirius and mighty Betelgeuse. At a little more than 11 light-years away, it is also one of the closest stars to our Solar System. Now just stop and look at this beautiful star. Arabic tales describe Procyon and Sirius as two sisters, who along with their brother—Canopus—tried to cross the sky when they came to the Great Sky River. When they both entered the Milky Way and tried to swim across, only Sirius was strong enough to make it and now stands on the southern bank of that river of stars. Left alone to the north as her siblings moved on, Procyon is often referred to in mythology as ‘‘she who weeps.’’ Not surprisingly, astrology also associates Procyon with watery catastrophes!

February 28, 2010 – Tonight it’s a Full Moon… Since the heaviest snow usually falls during this month, native Indian tribes of the north and east most often called February’s full Moon the Full Snow Moon. Some tribes also referred to this Moon as the Full Hunger Moon, since harsh weather conditions in their areas made hunting very difficult. Given the huge amount of snowfall that has occurred during this month, I think Snow Moon quite fits! Tonight, aim your optics toward the Moon and study an impact crater large enough to have blasted lunar material back to Earth. Its name is Tycho…

Take one glance at the lunar Southern Hemisphere, and you can’t miss the dazzling display of 85-kilometer-wide Tycho, and its brilliant splash ray pattern. Perhaps 100 million years ago a comet, an asteroid, or a large meteorite impacted the Moon, flinging debris far and wide. One of Tycho’s ejecta paths (rays) crosses the Apollo 17 landing site almost 2,000 kilometers away, where it caused a landslide, revealing deeper materials. Shining like a beacon in Tycho’s center is a mountain peak originating from below the surface crust. The crater floor is lumpy and the rim broken by the force of the impact.

Could a collision like Tycho’s create Earth-bound meteoroids? Indeed, you may have walked on one unaware! The first confirmed lunar meteorite was found in 1979 in Antarctica, but it was many years before its true identity was known. Confirmation required comparison of its chemical composition to that of Apollo lunar samples. To date, only around 40 confirmed lunar meteorites are known, but as many as one in every thousand may have originated from our nearest neighbor. Noble gas measurements show some of these materials may have left the lunar surface up to 20 million years ago, but most are around 100,000 years old. They might resemble terrestrial rocks, but ones with their chemical composition are found only on the Moon. Have a look at Tycho and imagine the power that sculpted this mighty crater!

Credits for this week’s awesome images belong to: Tycho Crater – Roger Warner, Saturn – Wes Higgins, Procyon- Palomar Observatory, courtesy of Caltech and historical images.

Posted on by Nancy Atkinson

More Jaw-Droppers from Cassini

The small moon Janus is almost hidden between the planet's rings and the larger moon Rhea.Credit: NASA/JPL/Space Science Institute

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The Cassini mission keeps churning out the hits, and here’s a collection of some of the latest stunning images released by the CICLOPS (Cassini Imaging for Central Operations) team. Above, the small moon Janus is almost hidden between the planet’s rings and the larger moon Rhea. The northern part of Janus can be seen peeking above the rings in this image of a “mutual event” where Janus (179 kilometers, 111 miles across) moved past Rhea (1,528 kilometers, 949 miles across). Mutual event observations such as this one, in which one moon passes close to or in front of another, help scientists refine their understanding of the orbits of Saturn’s moons. Click here to see a movie of the event.

Saturn's potato-shaped moon Prometheus is rendered in three dimensions in this close-up from Cassini. Credit: NASA/JPL/Space Science Institute

Grab your 3-D glasses for this one! This 3-D view is a close-up of Saturn’s potato-shaped moon Prometheus, showing the moon’s leading hemisphere. The image was created by combining two different black and white images that were taken from slightly different viewing angles. The images are combined so that the viewer’s left and right eye, respectively and separately, see a left and right image of the black and white stereo pair when viewed through red-blue glasses.

Saturn and Enceladus. Credit: NASA/JPL/Space Science Institute

At first glance, you might think this scene simply shows a bright chunk of Saturn, along with a crescent of the moon Enceladus at top right. But a closer look at the center of the image reveals a dramatic surprise: plumes of water ice spew out from the famed fractures known as “tiger stripes” near the south pole of the moon. And one other surprise: Although it may appear that Enceladus (504 kilometers, 313 miles across) is in the background here, the moon actually is closer to the spacecraft than Saturn is. This view looks most directly toward the side of Enceladus that faces away from Saturn. North on Enceladus is up and rotated 1 degree to the left.

For more great images, check out the CICLOPS website, or NASA’s Cassini website.

Posted on by Nancy Atkinson

End of an Era: “Lasts” for Shuttle Program

Final test firing of reusable solid rocket motor FSM-17 on Feb. 25 in Promontory, Utah. Image Credit: NASA

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Yesterday, NASA’s Space Shuttle Program conducted the final test firing of a reusable solid rocket motor, in Utah. Look to see the words “final” and “last” frequently over the next few months in regards to the space shuttle. “There is a whole series of lasts coming up,” said space shuttle launch director Mike Leinbach at Endeavour’s landing earlier this week, who talked about the “majesty of this ship” and “people who have fallen in love with this machine.” It’s going to be hard to let them go,” he said, “but we’ve been given a new direction and we’ll process that last shuttle and fly that last mission and move on.”

Here’s a few notes and recent news items on the end of the shuttle program:

Smoke curls into the Utah skies as FSM-17 completes its successful test firing. Image Credit: NASA

Some spectacular pictures from the final SRB test. FSM-17, (that’s flight support motor, not Flying Spaghetti Monster) burned for approximately 123 seconds — the same time each reusable solid rocket motor burns during an actual space shuttle launch.

The final test was conducted to ensure the safe flight of the four remaining space shuttle missions. A total of 43 design objectives were measured through 258 instrument channels during the two-minute static firing.
The first test was in July 1977. The motors, built by ATK motors have successfully launched the space shuttle into orbit 129 times – out of 130 attempts.

You can watch the entire test firing video below.

And speaking of the end of the shuttle program, NASA held an in-house competition to design a shuttle commemorative patch, and last week, the winners were announced. They are beautiful designs, so I’ll post the 3 winners.

Blake Dumesnil's winning design will become NASA's official space shuttle commemorative emblem. (NASA)

Blake Dumesnil, a Hamilton Sundstrand camera engineer from Johnson Space Center, designed the patch, above, which was chosen by judges out of the 85 designs submitted by the agency’s past and present workforce.

It shows a launching space shuttle bordered by a US flag and stars to commemorate both NASA’s orbiter fleet and the astronauts whose lives were lost while flying aboard them.

Second place went to Jennifer Franzo from the Michoud Assembly Facility, New Orleans. Her “Mission Complete” logo shows a shuttle in orbit “tipping its wing to the world, as a way to say ‘thank you’ and ‘farewell’ just as a cowboy would wave goodbye into the sunset.”

Tim Gagnon's third place design will fly with the other 84 contest entries on a CD aboard shuttle Atlantis. (NASA)

Third place went to Tim Gagnon, a former subcontractor employee at Kennedy Space Center, Florida, whose patch designs have been worn by the astronaut crews on shuttle and International Space Station flights. His contest entry focused on the “orbiter coming home for a safe landing at the conclusion of its final mission.”

Leonardo in the SSPF. Image: Nancy Atkinson

One other news item for one of the final shuttle flights. On STS-133, the second-to-last scheduled shuttle flight, the Leonardo Multi Purpose Logistics Module (MPLM) will be brought up to the ISS to become a Permanent Multipurpose Module (PMM).

Leonardo is currently undergoing processing to bring supplies to the ISS on the STS-131 mission, and I visited the Space Station Processing Facility last week to view the module up close. After returning home from this mission, Leoardo will undergo modifications to ensure safe, long-term operation as the PMM, and to increase the amount of mass it can carry to orbit.

Inside the PMM, experiments in fluid physics, materials science, biology, biotechnology and other microgravity experiments may be conducted.

MPLM’s have been flown inside the payload bays of the shuttles, successfully delivering vital hardware and supplies to the station. The new use for this proven carrier will provide more room and enhance the use of the station.

As promised, here’s the video of the SRB test:

Sources: NASA, collectSPACE, NASA

Posted on by Jean Tate

Gravity Formula

The gravity formula that most people remember, or think of, is the equation which captures Newton’s law of universal gravitation, which says that the gravitational force between two objects is proportional to the mass of each, and inversely proportional to the distance between them. It is usually written like this (G is the gravitational constant):

F = Gm1m2/r2

Another, common, gravity formula is the one you learned in school: the acceleration due to the gravity of the Earth, on a test mass. This is, by convention, written as g, and is easily derived from the gravity formula above (M is the mass of the Earth, and r its radius):

g = GM/r2

In 1915, Einstein published his general theory of relativity, which not only solved a many-decades-long mystery concerning the observed motion of the planet Mercury (the mystery of why Uranus’ orbit did not match that predicted from applying Newton’s law was solved by the discovery of Neptune, but no hypothetical planet could explain why Mercury’s orbit didn’t), but also made a prediction that was tested just a few years’ later (deflection of light near the Sun). Einstein’s theory contains many gravity formulae, most of which are difficult to write down using only simple HTML scripts (so I’m not going to try).

The Earth is not a perfect sphere – the distance from surface to center is smaller at the poles than the equator, for example – and it is rotating (which means that the force on an object includes the centripetal acceleration due to this rotation). For people who need accurate formulae for gravity, both on the Earth’s surface and above it, there is a set of international gravity formulae which define what is called theoretical gravity, or normal gravity, g0. This corrects for the variation in g due to latitude (and so both the force due to the Earth’s rotation, and its non-spherical shape).

Here are some links that you can follow to learn more about gravity formulae (or gravity formulas): Newton’s theory of “Universal Gravitation” (NASA), International Gravity Formula(e) (University of Oklahoma), and Newton’s Law of Gravity (University of Oregon).

Many aspects of gravity, including a gravity formula or three, are covered in various Universe Today articles. For example, New Research Confirms Einstein, Milky Way Dwarf Galaxies Thwart Newtonian Gravity?, and Modifying Gravity to Account for Dark Matter. Here’s some information on 0 gravity.

Astronomy Cast’s episode Gravity gives you much more on not just one gravity formula, but several; and Gravitational Waves is good too. Be sure to check them out!

Sources:
University of Nebraska-Lincoln
NASA
UT-Knoxville

Posted on by Jean Tate

Ephemerides

Cuneiform clay tablet. Image Credit: Bristol University

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Ephemerides is the plural form of ephemeris; one ephemeris, two (three, four, …) ephemerides. Why such a strange word? Why not ‘ephemerises’? Because of its Greek-via-Latin origin, and because it’s a word rarely used outside an academic/technical setting (there are only a few other words in English which form plurals in this way, one is iris -> irides). An ephemeris is a table (or similar) giving the position in the sky of astronomical objects, at a particular time (or set of times).

The most common ephemerides are those of solar system bodies, such as the planets, asteroids, and comets; ephemerides of greatest public interest are those of solar eclipses. For amateur astronomers, ephemerides giving eclipses, occulations, and transits – of asteroids, the Galilean moons, eclipsing binaries, exoplanets, etc – are of particular interest.

Waaay back when, ephemerides took a very long time to calculate, because all calculation was done by hand; today there are free apps and software packages you can download that will generate ephemerides for you, even ones of entirely fictional things such as settings for a sci-fi novel.

And here’s a fun fact: you can generate half-way decent ephemerides of the classical planets (Mercury, Venus, Mars, Jupiter, Saturn), the Moon, and of solar eclipses, using a heliocentric, Ptolemaic model! Today, for high accuracy – especially over centuries and millennia – ephemerides of Mercury, the Moon, etc require gravity to be modeled using General Relativity (GR), rather than Newtonian mechanics. And accurate ephemerides for Pioneer 10 and 11? Well, even GR is not enough … you have to model the Pioneer anomaly!

There two NASA websites nicely bracket ephemerides: Ephemeris (the briefest of introductions), and the HORIZONS web interface (for precision ephemerides). Ephemerides and Orbital Elements is the IAU Minor Planet Center’s site for the most up-to-date ephemerides, and Description of JPL Solar System Ephemeris (NRAO) explains some of the subtleties involved in generating, and interpreting, ephemerides.

Some of the many Universe Today articles which reference ephemerides: Observing Near-Earth Asteroid TU24, Gravity Anomaly Challenges MESSENGER Mission, and Newly Discovered Asteroid 2009 FH to Buzz the Earth Tonight.

Constellations, an Astronomy Cast episode very relevant to ephemerides; check it out!

Posted on by Jean Tate

What is Space?

First, some simple answers: space is everything in the universe beyond the top of the Earth’s atmosphere – the Moon, where the GPS satellites orbit, Mars, other stars, the Milky Way, black holes, and distant quasars. Space also means what’s between planets, moons, stars, etc – it’s the near-vacuum otherwise known as the interplanetary medium, the interstellar medium, the inter-galactic medium, the intra-cluster medium, etc; in other words, it’s very low density gas or plasma (‘space physics’ is, in fact, just a branch of plasma physics!).

But you really want to know what space is, don’t you? You’re asking about the thing that’s like time, or mass.

And one simple, but profound, answer to the question “What is space?” is “that which you measure with a ruler”. And why is this a profound answer? Because thinking about it lead Einstein to develop first the theory of special relativity, and then the theory of general relativity. And those theories overthrew an idea that was built into physics since before the time of Newton (and built into philosophy too); namely, the idea of absolute space (and time). It turns out that space isn’t something absolute, something you could, in principle, measure with lots of rulers (and lots of time), and which everyone else who did the same thing would agree with you on.

Space, in the best theory of physics on this topic we have today – Einstein’s theory of general relativity (GR) – is a component of space-time, which can be described very well using the math in GR, but which is difficult to envision with our naïve intuitions. In other words, “What is space?” is a question I can’t really answer, in the short space I have in this Guide to Space article.

More reading: What is space? (ESA), What is space? (National Research Council of Canada), Ned Wright’s Cosmology Tutorial, and Sean Carroll’s Cosmology Primer pretty much cover this vast topic, from kids’ to physics undergrad’ level.

It’s hard to know just what Universe Today articles to recommend, because there are so many! Space Elevator? Build it on the Moon First illustrates one meaning of the word ‘space’; for meanings closer to what I’ve covered here, try New Way to Measure Curvature of Space Could Unite Gravity Theory, and Einstein’s General Relativity Tested Again, Much More Stringently.

Astronomy Cast episodes Einstein’s Theory of Special Relativity, Einstein’s Theory of General Relativity, Large Scale Structure of the Universe, and Coordinate Systems, are all good, covering as they do different ways to answer the question “What is space?”

Source: ESA

Posted on by Jean Tate

This Week’s astro-ph Preprints: Jean Tate’s Best Pick

Examples of ring objects (Mizuno et al./Spitzer)

It goes by the super-catchy (not!) title “A Catalog of MIPSGAL Disk and Ring Sources”. I chose it, over 213 competitors, because it’s pure astronomy, and because it’s something you don’t need a PhD to be able to do, or even a BSc.

Oh, and also because Don Mizuno and co-authors may have found two, quite local, spiral galaxies that no one has ever seen before!

Some quick background: arXiv has been going for several years now, and provides preprints, on the web, of papers “in the fields of physics, mathematics, non-linear science, computer science, quantitative biology and statistics”. It’s owned, operated and funded by Cornell University. astro-ph is the collection of preprints classified as astro physics; the “recent” category in astro-ph is the new preprints submitted in the last week.

When I have any, one of my favorite spare-time activities is browsing astro-ph (Hey, I did say, in my profile, that I am hooked on astronomy!)

Briefly, what Mizuno and his co-authors did was get hold of some of the images from Spitzer (something that anyone can do, provided their internet connection has enough bandwidth), and eyeball them, looking for things which look like disks and rings. Having found over 400 of them, they did what the human brain does superbly well: they grouped them by similarity of appearance, and gave the groups names. They then checked out other images – from different parts of Spitzer’s archive, and from IRAS – and checked to see how many had already been cataloged.

And what did they find? Well, first, that most of the objects they found had not been cataloged before, and certainly not given definite classifications! Many, perhaps most, of the new objects are planetary nebulae, and their findings may help address a long-standing puzzle in this part of astronomy.

MGE314.2378+00.9793 (Mizuno et al./Spitzer)
MGE351.2381-00.0145 (Mizuno et al./Spitzer)

But they also may have found two local spiral galaxies, which had not been noticed before because they are obscured by the gas-and-dust clouds in the Milky Way plane. How cool is that!

Here’s the ‘credits’ section of the preprint: “This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA in part through an award issued by JPL/Caltech. This research made use of the SIMBAD database and the Vizier catalog access tool, operated by the Centre de Donnees Astronomique de Strasbourg. This research has also made use of NASA’s Astrophysics Data System Bibliographic Services.”

And here’s the preprint itself: arXiv:1002.4221 A Catalog of MIPSGAL Disk and Ring Sources; D.R. Mizuno(1), K. E. Kraemer(2), N. Flagey(3), N. Billot(4), S. Shenoy(5), R. Paladini(3), E. Ryan(6), A. Noriega-Crespo(3), S. J. Carey(3). ((1) Institute for Scientific Research, (2) Air Force Research Laboratory, (3) Spitzer Science Center, (4) NASA Herschel Science Center, (5) Ames Research Center, (6) University of Minnesota)

PS, going over the Astronomy Cast episode How to be Taken Seriously by Scientists is what motivated me to pick this preprint (however, I must tell you, in all honesty, that there are at least ten other preprints that are equally pickable).