The Cosmic Mirror
By Daniel Fischer
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A German companion - only available here!
Current mission news: MGS (latest pictures!) + Cassini + Stardust

Updates from the Mars rovers and Mars Express
Opportunity has seen the first annular solar eclipses by Phobos while Spirit has reached the crater Bonneville. MER Press Release of March 11, Pancam raw images of Phobos events on Sol 47 and Sol 45, the very first b/w and color Bonneville panoramas, the Status, a JPL Spotlight on driving on Mars and coverage of March 16: AP. March 12: New Sci., FT, LAT, ST, CENAP. March 11: BBC, AP, SC (other and another story). March 10: BBC, SC. March 9: Dsc. Mars Express: coverage of March 16: AP. March 11: CENAP.
Update # 274 of Tuesday, March 16, 2004
Spotting an Oort cloud member? / 2nd data release of SDSS / Rosetta to visit 2 asteroids

Perihelion 76 AU, aphelion 990 AU, period 12300 years: the first body residing in the Oort cloud?

2003 VB12 stays way outside the Kuiper Belt at all times / Red color, high albedo, diameter 1300 to 1800 km / Could be the first of many such objects at the inner edge of the Oort cloud

At 21st magnitude it would be a pretty bright object for a resident of the Kuiper Belt - but the remarkable celestial object 2003 VB12 orbits the Sun way beyond this zone of icy bodies that has a rather sharp outer edge at 49 AU (7 billion km; see also Update # 208 story 5): The newest solar system discovery never comes closer to the Sun than 76 AU or 11.3 billion km and travels as far away as 990 AU or 148 billlion km! Never before has a body been observed that always stays so far from the Sun: Even the extreme 2000 CR105, which belongs to the so-called extended scattered disk component of the Kuiper Belt (see Update # 222 small items) and has an aphelion distance of 410 AU, spends at least its perihelion inside the Belt (although with a minimum solar distance of 44 AU it never approaches Neptune and its origin remains a mystery). 2003 VB12 however, living twice as far from the Sun, could well be the first member of the Oort cloud detected directly - and it is quite an object!

Not only is the orbit of the body - measuring 1300 to 1800 km - unique (and of a kind that had not even been predicted before): The composition of 2003 VB12 is remarkable as well. On the one hand its surface is extremely red (in the whole solar system only Mars is redder): This by itself is not unusual in the outer solar system, but here it occurs in combination with an enormous albedo! Precise values for diameter and albedo are still lacking: The Spitzer Space Telescope has tried - and failed - to spot the body by its heat radiation (as has the 30-meter IRAM radio telescope), so it must be smaller than about 1700 km. On the other hand no obvious outer solar system compounds are known that are red and have an albedo larger than 25%, and at that extreme value 2003 VB12 would measure some 1300 km, based on its visual brightness. Together with Ixion, Quaoar and 2004 DW (see Update # 272 small items; a precise diameter is still not known) 2003 VB12 thus belongs to the select group of »half« or »3/4« Plutos.

With that the question »What is a planet?« surfaces once again. 2003 VB12 - which its discoverer, Caltech's Michael Brown, wants to name Sedna, after an Inuit ocean goddess - was discovered in November 2003 with the 1.2-meter Schmidt of the Palomar Observatory: Thanks to a new CCD camera mit 170 megapixels it has already scanned 15% of the sky for slowly moving point sources. Later overlooked images of Sedna were found in archival data dating back to 2001, so a 3-year arc is now available: Another 6 months from now the orbit should be known well enough that the object is given a permanent number, and the name should become official soon thereafter. But a planet, »the tenth« even, Sedna will not be for Brown: »In my opinion this is not a planet,« he declared at a NASA teleconference to dozens of space reporters (including yours truly) on March 15 - and Pluto for him isn't one either.

A widely accepted definition of planet does not exist (anymore), with all the weird bodies found in our solar system and elsewhere in the last decade or so, but Brown's criterion sounds obvious: Thou shalt only be called a planet when there exist no other objects of similar size in similar orbits! Thus Pluto ceases to be one for good (and if discovered only today, it would never have become one in the first place) - and it doesn't help Sedna to the status of a »real« planet that at present no other bodies are known on similar orbits. For Brown is confident that during the ongoing survey with the 1.2-meter Oshin Schmidt (as well as during an upcoming one with the 5-meter Hale telescope) many relatives of Sedna will be discovered, some of them even larger in size. And while near their perihelia they should well be within reach of moderate amateur telescopes, that is provided they share Sedna's high albedo.

Even the very first detection of such an object suffices for Brown to draw far-reaching conclusions. Current thinking is that the Oort Cloud was formed in the youth of the solar system when planetesimals were kicked out of the zone between Saturn and Neptune by close encounters with the large planets. Sedna probably suffered the same fate - but was stopped on its way out by a close encounter with a star, then settling into its present orbit. And if those processes happened often (as the discovery of more Sedna-class bodies would demonstrate), that would be evidence for the young Sun residing in a dense star cluster where such encounters were frequent. A whole population of Sednas - which the surveys would uncover within the next five to ten years - would also make the inner reaches of the Oort cloud much more massive than once thought. In any case the known solar system has just gotten a bit bigger.

An MPEC with precise orbital elements, a Caltech Special Page, a table of all known Scattered Disk objects (plus Centaurs - and VB12), JPL [Science@NASA], Spitzer, NASA, Caltech [SR] and MPIfR Press Releases.
Coverage by S&T, Ast., ACC, Dsc., NSU, Plan. Soc., APOD, HC (earlier), Scotsman, USA Today, BBC (earlier), LAT, AFP (earlier), FT, Guardian, VoA, New Sci., SC, ST, AFP(D), NZ, RP. Earlier rumors: Australian, PA, ST, CENAP, NZ.

Cassini catches clumps in the F ring

of Saturn - two images taken nearly two hours apart show these clumps as they revolve about the planet: PhotoJournal.
Magnetic fields of Uranus, Neptune explained - according to a new study their interior structure is different from those of Jupiter and Saturn, with only a thin layer of metallic convecting fluid: Harvard Gazette, AFP, BdW.
Fossil meteorites in Sweden: PSRD. How to defend against NEAs: SC. UK gov't ignores threat: BBC.

November solar flare was an 'X45'

Physicists in New Zealand have shown that last November's record-breaking solar explosion (see Update # 264 lead sidebar 1) was much larger than previously estimated, thanks to innovative research using the upper atmosphere as a gigantic x-ray detector - this revises the flare's size from a merely huge X28 to a "whopping" X45: AGU Press Release.
A detailled list of all the consequences - on technical systems and otherwise - of the high solar activity last October/November has now been prepared by the WWW Greifswald.
A rare SOHO shot of an eruptive prominence over 700'000 kilometres across: ESA.

Sloan Digital Sky Survey releases 6 Terabytes of data to public

One of the largest astronomy catalogs ever compiled was released to the public on March 15 by the Sloan Digital Sky Survey (SDSS). With photometric and spectroscopic observations of the sky gathered during the last two years, this second data release (DR2) offers six terabytes of images and catalogs, including two terabytes in an easy to use searchable database. While members of the SDSS international collaboration have written more than 200 scientific papers with SDSS data, they know that they have barely started: There is far more interesting science to be done and discoveries to be made with these data than they have time or people to do. This is why this data release is considered so important. Public searchable data in the survey have doubled from June 2003 to today.

The first public data release from the SDSS in 2003 contained information on 50 million objects, including spectra and redshifts for almost 200,000 of these objects. The SDSS is an ongoing survey that recorded its first observations in May 1998 and is funded for operations through Summer 2005. The 2.5-meter SDSS telescope is located at Apache Point Observatory in New Mexico and is operated by the Astrophysical Research Consortium. The telescope has two main instruments: an imaging camera, one of the largest ever built, and a spectrograph capable of recording data from 640 objects at a time. The camera creates images from digital scans through five filters: ultraviolet, green, red, and two infrared bands.

Scientific findings and ground-breaking discoveries already achieved with the DR2 data from the most distant quasars, to the coolest stars, the properties of galaxies to the sizes of asteroids, the structure of the halo of our Milky Way and the large-scale structure of the universe. DR2 consists of images from 3,324 square degrees of the Northern sky and more than 88 million galaxies, stars, and quasars. The survey is complete for objects as faint as 22.2 magnitude, three million times fainter than the faintest star that can be seen with the naked eye on a dark night. In addition to images from the SDSS telescope, the DR2 includes the spectra, and therefore redshifts, of 260,000 galaxies, 36,000 quasars, and 48,000 stars. The galaxy and quasar catalogs are the largest ever produced.

A paper by Abazajian & al., an SDSS Press Release, the 2nd Data Release, a collection of Pretty Pictures and the access interface Sky Server, meant for the general public, too.

Let's "blink" the Hubble UDF

A new website permits fast switching between the ACS and NICMOS view of the Hubble Ultra Deep Field. A first paper on what the UDF means was published only one day after is release by Bunker & al. And S&T, Ast., FT and Wired (earlier) on how the UDF was released to the world (and astronomers in particular), plus an FT OpEd.
GLARE finds a surprisingly large number (three) very high redshift galaxies (z=5.83, 5.79 and 5.94) in a same region of the southern GOODS field: Gemini Release.

Two asteroid flybys selected for Rosetta

On March 11 the Rosetta Science Working Team has made the final selection of the asteroids that Rosetta will observe at close quarters during its journey to Comet 67P/Churyumov-Gerasimenko: (2867) Steins and big (21) Lutetia lie in the asteroid belt between the orbits of Mars and Jupiter. Only after Rosetta's launch and its insertion into interplanetary orbit could the ESA mission managers assess how much fuel was actually available for fly-bys. Information from the European Space Operations Centre (ESOC) in Germany enabled Rosetta's SWT to select a pair of asteroids of high scientific interest, well within the fuel budget. The selection of these two targets was made possible by the high accuracy with which the Ariane 5 delivered the spacecraft into its orbit. This of course leaves sufficient fuel for the core part of the mission, orbiting Comet 67P/Churyumov-Gerasimenko for 17 months when Rosetta reaches its target in 2014. Meanwhile the commissioning of the spacecraft continues, and three instruments have already been switched on and tested.
March 15 Status, an ESA Press Release on the asteroids and coverage by BBC, ST, NZ, RP. Plus stellar occultations by Steins - the next one is on April 4! And a (German) launch blog from WDR.

MESSENGER at the Cape

NASA's MESSENGER spacecraft arrived in Cape Canaveral on March 10, for its scheduled May 11 launch toward Mercury: APL and KSC Press Releases. A paper on ESA's Venus Express: PDF.

ISS etc. Update

House Press Release, statements by Fisk and Weiler during a hearing and by O'Keefe before the Senate Appropriations Subcommittee, the NASA FY04 Operating Plan and coverage of March 15: SpaceRev, SC (other story). March 14: FT. March 13: Science News, HC, ST. March 12: DW (this is not quite the joke it sounds like; refer to these SC and RP stories for the legal complexities ...).
March 11: FT (earlier), AP, AFP, ST (earlier, still earlier).
The HST crisis - NASA will have the National Academy of Sciences review the matter after Gehman sees no showstopper for another Servicing Mission! Press releases by the House Science Comm. and Mikulski [SN], a NASA White Paper [SN] on the SM cancellation, an O'Keefe OpEd and coverage of March 14: CBS, SR, SC. March 12: HC, S&T, FT, BBC, AFP [Dsc.], SC, ST. March 11: IEEES, Nat'l review, SC. March 10: Daily Camera, UPI, SC.

Koptev to retire from reorganized Russian space agency

Yuri Koptev, the longtime head of the Russian space agency, will retire and be replaced by the head of the Russian Space Forces - just days after a major reorganization of the Russian government that included renaming Rosaviakosmos to "Federal Space Agency" and removing aircraft from its mandate: ST (earlier).

Pentagon harbors wild space plans such as robots building communications arrays hundreds of miles above the Earth, electromagnetic pulses cleansing space of nuclear explosions' lethal effects and raw materials turning themselves into orbiting sensors: Wired.

Taxi tests with Phoenix completed, a German proto-prototype for a possible RLV: EADS Press Release, Welt.

"Most sensitive sub-millimeter telescope" to be built in Chile

by Cornell and Caltech - it will have a 25-meter mirror and a bolometric array with 10'000 pixels but won't operate until 2012: Cornell Press Release.

How to turn a continent into a telescope - the ANITA neutrino telescope project for Antarctica: CSM.

  • Five planets in the evening sky in late March: Griffith Obs., CSM, SC.
  • Higgs particle sighted? A scientist says one of the most sought after particles in physics - the Higgs boson - may have been found, but the evidence is still relatively weak: BBC.
  • The pentaquark - has it been detected clearly or not? Kwork.
  • SETI project Phoenix has ended on March 5 - and no ET called in: SC.
  • Can you see the Great Wall from space? Yang thinks not: AFP. But one Apollo astronaut thinks otherwise: AP.


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Compiled and written by Daniel Fischer