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

Amateur rocket explodes instead of reaching space
Another attempt by space enthusiasts to reach space with a homebuilt rocket has failed on Sept. 19 when the Primera of the Civilian Space eXploration Team (CSXT) exploded shortly after liftoff: CNN, Space.com, Homepage, previews by CNN, SC.
Update # 243 of Saturday, October 5, 2002
Sky Disk mysteries unravel / Meteorite shocker / Exoplanet preferences / VLTI gets all 4 UTs to interfere / CMBR polarization detected
Extra: Belorussian translation of this page!

Germany's »Sky Disk« seen as key for archaeoastronomy

Much more has been learned about the mysterious bronze (age) disk unearthed in Germany (see Update # 236), now that the actual context of the discovery has been revealed: The perpetrators of the illegal dig have surrendered themselves to the police in July, the exact site has been located and professional excavations have begun on August 20. And while only a small fraction of the extended site on a hill near the town Nebra in Saxony-Anhalt has been investigated so far, it is already being hailed as a »German Stonehenge« in some circles.

While much cannot be seen there by the untrained eye, the local archaeologists now describe a circular wall of about 200 meters diameter, surrounded by a complex system of trenches - a site which, according to some artefacts found so far, has been in use for a thousand years (i.e. from about 1600 to 700 BC). The only direct astronomical clue is the geographical location: From the hill (»Mittelberg«) the Sun sets at the summer solstice directly behind the important Brocken mountain 80 km away. And many names of landmarks in the area carry astronomical-sounding names.

On the Mittelberg site the Sky Disk (the new offical name being »early bronze age bronze disk with a representation of the sky from Nebra«) had been buried for unknown reasons but with care. Thanks in part to the ongoing criminal investigation we even know its original orientation in the ground, which yields some clues for the interpretation of the celestial phenomena and geometrical figures put onto the disk (the authenticity of which is no longer in any doubt, thanks to several physical lab investigations):

  • There are two arcs, opposite to each other, of 82.7° each - exactly the distance between the northern- and southernmost points of sunset and sunrise from Saxony-Anhalt in the bronze age. Thus we have a mathematical clue as well that the disk belongs to the Nebra area.
  • The short arc in between the two big ones was on the bottom of the disk in the orientation it was found: This supports the interpretation as a »sun barge« travelling between sunset and sunrise. Another interpretation had been that we are dealing with a particularly bright section of the Milky Way.
  • The meaning of the two largest objects is uncertain: the Sun and the Moon or rather the Full Moon and a lunar crescent - or even phases of a lunar eclipse? Astronomers favor the latter view: It probably would have been too big an act of abstract thinking for our bronze age artist to visualize the Sun in a sky full of stars.
  • Seven of those stars form a tight pattern, the only one on the whole disk. While this could equally well mean the Plejades and the Praesepe star cluster or the small constellation Delphinus, preference is given to the Plejades: In contrast to the other interpretations this asterism plays a significant role in ancient texts.
  • The other stars are distributed on the disk in as random a fashion as possible when one actively tries to avoid the formation of any pattern - this has actually been demonstrated by experiments at Bochum University. A true random distribution with Poisson statistics would look much more clumpy.
What else do we know about the Star Disk? Its age is known to be 3600 years only because of other artefacts found in close proximity, esp. two swords - the design of which points to the Balkans or even ancient Greece. And we have evidence that the disk was reworked several times: Some original stars were removed when the horizon arcs were added some time later, and the rim of the disk was punched later still in an almost brutal fashion.
The use of the disk remains a mystery though. Were the horizon arcs applied for actual measurements? Was it a teaching tool for novices at the observatory? Was it purely a religious item? All which has been learned from the ongoing studies of the disk and the excavation will go into a book to be distributed widely next spring. And in 2004 an international conference will be held in nearby Halle to give the archaeologists and astronomers of the world an opportunity to voice their opinions. (Based on an interview with Prof. W. Schlosser of Bochum Univ. on Oct. 4 and other sources)
The 'official' (and very poorly designed!) Homepage of the disk and the excavation, with the new developments described here and esp. in this Press Release (all in German) and coverage by DPA, AP and MZ.

Meteorite shocker: Two different types on the same orbit

When on April 6 a bright bolide was seen over Southern Germany, the precise orbit determined from all-sky photographs was almost identical to the path in which the Pribram meteorite had come in exactly 40 years earlier (see Update # 236 story 3). Later a meteorite from the 2002 bolide was located near the famous Neuschwanstein castle (see Update # 241 small items), and everyone expected it to be of the same type as the Pribram, i.e. an ordinary chondrite of the type H5. Instead the Neuschwanstein turned out to be a rare enstatite chondrite of the class E6 - what was it doing on the same orbit? (Message by D. Heinlein on Sep. 20)
Another (old) review of Neuschwanstein.

Asteroid Hermes recovered?

The orbital elements of 2002 SY50 are similar to the big rock that approached Earth in 1937, but a good linkage hasn't been obtained yet: MPEC.

Exoplanets avoid certain distances from their Suns

So many planets of other sunlike stars have been discovered by now that significant patters are emerging which are not caused by any known selection effects. For example more than 20% of the discoveries by now are Jupiter-like planets on circular orbits with periods of several years: Our own solar system is not that unusual after all anymore. Five of these »other Jupiters« have orbital periods of three years or more, with Tau-1 Gruis, found in Australia, being the latest case.

The overall pattern of orbital period distributions is strange, however: The more exoplanets are discovered, the clearer it becomes that there are some with very short and some with very long periods - but the range of 7 to 50 days is depleted for no apparent reason. The short-period planets very close to their Suns obviously migrated there from further out (where they could form): Some unclear mechanism seems to be forcing them to either move all the way in or stay well away from their stars.

Amateurs urged to join the hunt for exoplanets

While only one extrasolar planet is known so far that crosses the disk of its Sun for observers on Earth (see Update # 158 story 3), this method of detection is by far the easiest one for amateur astronomers to use. The transits in this case are actually so deep that amateurs have detected them - and the challenge is now to find similar regular dips in brightness in other stars for which no planets are known yet. This requires measuring the brightness of a lot of stars again and again with high precision - and even then many of the discoveries may turn out to be just eclipses by accompanying dwarf stars. Spectroscopic observations of the candidate stars (with professional telescopes) over several years will usually be necessary to confirm the planetary nature of any dark object discovered with the transit method.
Strange orbit periods: a paper by Jones & al., Carnegie [SR] and PPARC Press Releases and coverage by SN, Ast., ST, SC.

Exoplanet hunt: TransitSearch Homepage, Ames Press Release, New Sci., SC, Welt, NZ, RP - and a paper by Dreizler & al. showing that many of the exoplanet candidates found by the OGLE transit program are just small stars.

Water masers in exoplanet atmospheres?

Italian radio astronomers have detected water vapor emmission from the direction of stars that may - or may not - have exoplanets: New Sci., AFP, ST, NZ.
Planets should leave ring structures in dust disks around young stars, giving away their existence: Univ. of Utah PR [SR], New Sci., NZ.

All four 8 meter telescopes linked in VLT Interferometer

During the nights of September 15/16 and 16/17, 2002, preliminary tests were successfully carried out during which the light beams from all four VLT 8.2-m Unit Telescopes (UTs) at the ESO Paranal Observatory were successively combined, two by two, to produce interferometric fringes: This marks a next important step towards the full implementation of the VLT Interferometer (VLTI). In the span of only two nights, the four VLT telescopes were successfully "paired" to do exactly this, yielding a first tantalizing glimpse of the future possibilities with this new science machine. While there is still a long way ahead to the routine production of extremely sharp, interferometric images, the present test observations have allowed to demonstrate directly the 2D-resolution capacity of the VLTI by means of multiple measurements of a distant star.

Much valuable experience was gained during those two nights and the ESO engineers and scientists are optimistic that the extensive test observations with the numerous components of the VLTI will continue to progress rapidly. Then, in 2003, the first of the four moveable VLTI 1.8-m Auxiliary Telescopes (ATs) will be put in place on the top of the mountain; together they will permit regular interferometric observations, also without having to use the large UTs. And also in 2003 the first adaptive optics systems for the VLTI will be inserted below the telescopes: By drastically reducing the smearing effects of the turbulent atmosphere this will further "stabilize" the imaging and increase the sensitivity of the VLTI by a factor of almost 100.

ESO Press Release and coverage by Ast.

Astronomers slice and dice galaxies

with the new UKIRT Imaging Spectrometer (UIST) - each slice is then spread out to make a spectrum: JAC Press Release.
A mid-IR image of the Galactic Center has been obtained with Keck: JPL Release [SN], Ast., SR.

Subaru images an aging star - the planetary nebula AFGL 618 has "bullets" & "horns": Press Release.
Hubble views NGC 4319 and Mrk 205 - two galaxies close together in the sky but far apart in space: STScI Press Release, Ast.

Polarization of the Cosmic Background Radiation measured for the first time!

Another milestone in observational cosmology has been reached: The Degree Angular Scale Interferometer (DASI) at the South Pole, which had already been credited with particularly fine measurements of the power spectrum of the Cosmic Microwave Background Radiation (see Update # 223) has now also seen an even more subtle phenomenon, a slight polarization of this afterglow of the Big Bang. The polarization of the cosmic microwave background was produced by the scattering of cosmic light when it last interacted with matter, nearly 14 billion years ago or some 400'000 years after the Big Bang. If no polarization had been found, astrophysicists would have to reject all their interpretations of the remarkable data they have compiled in recent years.

Last year the DASI team precisely measured temperature differences in the cosmic microwave background, further supporting for the cosmic inflation theory. The polarization signal is more than 10 times fainter than the temperature differences that DASI detected earlier: DASI's first discovery came after it collected data for 92 days from 32 spots in the sky, but DASI needed to watch two spots in the sky for more than 200 days to detect the polarization. The discovery opens a new era in cosmic microwave background experiments: Increasingly sensitive detections of polarization will yield many more discoveries - all the way up to the next great step, the detection of polarization stemming from primordial gravitational waves. This signature is probably way too weak even for DASI, but future satellites like ESA's Planck may be able to detect it.

Papers by Leitch & al. and Kovac & al., the DASI Homepage and a Univ. of Chicago Press Release.
Coverage by Science News, S&T, Ast., New Sci., NYT, BBC, NewsFactor, UPI, NZ.

The best power spectra so far

of the microwave background - which also show mysterious structure at very small scale - have been delivered by the Cosmic Background Imager (CBI), already known from Update # 212 story 4: papers by Mason & al. and Pearson & al., the CBI Homepage, an NSF Press Release, coverage by S&T, Ast., New Sci., NYT, WP, BBC, ST, SC - and an old CBI story from BdW.
The Very Small Array has good power spectra, too: Jodrell Bank and Univ. of Cambridge Press Releases and coverage by BBC

ISS Update

Peggy Whitson is now 'science officer' of the ISS while the next mission to the ISS has been delayed by Hurricane Lili to Oct. 7 the earliest.
Status tracking by SN, CBS and FT, the KSC Status of Oct. 1, a JSC Press Release [SN] on Whitson, a KSC Release on the FRR, a NASA Page and Science@NASA on the new shuttlecam, an MSFC Release on the S-1 Truss, an NSBRI PR on ISS medicine and coverage on Oct. 5: WP. Oct. 4: AFP. Oct. 3: AFP (earlier), ZEIT. Oct. 2: SN, AFP, BBC (other story), SMH, NZ, Welt.
Oct. 1: SN, HC (other story), FT, UPI, ST (other story), NYT, Dsc, Taipei Times, Rocky Mtn. News, SC, NZ. Sep. 30: SN (earlier), SD, New Sci., AFP (earlier), AP, UPI, FT, SC, ST (earlier). Sep. 28: Welt. Sep. 27: UPI, RP. Sep. 26: SN, BBC (other story), AFP (earlier), ST. Sep. 25: AFP. SN. Sep. 24: UPI, BBC, KR. Sep. 23: AW&ST, SC, Welt. Sep. 22: AFP. Sep. 21: HC, SD, ST. Sep. 20: What's New, AFP, SC. Sep. 19: ST. Sep. 18: ST, Guardian, HC, SC. Sep. 17: ST (other story), SC (other story). Sep. 16: AFP, AP, SC.
SLI goes after Kerosene engines, not hydrogen-based ones, for the possible shuttle successor: AW&ST.
Vague NASA thoughts about (manned) spaceflight beyond the ISS: SC.

Bright nova in Sagittarius, fading fast

Nova Sgr 2002 # 3 has reached 5th mag. but is dropping rapidly already, to about 8th mag. at the end of September: AAVSO Page, VS Net Page, S&T.

Apollo nature of mystery object confirmed, will leave us in 2003

NASA scientists have confirmed the first known capture of an object into Earth orbit from a Sun-centered orbit (see last Update, lead), thanks to continuing observations of what is most likely the long-lost third stage of a 1969 rocket to the Moon - into which it will most likely not impact: more from Chodas, a JPL Release, Science@NASA, orbit animations and coverage by New Sci., CNN, UPI, Wired, SC.

Color also confirms that the object is manmade: UA [SR] and MIT Releases, Ast., ST, SC, NZ. A lunar impact could have yielded science: SC.

Galileo NavSat crisis unresolved

as Germany & Italy are fighting for leadership, paralyzing the billion-Euro project since many months: AFP, DW.

TDRS-I has finally reached its orbit, after a successful recovery effort made necessary when one of the spacecraft's two propellant fuel tanks did not properly pressurize shortly after its March 8 launch: Boeing Release [SR], SN, SR, ST, SC.

Teledesic in limbo - the satellite communications services company has announced that it has suspended work under its satellite construction contract with Italian satellite manufacturer Alenia Spazio SpA and will significantly reduce its staff as it evaluates possible alternative approaches to its business: Press Release, ST, SC.

Nozomi should be fixed soon

Communications with the Japanese probe enroute to Mars have been restored, and engineers planned to command the spacecraft to reorient itself when it flew past Earth in September: Ast., ST. Five years ago the Mars Pathfinder triumph came to an end: SR.

Mars rovers in doubt? With launch only eight months from now, there are continuing technical problems with NASA's twin 2003 Mars Exploration Rovers that could possibly delay the arrival of one or both rovers at Mars until 2008: Space Daily. Whole world's Mars program in trouble: SD (earlier).

Schedule very tight for Beagle 2 - Mars Express will launch with or without the British lander: New Sci., BBC, ST. Mars plane prototype tested: SC.

The Mars opposition of 2003 will be the best in 57'000 years, calculations by Beish have shown. How its orbit affects the climate of Mars: Brown Press Release, BBC, AFP, Ast., ST, SC. 3D Mars map presented: TU Dresden PM. Did a tough bacterium evolve on Mars? New Sci.

Dynamical evidence for mid-sized Black Holes

of some thousands of solar masses has been found in the cores of two globular star clusters: Carnegie and STScI Press Releases and coverage by S&T, Ast., NSU, New Sci., NYT, WP, CNN, UPI, ST, SC, RP, NZ.

More AGN activity in galaxy clusters than expected for old, gas-poor galaxies: Carnegie and Chandra Press Releases and coverage by Ast., BBC, SC, NZ.

Chandra discovers the history of Black Hole X-ray jets - watching these jets slow down and disappear is like watching a time-lapse movie of the rise and fall of the Bronze Age: Chandra Release, SciAm, FT, SC.

The Crab Nebula, its pulsar and surroundings as a movie: MSFC Press Release, Science@NASA, pictures and coverage by Ast., S&T, WP, CNN, AFP, RP, NZ.

ESA studies missions to discover, fight NEOs

The European Space Agency has launched a new project to seek the best ideas from industry and academia on how to protect the Earth from Near Earth Objects and in particular, to learn more about them: ESA Press Release.

NASA study on asteroid-searching technology due next June - the Office of Space Science has assigned a group of scientists to determine what technology is needed to expand the search for asteroids and other objects that could collide with Earth: AD.

Another hearing about the danger from NEOs took place in Washington, D.C., in front of the House Science Committee on Oct. 3: the Hearing Charter, statements by Weiler, Worden, Burns (with an associated Cornell Press Release), Morrison and Marsden, a statement by Boehlert [SD] and coverage by SR, CNN, Gannett, SC.

Vulcanoid search continues - again the astronomers (see last Update small items) were airborne: CNN.

Stellar occultation by asteroid covered superbly

by scores of amateurs when (345) Tercidina moved across a star on Sep. 17: Results page.

"Ball of fire" hits Sri Lanka - a suspected meteorite burned down trees and scattered particles over a celebrated giant rock: AFP.

New Uranus and asteroid moons have been announced: Ast., BBC, ST, SC.

MUSES-C launch delayed, asteroid rendezvous not affected

The launch of Japan's MUSES-C asteroid mission has been delayed from late this year until May of 2003, but the spacecraft is still scheduled to arrive at asteroid 1998 SF36 in October 2005, returning with a small sample of the asteroid in June 2007: ST.

CONTOUR Challenge winners persevere - without a spacecraft: Ast.

45 years ago Sputnik

started it all: UPI, SC. Also 60 years of V2 in space: NZ. Von Braun's character still being debated: Huntsville Times. Earlier: TIME.

No more N Korean rocket tests? So says Koizumi: AFP.

Chinese TV sat 'hijacking' occured again, said to be traced to Taiwan: Xinhua.

  • Robert Forward, space futurist, dies at 70 - an innovative thinker of space and time, Forward was a persistent voice in opening the space frontier: SR, SC.
  • Moonwalker Aldrin will not be charged for punching a man who claimed that the Apollo landings were faked: BBC, AP, Space Today. Commentary: UPI. Earlier: ABC, SC, SMH, Fox, Guardian.

  • LIGO completes first science run - three interferometers worked in tandem for 2½ weeks to look for gravitational waves: S&T
  • Building the JWST (see last Update story 2) remains a complex task: NYT. Planning for Hubble's demise: NYT.

  • Recent aurora observations show that the solar max isn't over yet: SC, Science@NASA, Ast. Gallery of Aug. 30 to Oct. 2, CENAP. BU named Space Weather Central: BU Press Release [SR], UCAR Release, CSM, AFP. Next solar eclipse promoted heavily in the San Diego Union.

  • How light pollution is affecting not just astronomers but also nature: CSM, Heise.
  • Lumicon is history - the famous company has folded: S&T.

  • Speculation about bacteria in Venus' atmosphere - a biological explanation for alleged chemical abnormalities? New Sci., BBC, ST, NZ. Europa life speculations continue: BBC (earlier), NZ. SETI@Home reaches 4 mio. mark: ST.


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Compiled and written by Daniel Fischer
(send me a mail to dfischer@astro.uni-bonn.de!), Skyweek