And new: An experimental German companion to the CM.
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And here are some NASA Science News on eclipse science and coronal mysteries. |
Update # 146 of September 7th, 1999, at 20:15 UTC
Major Leonid storms predicted for 2001 and 2002Activity in 1999, 2000 less but still quite high, analysis claimsAfter the 1998 experience the meteor theorists have gone back to the drawing boards - and now an Irish and an Australian astronomer claim to have solved all the problems. David Asher from Armagh Observatory and Rob McNaught say that they now completely understand the behavior of the dust streams comet Tempel-Tuttle has left in the solar system and that they can predict future meteor storms with 5 minutes precision in time. And that they know what meteor rates to expect in the sky.The technique involves mapping the fine `braided' structure of the dense dust trails within the Leonid meteoroid stream. Although comet Tempel-Tuttle, the 'parent' of the Leonid stream, passed close to the Earth in 1998, Asher and McNaught predict strong meteor storms in both 2001 and 2002. 1999 and 2000 will be less spectacular, but good. In 1999, observers at European longitudes are favoured, and may see up to 20 meteors a minute (in ideal conditions under a clear, dark sky) at around 2:08 UTC on the morning of November 18th. |
RAS and Armagh Press Releases (alternate version). Where the dust trails are in relation to the Earth. Leonid News Releases at ASTRONET. How the 1998 fireball storm originated in particles 600 years old. Other predictions of coming Leonid shows. A Japanese proposal for the 1999 event. A funny story of how the 1998 event was observed in Fla. |
Chandra activates the first spectrograph and the 2nd detectorOn August 28th the Chandra X-ray Observatory has obtained the first detailled spectrum of the corona of star: 'first light' for the High Energy Transmission Grating, used in conjunction with the ACIS detector that had already taken several interesting images (see last update). The target for the HETG was the star Capella, and the spectrum shows individual X-ray lines from a variety of elements and their ions, such as iron and neon.On August 30th the other detector onboard Chandra, the High Resolution Camera, has looked at its first target, too: the binary system LMC X-1. "These were preliminary test observations," emphasized the principal investigator for the HRC, "But we are very pleased with the results. All indications are that the HRC will perform according to expectations and produce x-ray images of unprecedented clarity." |
HETG info & spectra and an MIT Press Release on the 1st spectrum as well as news coverage by SpaceViews and Astronomy Now. Status Report of Sept. 1st on the first HRC observations. "The Chandra Chronicles" of Aug. 19, Aug. 26 and Aug. 26 again (a safe mode) and Sept. 2. |
India plans X-ray telescope for 2004The Indian Space Research Organization has announced that it will build an X-ray satellite for launch in 2004. The detector will come from the Tata Institute of Fundamental Research in Mumbai (Bombay), the spacecraft itself will be built at an ISRO facility in Bangalore. The detector will target X-rays in the 2 ... 80 keV energy range that other active or planned X-ray observatories don't cover well, the Indians say. (Nature of Sept. 2nd, 1999, p. 9) |
Homepage of the ISRO. |
Proton returns to serviceIn its first launch since July's big crash, a Russian Proton has launched two domestic Yamal communications satellites on September 6th - the ban on launches of this particular rocket type by Kasachstan had been lifted only a week ago. Commercial Proton launches will resume September 26, when a Proton will carry the Lockheed Martin Intersputnik LMI-1 satellite. The July crash had been traced to a faulty weld in a turbopump on the booster's 2nd stage. Stray aluminum particles passed through the weld and caught fire, leading to the destruction of the second stage. |
SpaceViews on the fine launch - and Space.com on trouble with one of the satellites... Why the Proton failed - an ILS release. Somewhat related stories: Mir is in free drift now, awaiting its fate: BBC story. What plans does Energiya really have? Space.com. The final days on Mir as witnessed by a radio amateur in the Netherlands. And why not sell all the stuff on board...? A moderately funny CNN column that has a point, though. |
Magnetic fields are crucial to star formation, observations confirmTheoretical studies have long suggested that magnetic fields should play a vital role in the evolution of interstellar clouds and in the formation of stars - but those studies needed to be compared with observational data. Two basic problems have persisted in our understanding of star formation. First, in a fully formed star, the outward pressure of thermonuclear reactions in the core will balance the inward pull of gravity. In a molecular cloud, however, some other force must be supporting the cloud against its own gravity. Otherwise, all the clouds would have collapsed into stars long ago.The second problem involves transferring excess angular momentum from a developing star. As a molecular cloud coalesces into stars, the material rotates faster and faster. Unless the excess angular momentum is removed, the star will fly apart. Theorists had performed extensive simulations that show how an interstellar cloud might collapse in the presence of a magnetic field: In those studies the clouds were prevented from quickly collapsing and forming stars, and they could get rid of the extra angular momentum, by making the magnetic fields sufficiently strong. To test theory against data the strengths of magnetic fields in 27 interstellar clouds of varying molecular density have now been measured: By comparing each cloud's magnetic energy with its gravitational energy, it turned out that magnetic fields were strong enough to control the rate of collapse and to assist in the star-formation process by providing a means of shedding excess angular momentum. By flinging a small amount of matter outward along the magnetic field lines, the magnetic waves can remove a huge amount of angular momentum, making star formation possible. |
University of Illinois at Urbana-Champaign Press Release. Other astrophysics stories: The discovery of a new type of low-surface-brightness reflection nebula around aging stars has provided important clues about how stars lose mass and form planetary nebulae: University of Illinois Press Release. An X-ray observation of the star Algol has revealed that its huge X-ray explosions take place in structures similar in relative size to those of our own Sun: ESA Science News. Relativistic effects in the vicinity of Black Hole Candidates have been seen by the Rossi satellite, although the interpretation of the data is contentious: Space.com. Colliding Black Holes have been simulated in a computer: MPG Press Release. A new model of the plasmasphere surrounding Earth has been published: NASA Science News. |
The first solar eclipse ever observed from spacewith human eyes was not the one last month, as some reports have claimed. It was an event in Nov. 1966 that Gemini astronauts viewed and photographed, historians say: a rare picture and stories from Encycl. Astronautica and NASA.Daily images of the solar corona from the National Solar Observatory at Sacramento Peak are available again. The solar activity remains very high, as recent flares and CME's show: NASA Science News, CNN, Space.com coverage. 20 years ago: Pioneer 11 at SaturnIt was the first time that a spacecraft visited the ringed planet (Voyagers 1 and 2 would follow in the next 2 years), and despite the lack of a 'real' camera quite a lot was learned: Pioneer pages, an article on Pioneer 11, more on the spacecraft, another mission page and the collected Saturn images by Pioneer 11.What the future Saturn orbiter Cassini saw at the Moon during the Augst Earth encounter is documented in the Cassini Imaging Diary! Coverage by SpaceViews. Still no evidence for lunar waterafter the Lunar Prospector crash - but the data analysis continues: NASA Science News, SpaceViews, SpaceCom and Space Daily coverage. And a Salon story on the Moon...More launch delays for the shuttleare inevitable as the search for damaged wires in the orbiters continues: a status report plus CNN, ABC and SpaceViews coverage. Meanwhile Columbia is getting a facelift during major refurbishment: Space.com. And the shuttles might fly until 2040: BBC story.Worth reading
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'Space mystery' seems solvedThe point source with the inexplicable spectrum that was found during the 2nd Palomar Sky Survey (mentioned in the small items of updates # 134 and 144) is probably a strange variation of a broad-absorption-line quasar, the like of which has been seen only three times before: That's what a new Keck spectrum indicates - updated discoverer's page, another page and a NYT story.Australia's ancient stromatolites - also on Mars?A rare sample of possible terrestrial fossils 3.4 Gyr old has been recovered and brought to a Perth museum - while some see a similar structure on Mars: the Australian Stromatolites Homepage, CNN, MSNBC stories - and the New Scientist on the Mars hypothesis.The Mars Polar Lander has performed a trajectory correction to prepare the landing on Dec. 3rd: SpaceViews. "Mars Week" is coming in October: the Think Mars pages and a CNN story. Plus: an unusual offer to the Mars Society to fly a suborbital payload - Space.com. Space pictures worth looking at
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All other historical issues can be found in the Archive.
The U.S. site of this Cosmic Mirror has been visited
since it was issued (the German site has no counter).
Compiled and written by Daniel Fischer
(send me a mail to [email protected]!), Skyweek
