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By Daniel Fischer Every page present in Europe & the U.S.!
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The latest issue!
| A German companion! (SuW version) Current mission news: MGS (latest pictures!) + Cassini + Galileo + NEAR |
Despite the breaking up of its nucleus, comet C/2001 A2 was a nice naked-eye view for the S hemisphere in June (with up to 3.5 mag.) and has now returned to Northern skies, down to 5.0 mag.: AstroNet, BBC, SC, Astronomy, brightness estimates collected by ICQ and JPL and pictures from Essen, by Horn, from July 4, June 30 and June 20.
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Cosmology satellite MAP launched, on deep space journeyThe Microwave Anisotropy Probe (MAP) lifted off on schedule at 19:46 UTC on June 30 aboard a Delta II rocket from Cape Canaveral Air Force Station. About 90 minutes later MAP separated from the third stage, deployed its solar arrays and began its journey to answer fundamental questions about the history, content, shape and fate of the Universe by studying the fluctuations in the Cosmic Microwave Background Radiation in great detail. The observations will begin once MAP reaches its L2 orbit, L2 being the second Lagrange point of the Sun-Earth system. L2 is four times farther from the Earth than the Moon in the direction opposite the Sun, or about 1.5 mio. km from Earth, and MAP is the first spacecraft to use an orbit around the L2 point as its observing station.MAP is currently in a highly elliptical Earth orbit. In approximately one month, MAP will execute a gravity-assist swing past the Moon and then travel for two months to get to its L2 orbit. This particular trajectory is designed to minimize the use of fuel. From L2, MAP will have an unobstructed view of the sky, and will be free from near-Earth disturbances such as magnetic fields and microwave emission for its two years of science observations. It will take about 18 months to build up a full-sky picture and perform the analysis. While the angular resolution of 1/4 degree is not better than what recent balloon and South Pole experiments have achieved, MAP's main promise is a global CMBR map of this resolution and - thanks to the L2 position far from the Earth - also much less noise. |
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The solar "neutrino problem" is gone!The Canadian Sudbury Neutrino Observatory (SNO) has provided the first direct evidence for neutrino oscillations and also solved the 30-year old "solar neutrino problem!" Electron neutrinos are emitted in vast numbers by the nuclear reactions that fuel the Sun, and since the early 1970s, several experiments have detected neutrinos arriving on Earth - but they have found only a fraction of the number expected from detailed theories of energy production in the Sun. This meant there was something wrong with either the theories of the Sun or the understanding of neutrinos. The SNO is the first detector that can distinguish between electron neutrinos and the other neutrino flavors (muon and tau) - and it turns out that not all neutrinos detected from the Sun are of the electron flavor.This is the first direct evidence that they change as they travel from the core of the Sun to the Earth. Furthermore the new data show that the original number of electron neutrinos produced in the Sun is just as high as predicted by detailed solar models - not exactly a surprise as these models had long been verified independently through observations of the Sun's oscillations (helioseismology). The existence of neutrino oscillations had already been established in a somewhat more indirect way in 1998 (see Update # 82), but now it's clearer than ever and really establishes that neutrinos have a mass. The sum of the masses of all three types must lie in the interval 0.05 to 8.4 electron volts: This means that neutrinos can contribute at most 18% of the critical matter density of the Universe, and in all likelihood their contribution is much lower. |
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Lone planets wandering through a globular cluster?The Hubble Space Telescope has uncovered tantalising clues to what could potentially be a strange and unexpected population of wandering, planet-sized objects in the globular star cluster Messier 22. The evidence: six unusual microlensing events which occur when a background star brightens momentarily as a foreground object drifts by. The unusual objects thought to cause these events are far too dim to be seen directly, but instead were detected by the way their gravitational field amplifies light from a distant background star in the huge central bulge of our Galaxy. In 1999 about 83,000 stars were monitored, detecting one clear microlensing event caused by a normal dwarf star in the cluster (about one-tenth the mass of our Sun). As a result of gravitational lensing, the background star appeared to grow 10 times brighter and then returned to its normal brightness over a period of 18 days.In addition to this microlensing event, however, there were six even more interesting, unexpectedly brief events where a background star jumped in brightness by as much as a factor of two for less than 20 hours before dropping back to normal brightness. This means that the microlensing object must have been much smaller than a normal star. These microlensing events were unusually brief, indicating that the mass of the intervening object could be as little as 80 times that of Earth. Objects this small have never before been detected by microlensing observations. If these results are confirmed by follow-up Hubble observations, the bodies would be the smallest celestial objects ever seen that are not orbiting any star. So what are they? Theoretically they might be planets that were gravitationally torn away from parent stars in the cluster. However, they are estimated to make up as much as 10 percent of the cluster's mass - too numerous to be wandering, 'orphaned' planets. The results are so surprising the astronomers caution that these preliminary observations must be confirmed by follow-up Hubble observations. Additional observing time has already been requested, this time covering a shorter interval with much higher time resolution. If verified, these dark denizens could yield new insights about how stars and planets formed in the early Universe. (Sahu et al., Nature 411 [June 28, 2001] 1022-4) |
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New mission scenario to rescue Huygens dataESA and NASA have identified a new mission scenario in order to solve the Huygens radio communications problem and fully recover the scientific return from the Cassini-Huygens mission to Saturn and its giant moon Titan. After six months of investigations and analysis by a Joint ESA/NASA Huygens Recovery Task Force (HRTF), senior management from the two space agencies and members of the Cassini-Huygens scientific community have endorsed several modifications to the mission. These will allow a return close to 100% of the Huygens science data, with no impact on the nominal prime Cassini tour after the third Titan encounter. In order to ensure that as much data as possible is returned from the probe, the Huygens Recovery Task Force proposed a new schedule for Cassini's first orbits around Saturn.The agreed scenario involves shortening Cassini's first two orbits around the ringed planet and inserting an additional orbit which provides the required new geometry for the Huygens mission to Titan. Under the new scenario, the arrival at Saturn on 1 July 2004 remains unchanged. However, Cassini's first flyby of Titan will now occur on 26 October, followed by another on 13 December. The Huygens Probe will be released towards Titan on 25 December 2004, for an entry into the moon's atmosphere 22 days later, on 14 January 2005, seven weeks later than originally planned. In order to reduce the Doppler shift in the signal from Huygens, the Cassini Orbiter will fly over Titan's cloud tops at a much higher altitude than originally planned - 65 000 km instead of 1200 km. This higher orbit has the added advantage that Cassini will be able to preserve the four-year baseline tour through the Saturn system, by resuming its original orbital plan in mid-February 2005. |
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Rapid X-ray heartbeat may indicate a new kind of objectThe X-ray satellite XMM-Newton may have discovered a new kind of celestial object: a very luminous soft X-ray source that is pulsating extremely rapidly in the central region of the Andromeda galaxy. This new source (referenced as XMMU J004319.4+411758) could be a white dwarf, a remarkably dense and compact star, with an extremely short orbital period sucking matter from a secondary star. However in this case the object would have to be very close by because a very short orbital period means a very small mass-losing star and such binary systems cannot be very bright. It could only appear bright if it were nearby, and this is unlikely because there are very few stars between us and M31. A more plausible explanation is that the pulsation indicates that the white dwarf possesses a magnetic field large enough to modulate the X-ray emission, yet not large enough to lock the star's spin and rotation periods. |
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Kuiper Belt Object found with 1000 to 1200 km diameterAn icy planetary body orbiting the Sun has been discovered beyond Neptune in the Kuiper Belt roughly equal in size to Pluto's moon Charon. It is intrinsically the brightest Kuiper Belt Object found so far, though the exact diameter of 2001 KX76 depends on assumptions about its albedo. Traditional assumptions make it the biggest by a significant amount, while others make it larger by at least 5 percent. Assuming an albedo of 4 percent, 2001 KX76 would have a diameter of approximately 1270 km, bigger than Ceres, the largest known asteroid. For comparison, Pluto's moon Charon has an estimated diameter of 1,200 km. Earlier this year, a Kuiper Belt Object (KBO) called 20000 Varuna was announced with an estimated diameter of 900 kilometers, based on a calculated reflectivity of 7 percent: Applying this albedo to 2001 KX76 gives it a diameter of roughly 960 kilometers. |
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Clear skies for long solar eclipse in AfricaAll of southern Africa - and most of Madagascar - was clear on the afternoon of June 21 when the first total solar eclipse of the new millennium raced across the continent. The majority of observers had congregated in Zambia: Some flew in for just a few hours on chartered planes (e.g. from Austria), others stayed close to Lusaka (the only major city in the path of totality), and a few ventured further into the countryside, experiencing not only a nice eclipse (with a corona similar to 1999, though with fewer large prominences) but also 'The Real Africa' first-hand. Now many are wondering: Should we return to this exciting world for the next total eclipse on Dec. 4, 2002 (in the middle of the rainy season) or head to Australia instead, which will be met by the lunar umbra just before sunset? |
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ISS UpdateJuly 12 has been confirmed as the new launch date for Atlantis' 11-day mission, with liftoff planned for 09:04 UTC. Delayed because of troubles with the ISS' new robotic arm, the flight will deliver the $164 million Joint Airlock to the outpost which will serve as the staging area for U.S. and Russian spacewalks.Energia, KSC and Ames Releases, Science@NASA about the airlock. | Status # 22, 21, 20, 19, 18, 17, 16 and coverage of July 9: SC, SN, FT. July 8: SC. July 6: SC. July 5: Aerosp. Daily. July 3: AN, CNN. July 2: SN, AD, SC ( other story), SPIEGEL. June 30: FT, ST, Science Status. June 29: SC ( other story), FT, ST. June 28: FT, ST, SC, SN. June 27: FT, ST, AD, SN, AFP, ASGSB Alert. June 26: FT, SC ( other story), Tito Testimony, Kodak Release. June 22: FT (other story). June 21: SN. June 19: HC, SC. June 17: FT special. June 15: FT, SC (other story), ST. June 14: SN, Zap2it, SC. June 13: SC. June 12: FT. June 11: Interfax. June 9: ST. June 8: SC, SPIEGEL. June 7: SN, SC ( other story), WELT. |
Global dust storm in progress on Mars!Since late June increasing dust activity has been observed on Mars, with the dust cloud visible from Hesperia to Hellas and then covering most of the planet: CMO Reports and pictures.The best HST image of Mars yet was obtained on June 26: STScI, SC, CNN, BBC, Astronomy, SPIEGEL. Mars came pretty close to Earth on June 21: Science@NASA, JPL Release, SciAm, Astronomy, CNN, SC. Simulated views: MSSS. Mysterious flashes seen on Mars could be related to ice clouds - and were actually predicted: IAUC #7642, history, SPIEGEL. Mars lava mingled with ground iceand formed "rootless cones" - they thus present evidence for water near Mars' equator just 10 million years ago: UA News [SN, SR], NSU, PSRD, SC, AFP, SPIEGEL. Still more wet Mars news by PSRD, AFP, ST, AP.Hunting dust devils on Mars: an interview. Similar research on Earth: SC. Defrosting dunes: JPL. Ten Mars Scout candidates selected for missions from 2007 onwards: NASA Release, JPL Release, FT, SC, Astronomy, AN, SR. Netlander: WELT. Mars Express developments: SD, SN, ESA Science News, again. Mars Odyssey fine-tunes path, is doing fine: JPL Release, Status, SC. HESSI launch delayed indefinitelyThe solar satellite will only be allowed to fly on its Pegasus booster when the problems that seem to have led to the loss of the first X-43A experimental vehicle have been understood and resolved fully: KSC Release, Homepage, AN, ST, FT. Earlier: SN (earlier), Science@NASA, SC. The X-43A investigation: SD, SC.Planetary Society solar sail repaired, might still fly in space this year: Media page, SN, ST. First H2-A launch set for August 25, an upgraded version of Japan's H-2 booster that was retired after back-to-back launch failures in 1998 & 1999: ST, SC, AFP. New quasar redshift records (z=6.0 and 6.2)have been set, thanks to the Sloan Digital Sky Survey; the previous record holder for a redshift measured directly was z=5.8 (see Update # 186). SDSS discoveries affect our knowledge of the Universe near and far alike: Press Release, AP, SPIEGEL.New map of the "nearby" Universe reveals large-scale structure of galaxies, based on the recently completed infrared survey of the entire sky called 2MASS: Press Release. 2dF data set released to astronomers around the world: paper by Colless & al., Homepage, BBC. Acoustic waves detected in Alpha CentauriTiny oscillations in this solar-twin star have been unambiguously detected by Swiss astronomers using the CORALIE spectrometer on the Swiss 1.2-m Leonard Euler telescope at the ESO La Silla Observatory - the new measurements show that Alpha Cen pulsates with a 7-minute cycle, very similar to what is observed in the Sun: ESO Press Release, BBC, CNN.The first science results from the Gemini North telescope range from massive young star clusters swaddled in a dust cocoon 1 billion km wide to intriguing structural details in a circumstellar disk around a nearby binary star system: NOAO Press Release [SR]. OH megamasers from colliding galaxies50 peculiar extragalactic objects called OH megamasers, found with the radio telescope at Arecibo Observatory, could yield major clues in understanding the physics behind the formation of galaxies - the collision of two galaxies and the merger of their nuclei lead to a high compression of the gas, a star formation rate increase and an environment that favors the maser process: Cornell Press Release.Hubble pics show single stars in distant galaxy - for the first time individual stars have been resolved in the infrared over 30 mio. lightyears distance: U CA Davis Release. A future for Buran?Russia plans to reassert itself as a major power in space by resurrecting the Buran space shuttle: New Scientist [SR], SC. Russia's space program slowly regaining shape? SC. |
GRB host galaxy seen with radio telescopePreviously, gamma-ray-burst host galaxies have been seen with optical telescopes, but the detection of the galaxy in which GRB 980703 exploded with the VLA provides new clues about the nature of the galaxy itself - such as a very high star formation rate: NRAO Press Release.Adolescent interstellar cloud poised to make star-forming debut - it could be the first ever to be detected in the transition between atomic and molecular states: NRAO Press Release, SC. Brightest quasars inhabit galaxies with star-forming gas clouds - the most luminous nearby optical quasar galaxies have massive reservoirs of interstellar gas much like the so-called ultraluminous infrared galaxies (or ULIRGs): CalTech Press Release. Lasers show stars are larger than thoughtUsing a novel observational technique an 85-year-old Nobel laureate has mixed lasers with starlight and, with a sprinkling of luck, discovered that some old stars are larger than expected: SC.Two Pluto mission studies selected by NASANASA has selected two proposals for detailed mission feasibility studies as candidates for a Pluto-Kuiper Belt (PKB) mission - but the President's FY 2002 budget request does not contain any development funding for a Pluto mission: NASA Release [SD, SR], JPL Release, SC, ST, Daily Camera, AN, SN. Extremely close Pluto appulse with a star, possible occultation discovered: JPL.Rosetta launch on an Ariane 5 confirmed for January 2003: ESA Science News. The mission's goals: Astrium Release, SC. The CONSERT experiment on Rosetta: ESA Science News. Comet mission Contour launches 1/2 year earlier: Cornell Release. And Deep Space 1 is closing in on Borrelly: Mission Log. NASA approves Mercury mission MESSENGER: NASA Release, AN, ST, AFP, SC. Largest-ever ESA contract awarded to build astronomy satellitesThe largest contract ever in the history of European space astronomy has been awarded by the European Space Agency to an industrial consortium led by Alcatel Space Industries for the manufacture of two ESA astronomy satellites, the Herschel Space Observatory and Planck - the contract is valued at 369 million Euros: ESA Science News.Deep Space Network braces for a flurry of activityNASA is already preparing its deep space communications network for a crunch period beginning in November 2003, when the U.S., Europe and Japan all will have missions arriving at Mars, while at the same time Stardust will be encountering a comet and another comet mission named "CONTOUR" will launch: Science@NASA, SC.First focused high-energy X-ray images capturedUsing a balloon telescope containing unique X-ray mirrors, a team from NASA's Marshall Space Flight Center has obtained the world's first focused high-energy X-ray images of any astronomical object: HERO Homepage, MSFC Press Release, Science@NASA, pictures, SC.Australia to host giant radio telescope? Australia is a major player in the planning consortium for the Square Kilometre Array: CSIRO Release. 'Luneburg lens' delivered: CSIRO Release, SC. Lovell Telescope gets metal upgrade - piece by piece the old surface of the British radio telescope is replaced with one that is more accurate: BBC. Improving the Hobby-Eberly Telescope with a special Segment Alignment Maintenance System: MSFC Release. Mount Wilson Observatory - "one of the shrines of modern astronomy": Reuters, NYT. ESA will not save Russia's Spektrum-X-Gammaastronomy satellite - there just isn't enough money available, the Science Programme Committee has found in late May: Space Science Newsletter # 40.
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Compiled and written by Daniel Fischer
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