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By Daniel Fischer Every page present in Europe & the U.S.!
| Ahead | Awards 
The latest issue!
| An experimental German companion. Current mission news: MGS (latest pictures!) + Cassini + Galileo + NEAR |
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NEAR named after Eugene Shoemaker!First X-ray spectra of Eros' surface recorded from 200 km distanceThe satellite conducting the first close-up study of an asteroid has been renamed to honor Dr. Eugene M. Shoemaker, the legendary geologist who influenced decades of research on the role of asteroids and comets in shaping the planets. The Near Earth Asteroid Rendezvous (NEAR) spacecraft, currently orbiting asteroid 433 Eros, will now be known as NEAR Shoemaker. Shoemaker died in a 1997 car accident, while on an annual study of asteroid impact craters in the Australian outback. He was an expert on craters and the impacts that caused them. Shoemaker's work on the nature and origin of Meteor Crater in Arizona in the 1960s had laid the foundation for research on craters throughout the solar system.Meanwhile new science results from the NEAR Shoemaker mission have been announced: After scarcely a month in orbit, the spacecraft is astounding scientists with ever more detailed views of geologic features - and it has started to analyze Eros' chemistry. NEAR's first x-ray detection of Eros has demonstrated the presence of magnesium, iron, and silicon and possibly aluminum and calcium: Their detection was the result of a brilliant solar flare on March 2, when NEAR was 212 km from Eros. That solar explosion made it possible for the spacecraft's x-ray spectrometer to view the asteroid from four times farther away than it was designed to do. The solar x-ray burst caused elements on the asteroid to emit fluorescent x-rays that were measured by the spectrometer - it was only a 600-second window of opportunity but it was a huge bonus for the mission. This detection at the higher orbit gives the scientists confidence in their ability to develop elemental maps when NEAR reaches its operational orbit of 50 km. In the last two weeks, the NEAR multispectral imager has returned more than 2400 images from 200 km altitude, showing chains of craters, numerous boulders as small as 50 meters across, and long ridges that extend for several kilometers across the surface. Conspicuous on many of the crater walls are bright markings, part of the loose, fragmental material on the surface, called regolith. This material appears to vary in properties across the asteroid, perhaps in response to impact cratering events. |
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Amateurs image GRB afterglow with old 12-inch scopeOn March 4, 2000, a small band of amateur astronomers using a 40-year old telescope and a home built CCD camera succeeded in something that few professionals even try: They detected the faint afterglow of a distant gamma-ray burst! Gamma-ray detectors on the NEAR (see sidebar of previous story!) and Ulysses spacecraft first recorded the burst, labeled GRB000301C, on March 1, 2000. Initially, the sky coordinates of the burst were not well known at all: The error annulus from NEAR and Ulysses was a strip about 4.2 arcminutes wide but 180 degrees in length. Then came a second position from the Rossi Timing X-ray Explorer, with an error annulus of 4.2 degrees by 8.7 arcminutes, and by combining the two the error box of the GRB was reduced to a 50 arcminute square.That was just what astronomers needed. The burst was conveniently located near the constellation Hercules, which is high in the night sky and easily seen from northern latitudes this time of year. Bill Aquino and a group of other amateur astronomers with the Buffalo Astronomical Association tried to detect an optical afterglow from the explosion after they had heard about its successful detection at 20th magnitude. The amateurs pointed the astronomy club's 12 inch reflector to the now known coordinates of the burst and accumulated data for two hours: Later when the images were calibrated and summed, there it was, the 20th magnitude fireball just 7 arc seconds from a much brighter 17th magnitude foreground star - the first such detection with a modest amateur telescope. |
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Asteroid to pass Earth in 5 Earth-Moon distances, could reach 14th mag.On March 9, 2000, the 1-meter LINEAR patrol camera in New Mexico picked up a fast-moving asteroid that could threaten Earth at some future date: 2000 EW70 had magnitude 17.5 when first detected, but the asteroid should brighten 20-fold next week as it makes a moderately close flyby, passing only 0.013 Astronomical Units from Earth on March 22nd. 2000 EW70 will then be at about 11h 30m RA and +25 deg. declination near the UMa/Leo border. Small CCD-equipped telescopes can capture trailed images of 2000 EW70 during this period. Any telescope that shows Pluto visually, like 10-inch aperture or larger, should show this object - around closest approach, its unusually rapid motion (about 1 degree per hour!) should be perceptible in a high-power eyepiece. |
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Terra delivers the first Earth views!NASA has on March 10th released the very first engineering images from its $1.3 billion Terra Earth observing satellite. The first-light images show everything from the Mississippi River spilling sediment into the Gulf of Mexico to the delicate geology of the Rift Valley in Ethiopia to a global view of the amount of heat Earth loses to space. "They show that the Terra instruments, with their delicate optics and electronics, made it safely to space," says Terra's project scientist: "The images give us a glimpse on the unprecedented clarity and richness of the data that we anticipate from Terra in the months and years to come."After eleven weeks of on-orbit checkout and verification and a series of orbital ascent maneuvers, the Terra Spacecraft had reached its final orbit on February 23rd. Terra's spacecraft subsystems continue to perform flawlessly, with almost all systems now in their operational science mode. On February 24, the Moderate-resolution, Imaging Spectroradiometer (MODIS) opened the Earth view door during a pass over eastern North America - the acquisition of science data on-board proceeded nominally, and the initial MODIS measurements were successfully downlinked and captured on the ground. Later that morning, the Multi-angle Imaging SpectroRadiometer (MISR) Team opened their instrument cover over central Canada. Again all operations proceeded as planned. As the week was ending, the Clouds and the Earth's Radiant Energy System (CERES) Team had just completed opening the contamination cover on the CERES aft and fore instrument. Once again, the activation of the cover was nominal.The Advanced spaceborne thermal Emission and Reflection Radiometer (ASTER) completed imaging over Japan on February 24, and finally MOPITT's coolers were commanded on and began collecting science data. After a little over two months on-orbit, Terra is beginning to produce spectacular imagery. Operationally, Terra will produce 6 terabytes of data every month, all of which will be available to users for many purposes including science research, applications and education. The first release of Terra Science imagery is expected for mid-April 2000. |
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MTI flies, tests Earth imaging technologyOn March 12th, the Multispectral Thermal Imager satellite has finally made it into orbit after a bizarre range safety issue had caused some delay. The MTI spacecraft will collect images of the Earth in 15 wavelength bands ranging from visible to far IR light at a precision previously only achieved in the laboratory - with the specific task of checking ways to detect hidden weapons factories from space. Also onboard MTI is the High-energy X-ray Spectrometer, a joint project of the U.S. and the Czech Republic to study a rare type of solar flares. With the completion of the MTI mission, the Taurus rocket program extends its record of mission success to a perfect five-for-five. |
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Radar satellite ERS-1 ends mission after 9 yearsHaving given excellent service for nine years, over three times its planned lifetime, the ERS-1 mission was ended on March 10 by a failure in the on board attitude control system. Since its launch in 1991, ESA's first sun-synchronous polar-orbiting mission had made 45 000 orbits, acquiring more than 1.5 million individual Synthetic Aperture Radar (SAR) scenes. ERS-1 SAR images, together with the data from other instruments on board, were delivered to a worldwide community of some 4000 users in science and applications, and surface wind data derived from the scatterometer and altimeter have been supplied to meteorological services worldwide since 1991.The duration of the mission has also meant that scientists have already observed several El Nino phenomena through combined observations of surface currents, topography, temperatures and winds. The measurements of sea surface temperatures, critical to the understanding of climate change, made by the ERS-1 Along-Track Scanning Radiometer are the most accurate ever from space. All these critical measurements are being continued and enhanced by the current ERS-2 mission. The most exciting results from the ERS-1 mission have been in the field of SAR interferometry: The ERS-1 and ERS-2 "tandem operations" demonstrated this technique for various applications and paved the way for missions like SRTM. |
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Higher impact rate in the last 400 Myr - did that help life advance?Scientists analyzing the history of impact cratering on the Moon have reported a surprising increase in the frequency of impacts over the past 400 million years - that may have played a central role in the evolution of life on Earth. The data show that the impact cratering rate had dropped steadily until the unexpected rise when it returned to the same levels as 3.5 billion years ago. The sudden increase coincides with the "Cambrian explosion," a period in which life on Earth took off with a dramatic burst in the number and diversity of species."Although most people assume that impacts cause death and destruction, it is possible that the additional stress of the impacts forced life to become more diverse and flexible," says one of the study's authors: "Just as we stress trees, through pruning, to make them give more fruit, the stress caused by catastrophic impacts may have forced evolution into new directions." The Berkeley team obtained from NASA a gram of lunar soil inside of which they found 155 spherules. The age of each of these tiny spherules was determined with a technique based on the ratios between two argon isotopes. These 155 lunar spherules ranged in size from less than 100 microns to more than 250 microns and came from lunar soil picked up in 1971 by the Apollo-14 mission crew near Mare Imbrium (Sea of Rains), the dark crater that dominates the moon's face. Statistical and chemical analyses showed that the spherules studied came from approximately 146 different craters. Even though it's unknown which crater was the source of each spherule, the distribution of the ages of the spherules from a single lunar site should reflect the age distribution of craters on the Moon. |
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Contracts for ALMA prototype dishes awardedThe European and U.S. partners in the Atacama Large Millimeter Array (ALMA) project have awarded contracts to firms in Italy and the USA, respectively, for two prototype antennas. ALMA is a planned telescope array, expected to consist of 64 millimeter-wave antennas with 12-meter diameter dishes. The European partners contracted with a consortium in Italy on February 21, 2000, for the production of one prototype ALMA antenna. On February 22, 2000, Associated Universities Inc. signed a contract with a California company for the construction of another prototype antenna. The two antennas must meet identical specifications, but will inherently be of different designs. This will ensure that the best possible technologies are incorporated into the final production antennas.Several technical challenges must be met for the antennas to perform to ALMA specifications. Each antenna must have extremely high surface accuracy (25 µm or one-third the diameter of a human hair, over the entire 12-meter diameter). The ALMA antennas must also have extremely high pointing accuracy (0.6 arcseconds). An additional challenge is that the antennas, when installed at the ALMA site in Chile, will be exposed to the ravages of weather at 5000 m elevation - all previous mm-wavelength antennas that meet such exacting specifications as outlined above have been housed within telescope enclosures. |
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MGS gravimetry looks into the crust of MarsA global view of the Martian interior has been generated from gravity measurements with the Mars Global Surveyor radio science experiment and elevation measurements from its Mars Orbiter Laser Altimeter (MOLA): Gravity and topography measurements were combined to reveal the structure of the crust on Mars, which preserves the record of melting of the interior and the heat loss from the planet over time. The new observations reveal that the planet's flat northern lowlands were an early zone of high heat flow that later may have been the site of rapid water accumulation.The crustal thickness map shows that, as for Earth, Mars has two distinct crustal provinces: Beneath the rough southern highlands and Tharsis volcanic province the crust, estimated at 80 km thick, thins progressively from the South pole toward the North. In contrast, the northern lowlands and Arabia Terra region of the southern highlands have a crust of uniform thickness, about 35 km deep. The crustal structure accounts for the elevation of the Martian northern lowlands, which controlled the northward flow of water early in Martian history, producing a network of valleys and outflow channels. The new gravity-field data suggest that the transport of water continued far into the northern plains. The gravity shows features interpreted as channels buried beneath the northern lowlands emanating from Valles Marineris and the Chryse and Kasei Valles outflow regions. The features are about 200 km wide and over 1600 km long, with characteristics that can be explained by water flow on the surface or in a submarine environment, later buried by sediments. The large size of these channels implies that any bodies of water in the northern lowlands could have accumulated rapidly: The now-buried channels may represent the means for filling an early ocean. The gravity and topography also provide information on the cooling of Mars over time, which bears on the early climate and history of water. The observations suggest that the northern lowlands was a location of high heat loss from the interior early in Martian history, probably due to a period of vigorous convection and possibly plate recycling inside of Mars - and the high heat-loss zone corresponds to the part of Mars proposed to have been the site of an ancient ocean. The rapid transport of heat to the surface in this region would have released onto the surface and into the atmosphere gases and water or ice trapped in the interior: That may have been the period when Mars had a warmer climate, liquid water flowed on the surface, and the planet's surface was shielded from the solar wind by a global magnetic field. |
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SeaLaunch fails - first ICO satellite destroyed!The March 12 flight of the Sea Launch Zenit 3SL rocket has been a failure: The Zenit rocket veered off course and crashed into the Pacific Ocean, 4300 km downrange from the Odyssey launch platform, destroying the first ICO mobile communications satellite. It would have been the first satellite for the company that is still in bankcruptcy but was saved by Craig McCaw who wants to use the constellation for medium-speed data transfer: Spaceflight Now's Mission Status Center, Fla. Today, AP, SpaceViews, BBC, Space Daily, Fla. Today, ABC, Spaceflight Now, BBC again. When it still looked like a success: Space.com ...Study raises safety matters for the ShuttleEfforts to cut the costs of operating the space shuttle are eroding safety, and NASA needs to immediately take a more active role in shuttle operations by private contractors to reduce risks, an independent study group has concluded - but the shuttles may continue flying in the meantime: the Report, its Executive Summary and Recommendations; coverage by CNN, NYT, Fla. Today, Houston Chr., Space.com, Discovery, RP.Unpublished NASA report says all-woman flight isn't necessary - critics have said NASA has delayed publishing the report, dated Sept. 30, because it does not provide the hoped-for scientific justification for the project NASA had talked about: the report, UPI, earlier reports.
Another Proton flies, tooA Proton rocket with a Russian communications satellite was successfully launched on March 12th from the Baikonur cosmodrome, carrying an Express-A communications satellite - a Proton carrying another Express-A had crashed in October after takeoff from Baikonur: Space.com, Fla. Today, Spaceflight Now, SpaceViews.Kazakhstan may demand space launch fee from Russia - a share of profits from commercial launches from the Central Asian state's Baikonur Cosmodrome: Space.com. The heliosphere is tiltedData from Hubble's long-removed Goddard High Resolution Spectrograph (GHRS) and Voyager measurements have now allowed to locate the interstellar bow shock and have also shown that the nose of the heliosphere points 12 degrees away from the direction from which the local cloud is approaching: ESA Science News, Space.com = EZ, Discovery.Cluster quartet ready for trip to Baikonur - the fourth and final Cluster II satellite (FM 5) has completed its rigorous series of environmental tests: ESA Science News, RP. |
Poor communication, teamwork doomed the MCOThe final investigation report furthers the devastating early analysis of the management mistakes inside the Mars Climate Orbiter project published last November (see Update # 157 story 2): the report (also a second one on the problems of the faster-better-cheaper approach), NASA's response, AFP, Space.com (also details on the MCO and FBC reports), ABC, Spaceflight Now, Fla. Today, CNN, NYT, Discovery, RP, Fla. Today commentary.Mars rovers - what NASA has in store for future missions: Space.com. More on the future of the NASA Mars program and speculation on the MPL loss (the respective report is delayed) in a Discovery Feature. Gravity Probe B faces crucial test this summerThe half billion-dollar space mission designed to prove Einstein right or wrong is struggling with technical difficulties, rising costs and a receding launch date - NASA managers say they will give the program until summer to shape up before considering whether or not to cancel the effort: Space.com.China to send space capsule to Mir?Another dramatic twist to the mysterious saga of China's space program - and the fate of the old space station that just wouldn't die: Space.com.Was the maiden flight of the Chinese space capsule planned to be manned, with the mission changed to unmanned because the performance of "Shenzhou" could not be guaranteed? Space Daily. Russian actor may not fly to Mir - the required money for the voyage is still absent from certain Russian coffers, officials have said: AP, Space.com. Boeing offers to pay for the lost ISS tanks but can't figure out how exactly they had disappeared: SpaceViews, Space.com, Space Daily.
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Compiled and written by Daniel Fischer
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