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Архив RU.SPACE.NEWS за 24 июля 1998

Дата: 24 июля 1998 (1998-07-24) От: Alexander Bondugin Тема: Researcher Presents Case For Liquid Water On Mars Привет всем! Вот, свалилось из Internet... Reseacher presents case for liquid water on Mars A Biospherics news release July 21, 1998 Dr. Gilbert V. Levin, Mars Viking Experimenter, reported on his study that water exists on the Red Planet's surface in sufficient amounts to sustain microbial life. His findings were presented to the Annual Meeting of the Society of Photo-Optical Instrumentation Engineers (SPIE) in San Diego on Monday. Dr. Levin, President of Biospherics in Beltsville, Maryland, shared authorship with his son, Dr. Ron Levin, physicist at the MIT Lincoln Laboratory in Boston. The importance of the study, Dr. Gilbert Levin said, is that it clinches the case that his Viking LR experiment found life on Mars in 1976, a conclusion that he announced in 1997. In recent years, all arguments against the LR experiment had been eliminated except the claim that there was no life-requiring liquid water on the surface of the Red Planet. Last February, in discussing Mars against the background of startling new findings of life in hostile Earth environments, Dr. Wesley Huntress, NASA's Associate Administrator for Space Science, said: "We used to think that life was fragile, but wherever liquid water and chemical energy are found, there is life. There is no exception. Life may be a cosmic imperative." Dr. Levin described a dynamic daily cycle on Mars in which the extreme cold of the Martian atmosphere greatly restricts its ability to hold water vapor. Thus, the scant water vapor on Mars is forced down to the surface, where it is deposited in frozen form. As the sun rises, the ice melts, but its evaporation is restricted by the low vapor capacity of the overlying cold atmosphere. Levin cited Pathfinder's results to show that the atmosphere immediately above the surface warms considerably, equaling a spring day on Earth, but, just a couple of feet above the surface, temperatures are sub-freezing. The warmed surface layer of air absorbs water vapor until saturated. No more water can then evaporate from the surface, and the ice remaining there melts into liquid water. As the sun mounts, the temperature of the atmosphere above the surface warms sufficiently to permit any remaining water and ice to evaporate. However, during this daily cycle, the soil has been moistened with enough water to sustain microorganisms. Dr. Levin explained: "Based on Viking and Pathfinder data, and consistent with the principles of thermodynamics of the triple point of water, a model has been created for a diurnal water cycle on Mars. The model predicts the presence of several tenths of a percent to one percent water moisture in the topmost layer of the surface material over large regions of Mars. Images taken by the Viking Lander cameras show nightly deposits of surface water frost, even snow, verifying the prediction of the model. Terrestrial experiments in natural environments, including the Death Valley sand dunes of California, demonstrated that the amount of soil water moisture predicted by the model is sufficient to sustain survival and growth of common soil microorganisms." Levin states: "This model removes the final constraint preventing acceptance of the biological interpretation of the Viking LR Mars data as having detected living microorganisms in the soil of Mars. It comes at a time when a growing body of evidence from the Earth and space are supporting the presence of life not only on Mars, but on many celestial bodies." As a result, Levin pressed for early Mars biology missions, none of which is currently planned by NASA, to verify and study life forms, and for caution in current plans for returning a Mars sample to Earth. Under its motto, "Technologies for Information and Health," Biospherics' mission is to provide guidance and products to improve the quality of life. In addition to its BioTechnology unit, the Company offers telecommunications and database management information, and proprietary environmental, food and medical innovations. For more information, visit the Biospherics Web site http://www.biospherics.com/mars/spie2/spie98.htm Hа сегодня все, пока! =SANA=

Дата: 24 июля 1998 (1998-07-24) От: Alexander Bondugin Тема: Mars Global Surveyor Update - July 17, 1998 Привет всем! Вот, свалилось из Internet... Mars Global Surveyor Flight Status Report Friday, 17 July 1998 As of today, the Mars Global Surveyor spacecraft has completed nearly seven weeks of science collection operations since the end of solar conjunction in late May. During that month, the flight team suspended science operations because Mars passed behind the Sun as viewed from the Earth. This geometry physically blocked radio communications with the spacecraft. Since the end of conjunction, Surveyor has completed over 100 revolutions around the red planet and has transmitted almost two gigabytes of scientific information back to Earth. Some of the latest images released from this summer's science observations include pictures of a crater that may have contained a lake long ago in Martian history. Other highlights include laser topography measurements of the North Pole, and analysis of radio signals sent from the spacecraft to aid the understanding of the gravity field in the northern hemisphere. Over the remainder of this summer's science operations, investigators on Earth will receive their data in less time after transmission as the Earth to Mars distance decreases from its June 22nd maximum of 234 million miles (377 million kilometers). At that distance, 2.5 times greater than Earth's distance to the Sun, radio signals from the spacecraft took 21 minutes to reach Earth. This time delay will gradually decrease to just under five minutes by next May. Currently, members of the flight team are preparing for upcoming activities in the late summer and fall months. In late August and early September, Surveyor will pass within a thousand miles of the Martian moon Phobos. This satellite orbits the red planet once every 7.7 hours and is a potato-shaped rock about the size of Manhattan. During the close approaches, several of the science instruments are scheduled to make observations of the moon. During August, the flight team will also begin training for the next phase of aerobraking. This phase will begin in mid-September and last until February 1999. Over the course of those four months, Surveyor will repeatedly fly through the upper Martian atmosphere and use air resistance to gradually shrink the size of the orbit. The goal is to reduce the period from its current value of 11.6 hours to just under two hours. Global mapping operations from this two-hour orbit will begin in March or April of next year. After a mission elapsed time of 617 days from launch, Surveyor is 232.68 million miles (374.46 million kilometers) from the Earth and in an orbit around Mars with a high point of 11,111 miles (17,881km), a low point of 109.6 miles (176.4 km), and a period of 11.6 hours. The spacecraft is currently executing the P430 command sequence, and all systems continue to perform as expected. The next status report will be released sometime in August. Status report prepared by: Office of the Flight Operations Manager Mars Surveyor Operations Project NASA Jet Propulsion Laboratory California Institute of Technology Pasadena, CA 91109 Hа сегодня все, пока! =SANA=

Дата: 24 июля 1998 (1998-07-24) От: Alexander Bondugin Тема: New Mars Global Surveyor Image Of Valles Marineris Привет всем! Вот, свалилось из Internet... NEW MARS GLOBAL SURVEYOR IMAGE OF VALLES MARINERIS A new image taken by the Mars Global Surveyor spacecraft of Valles Marineris is now available on the MGS website: http://mars.jpl.nasa.gov/mgs/msss/camera/images/7_20_98_marineris_rel/index.ht ml More than 4,000 km in length, Valles Marineris is the largest canyon system in the solar system. Image caption is appended below. Ron Baalke Mars Global Surveyor Mars Orbiter Camera Mars Orbiter Camera (MOC) High Resolution Images Western Candor Chasma, Valles Marineris Mars Global Surveyor Mars Orbiter Camera Release: MOC2-59a, -59b, -59c, -59d, -59e Mars Global Surveyor Mars Orbiter Camera Image ID: 568534375.8403 P084-03 (C, below); 576779012.23304 P233-04 (D, below); 577575955.25205 P252-05 (E, below). (A) [Image] 270 KByte GIF image (A) The Valles Marineris trough system is more than 4,000 kilometers (2500 miles) in length. Each "Chasma" that makes up the trough system is labeled above (e.g., Ophir is "Ophir Chasma"). White box indicates the location of the context image shown below in (B). Three MOC images within this box are presented in (C), (D), and (E). Picture is a mosaic of Viking Orbiter images from the U.S. Geological Survey. North is up. (B) [Image] 113 KByte GIF image (B) Western Candor Chasma. Small white boxes indicate the approximate locations of each of the MOC images shown below. Each box is labeled with an image number--8403 is the third image from Mars Global Surveyor orbit 84 (shown in (C), below); 23304 is the fourth image from orbit 233 (D, below); and 25205 is the fifth image from orbit 252 (E, below). Picture is a mosaic of Viking Orbiter images from the U.S. Geological Survey. North is up. (C) [Image] 136 KByte GIF image (C) Layers in western Candor Chasma northern wall. MOC image 8403 subframe shown at full resolution of 4.6 meters (15 feet) per pixel. The image shows an area approximately 2.4 by 2.5 kilometers (1.5 x 1.6 miles). North is up, illumination is from the left. Image 8403 was obtained during Mars Global Surveyor's 84th orbit at 10:12 p.m. (PST) on January 6, 1998. (D) [Image] 291 KByte GIF image (D) Layers exposed near the middle of western Candor Chasma. MOC image 23304 subframe shown at 10.7 meters (35 feet) per pixel. Two layered buttes (upper right and lower right) and a layered or stepped mesa (center right) are shown. The image covers an area approximately 5.5 by 5.5 kilometers (3.4 x 3.4 miles). North is approximately up, illumination is from the lower right. Image 23304 was obtained during Mars Global Surveyor's 233rd orbit at 9:23 a.m. (PDT) on April 11, 1998. (E) [Image] 273 KByte GIF image (E) Massive (non-layered) material exposed in central Candor Chasma. MOC image 25205 subframe shown at 11.7 meters (38.4 feet) per pixel resolution. Image shows the southern tip of a massive "interior deposit" that points like a giant tongue from Ophir Chasma (to the north) down into the center of Candor Chasma. The ridged and grooved bright unit is the "interior deposit". South of this ridged unit is a low elevation surface mantled by dark dunes and sand. Image covers an area approximately 5.7 by 5.7 kilometers (3.5 x 3.5 miles). North is approximately up, illumination is from the lower right. Image 25205 was obtained during Mars Global Surveyor's 252nd orbit at 2:45 p.m. (PDT) on April 20, 1998. You may need to adjust the images for the gamma of your monitor to insure proper viewing. Note: This MOC image is made available in order to share with the public the excitement of new discoveries being made via the Mars Global Surveyor spacecraft. The image may be reproduced only if the image is credited to "Malin Space Science Systems/NASA". Release of this image does not constitute a release of scientific data. The image and its caption should not be referenced in the scientific literature. Full data releases to the scientific community are scheduled by the Mars Global Surveyor Project and NASA Planetary Data System. Typically, data will be released after a 6 month calibration and validation period. Click Here for more information on MGS data release and archiving plans. CAPTION One of the most striking discoveries of the Mars Global Surveyor mission has been the identification of thousands of meters/feet of layers within the wall rock of the enormous martian canyon system, Valles Marineris. Valles Marineris was first observed in 1972 by the Mariner 9 spacecraft, from which the troughs get their name: Valles--valleys, Marineris--Mariner. Some hints of layering in both the canyon walls and within some deposits on the canyon floors were seen in Mariner 9 and Viking orbiter images from the 1970s. The Mars Orbiter Camera on board Mars Global Surveyor has been examining these layers at much higher resolution than was available previously. MOC images led to the realization that there are layers in the walls that go down to great depths. An example of the wall rock layers can be seen in MOC image 8403, shown above (C). MOC images also reveal amazing layered outcrops on the floors of some of the Valles Marineris canyons. Particularly noteworthy is MOC image 23304 (D, above), which shows extensive, horizontally-bedded layers exposed in buttes and mesas on the floor of western Candor Chasma. These layered rocks might be the same material as is exposed in the chasm walls (as in 8403--C, above), or they might be rocks that formed by deposition (from water, wind, and/or volcanism) long after Candor Chasma opened up. In addition to layered materials in the walls and on the floors of the Valles Marineris system, MOC images are helping to refine our classification of geologic features that occur within the canyons. For example, MOC image 25205 (E, above), shows the southern tip of a massive, tongue-shaped massif (a mountainous ridge) that was previously identified as a layered deposit. However, this MOC image does not show layering. The material has been sculpted by wind and mass-wasting--downslope movement of debris--but no obvious layers were exposed by these processes. Valles Marineris is a fascinating region on Mars that holds much potential to reveal information about the early history and evolution of the red planet. The MOC Science Team is continuing to examine the wealth of new data and planning for new Valles Marineris targets once the Mapping Phase of the Mars Global Surveyor mission commences in March 1999. ------------------------------------------------------------------------ Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO. Hа сегодня все, пока! =SANA=

Дата: 24 июля 1998 (1998-07-24) От: Alexander Bondugin Тема: New Marathon! Привет всем! Вот, свалилось из Internet... Every amateur astronomer has heard of the Messier Marathon, the one night event around the night of March 21. Now there's a new marathon that anyone (in the northern hemisphere) with a pair of binoculars can participate in. To find out how this came about and what objects are on the list (no Messier objects at all) then visit the ALL NEW eFOCUS at: http://www.geocities.com/CapeCanaveral/Lab/1000/eFOCUS.html This would be a great observing session for any astronomy club. Good Stargazing, Richard Bell http://www.geocities.com/CapeCanaveral/Lab/1000/stargazer.html Hа сегодня все, пока! =SANA=

Дата: 24 июля 1998 (1998-07-24) От: Alexander Bondugin Тема: Galileo Update - July 21, 1998 Привет всем! Вот, свалилось из Internet... MEDIA RELATIONS OFFICE JET PROPULSION LABORATORY CALIFORNIA INSTITUTE OF TECHNOLOGY NATIONAL AERONAUTICS AND SPACE ADMINISTRATION PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011 http://www.jpl.nasa.gov GALILEO EUROPA MISSION STATUS July 21, 1998 The Galileo spacecraft experienced an anomaly during its latest flyby of Jupiter's moon Europa. Neither the spacecraft nor its instruments are in immediate danger. During this encounter, a problem was detected by one of the spacecraft's two command and data subsystems, which receive commands from Earth and send back telemetry, or data from the spacecraft. Because of this, a built-in, fault-protection routine was activated, which put the spacecraft in a "safe" mode. That means the anomalous command and data subsystem was shut down, and control was turned over to the identical, second command and data subsystem. The second subsystem also detected a problem, but it is programmed to remain active as long as the first subsystem is not functioning normally. At 11:14 a.m. Pacific time on Monday, July 20, the problem was reported to ground controllers, and telemetry was initially lost. By 11:35 p.m. Pacific time, engineering telemetry from the spacecraft had been restored and communications are continuing. Engineers have activated a recovery process designed to tell them why the problem occurred; it is expected to restore full functioning to both command and data subsystems. Because of the anomaly, nearly all the data from yesterday's Europa flyby were lost and no science data will be gathered until the anomaly is corrected. Galileo successfully completed its two-year primary mission in December 1997, and is currently in the midst of its two-year extended mission. This current flyby was the fifth of the extended mission. Three more Europa flybys are scheduled, with the next one on Sept. 26. A wealth of data and pictures of Europa have already been gathered during flybys of both the primary and extended missions. The Galileo Europa Mission is managed by JPL for NASA's Office of Space Science, Washington, D.C. # # # # # Hа сегодня все, пока! =SANA=

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