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31.
Extraterrestrial organic matter may have been chemically altered into forms more ameanable for prebiotic chemistry in the wake of a meteor after ablation. We measured the rate of cooling of the plasma in the meteor wake from the intensity decay just behind a meteoroid by freezing its motion in high frame-rate 1000 frames/s video images, with an intensified camera that has a short phosphor decay time. Though the resulting cooling rate was found to be lower than theoretically predicted, our calculations indicated that there would have been insufficient collisions to break apart large organic compounds before most reactive radicals and electrons were lost from the air plasma. Organic molecules delivered from space to the early Earth via meteors might therefore have survived in a chemically altered form. In addition, we discovered that relatively small meteoroids generated far-ultraviolet emission that is absorbed in the immediate environment of the meteoroid, which may chemically alter the atmosphere over a much larger region than previously recognized.  相似文献   
32.
Culture is an organized group of learned responses of a particular society, or the total round of human activities, not due to heredity, shared by members of a group. This means that culture is a dynamic process and it is in tight relationship to the civilization as a tool to master their all day's tasks. Space science is a result of the shift from the mass production civilization to the knowledge civilization. The science had opened new ways of thinking into a new environment, space. The ability to develop thinking to new living areas is already a learned response to the environment and therefore an act of culture.

The next changes in culture are a result of the different view, mankind has from earth looking back out of the spacecraft window. We see now with other eyes the small and vulnerable living area of mankind. We see no political limits partitioning the surface. We understand time zones as systems properties of the regions. This has up to now influenced big groups of the societies. As this view has to be shared by all members of the societies in the same mode, space education has to organize this effect.  相似文献   

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34.
Since 1991 the United Nations Office for Outer Space Affairs has been conducting a series of workshops on basic space science under its United Nations Programme on Space Applications. Up to 2004 the workshops focussed on capacity building efforts in basic space science, in particular for the benefit of developing countries. From 2005 onwards the workshops and their related activities contributed to the celebration of the International Heliophysical Year 2007. Together these activities and workshops constitute the United Nations Basic Space Science Initiative of the United Nations Office for Outer Space Affairs. This paper reflects on the achievements and outcomes of the Initiative and informs about considerations for its future evolution.  相似文献   
35.
For more than a decade Kayser-Threde, a medium-sized enterprise of the German space industry, has been involved in astrobiology research in partnership with a variety of scientific institutes from all over Europe. Previous projects include exobiology research platforms in low Earth orbit on retrievable carriers and onboard the Space Station. More recently, exobiology payloads for in situ experimentation on Mars have been studied by Kayser-Threde under ESA contracts, specifically the ExoMars Pasteur Payload. These studies included work on a sample preparation and distribution systems for Martian rock/regolith samples, instrument concepts such as Raman spectroscopy and a Life Marker Chip, advanced microscope systems as well as robotic tools for astrobiology missions. The status of the funded technical studies and major results are presented. The reported industrial work was funded by ESA and the German Aerospace Center (DLR).  相似文献   
36.
We have surveyed solar wind plasma beta and field-aligned Alfvénic Mach number using Ulysses and Wind data. We show the characteristic timescale and occurrence frequency of ‘magnetically dominated’ solar wind, whose interaction with a planetary magnetosphere may produce a bow shock with multiple shock fronts. We discuss radial, latitudinal, and solar cycle effects. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
37.
AESA技术已达到了成熟的技术阶段,正被先进的雷达项目所采用。T/R模块是使之实现的关键技术,降低其成本的工作也正在进行。在未来应用方面,已经考虑了氮化镓(GaN)、微机电射频(MEMsRF)开关和瓦式T/R模块,它们将为共形和多功能AESA雷达系统铺平道路。  相似文献   
38.
The boundary conditions for a non-destructive sample acquisition system are outlined and the development of a new robotic sampling system suited for use on a cometary surface is briefly discussed. Additionally we present some new results on strength and deformation behaviour of synthetic cometary analogue material.  相似文献   
39.
The COMPTEL telescope aboard the Compton Gamma Ray Observatory has put MeV -rays into the midst of astronomy. Among recent highlights are the discovery of intense MeV emission from blazar-type active galactic nuclei, the surprising non-detection of any Seyfert galaxy at MeV energies, the first image of the Milky Way in the light of the26Al line at 1.809 MeV (possibly including a detection of the Vela supernova remnant), the discovery of 3–7 MeV emission from the Orion complex, which can be identified with nuclear interaction lines of12C and16O at 4.44 and 6.13 MeV, the detection of the44Ti line at 1.15 MeV from the supernova remnant Cas A, and the first results on the spectrum and propagation of low-energy (1–100 MeV) cosmic-ray electrons.also Leiden Observatory  相似文献   
40.
he burst alert telescope (BAT) is one of three instruments on the Swift MIDEX spacecraft to study gamma-ray bursts (GRBs). The BAT first detects the GRB and localizes the burst direction to an accuracy of 1–4 arcmin within 20 s after the start of the event. The GRB trigger initiates an autonomous spacecraft slew to point the two narrow field-of-view (FOV) instruments at the burst location within 20–70 s so to make follow-up X-ray and optical observations. The BAT is a wide-FOV, coded-aperture instrument with a CdZnTe detector plane. The detector plane is composed of 32,768 pieces of CdZnTe (4×4×2 mm), and the coded-aperture mask is composed of ∼52,000 pieces of lead (5×5×1 mm) with a 1-m separation between mask and detector plane. The BAT operates over the 15–150 keV energy range with ∼7 keV resolution, a sensitivity of ∼10−8 erg s−1 cm−2, and a 1.4 sr (half-coded) FOV. We expect to detect > 100 GRBs/year for a 2-year mission. The BAT also performs an all-sky hard X-ray survey with a sensitivity of ∼2 m Crab (systematic limit) and it serves as a hard X-ray transient monitor.  相似文献   
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