نتایج جستجو برای: earth atmosphere

تعداد نتایج: 143613  

Journal: :Science 2009
Huiming Bao Ian J Fairchild Peter M Wynn Christoph Spötl

The oxygen isotope composition of terrestrial sulfate is affected measurably by many Earth-surface processes. During the Neoproterozoic, severe "snowball" glaciations would have had an extreme impact on the biosphere and the atmosphere. Here, we report that sulfate extracted from carbonate lenses within a Neoproterozoic glacial diamictite suite from Svalbard, with an age of approximately 635 mi...

2008
E. Churazov S. Sazonov R. Sunyaev M. Revnivtsev

We present calculations of the reflection of the cosmic X-ray background (CXB) by the Earth’s atmosphere in the 1–1000 keV energy range. The calculations include Compton scattering and X-ray fluorescent emission and are based on a realistic chemical composition of the atmosphere. Such calculations are relevant for CXB studies using the Earth as an obscuring screen (as was recently done by INTEG...

Journal: :Astrobiology 2013
David J Smith

Microbial taxa from every major biological lineage have been detected in Earth's upper atmosphere. The goal of this review is to communicate (1) relevant astrobiology questions that can be addressed with upper atmosphere microbiology studies and (2) available sampling methods for collecting microbes at extreme altitudes. Precipitation, mountain stations, airplanes, balloons, rockets, and satell...

Journal: :Physical review letters 2011
K D de Vries A M van den Berg O Scholten K Werner

Very energetic cosmic rays entering the atmosphere of Earth will create a plasma cloud moving with almost the speed of light. The magnetic field of Earth induces an electric current in this cloud which is responsible for the emission of coherent electromagnetic radiation. We propose to search for a new effect: Because of the index of refraction of air, this radiation is collimated in a Cherenko...

2003
K. Shiomi A. Yamazaki I. Yoshikawa Y. Takizawa M. Nakamura

1. Introduction Planet-B, which will arrive at the Mars in early 2004, is the first Mars explorer of Japan. Extreme Ultraviolet scanner (XUV) onboard Planet-B was a newly developed telescope for measuring an amount of helium gas and ions, which emit resonantly scattered light, on Martian atmosphere and ionosphere. XUV observed moonlight at a distance of 80 Earth radii (R E) when Planet-B was in...

Journal: :Cold Spring Harbor perspectives in biology 2010
Kevin Zahnle Laura Schaefer Bruce Fegley

Earth is the one known example of an inhabited planet and to current knowledge the likeliest site of the one known origin of life. Here we discuss the origin of Earth's atmosphere and ocean and some of the environmental conditions of the early Earth as they may relate to the origin of life. A key punctuating event in the narrative is the Moon-forming impact, partly because it made Earth for a s...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2013
Xiaobin Cao Huiming Bao

A large perturbation in atmospheric CO2 and O2 or bioproductivity will result in a drastic pulse of (17)O change in atmospheric O2, as seen in the Marinoan Oxygen-17 Depletion (MOSD) event in the immediate aftermath of a global deglaciation 635 Mya. The exact nature of the perturbation, however, is debated. Here we constructed a coupled, four-box, and quick-response biosphere-atmosphere model t...

2005
S. Balestra

We discuss the properties of cosmic ray nuclearites, from the point of view of their search with large nuclear track detector arrays exposed at different altitudes, in particular with the SLIM experiment at the Chacaltaya high altitude lab (5290 m a.s.l.). We present calculations concerning their propagation in the Earth atmosphere and discuss their possible detection with CR39 and Makrofol nuc...

2006
ARNAUD CZAJA JOHN MARSHALL

Observations of the poleward heat transport of the earth (H ) suggest that the atmosphere is the primary transporting agent poleward of 30°, that oceanic (HO) and atmospheric (HA) contributions are comparable in the tropical belt, and that ocean transport dominates in the deep Tropics. To study the partition we express the ratio HA/HO as

2014
Joohyung Lee Keunwoo Lee Yoon-Soo Jang Heesuk Jang Seongheum Han Sang-Hyun Lee Kyung-In Kang Chul-Woo Lim Young-Jin Kim Seung-Woo Kim

We report a test operation of an Er-doped fibre femtosecond laser which was conducted for the first time in outer space. The fibre-based ultrashort pulse laser payload was designed to meet space-use requirements, undergone through ground qualification tests and finally launched into a low-earth orbit early in 2013. Test results obtained during a one-year mission lifetime confirmed stable mode-l...

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