火星からの中性子の地球分布: 火星オデッセイの結果
W C Feldman1, W V Boynton, R L Tokar
1Los Alamos National Laboratory, Los Alamos, NM 87545, USA. wfeldman@lanl.gov
Science (New York, N.Y.)
|June 1, 2002
まとめ
グローバルニュートロンフルスマッピングは,火星の水氷と二酸化炭素の堆積物を明らかにしています. 緯度60度以南の水素豊富な地域には,埋もれた水氷が含まれており,極地には二酸化炭素が多く存在します. 地下水の埋蔵は,より低い緯度でも示されています.
科学分野:
- 惑星科学は惑星科学である.
- アストロジオロジー アストロジオロジー
- 地質物理学 地質物理学とは地質物理学です.
背景:
- 水素と二酸化炭素の分布を理解することは,火星の過去と現在の気候を特徴づける上で極めて重要です.
- Mars Odyssey Neutron Spectrometer (MONS) は,火星の地下にあるこれらの揮発性元素をマッピングするためのユニークなデータセットを提供します.
研究 の 目的:
- 火星の熱,熱帯,高速中性子流の地球分布をマッピングする.
- 水素 (H2Oとして) と二酸化炭素 (CO2) の地表近くの環境における空間的分布を推論する.
主な方法:
- マース・オデッセイ・ニュートロンスペクトロメーター (MONS) のデータを活用した.
- 分析された中性子流量測定は,水素とCO2含有量に敏感です.
- 南部の晩夏/北部の冬の分布をマッピングした.
主要な成果:
- +/−60°緯度の極東に水素が豊富な地形が特定され,埋もれた水氷の兆候である.
- 厚い二酸化炭素層が中央の北極帽と残った南極帽を覆っていることが観察されました.
- 低緯度から中緯度まで,結合水 (H2O) および/またはヒドロキシル (OH) の地下堆積物の証拠が検出されました.
結論:
- この研究は,火星の主要な揮発性分布のグローバルマップを提供します.
- 発見は,高緯度で重要な水氷貯蔵庫と,極地で二酸化炭素の氷があることを示唆している.
- 低緯度における結合水/OHの証拠は,火星の水分化過程のさらなる調査を保証する.
関連する概念動画
00:54Distribution and Dispersion
Ecology is the study of how organisms interact with their environment and with one another. An important aspect of ecology is understanding where species are found and how individuals are distributed within those areas. The geographic range of a species refers to the total area where its members are located, while dispersion describes the pattern of spacing of individuals within that range.Geographic Range and Dispersion PatternsWithin a species’ geographic range, individuals may be distributed...
01:11Energy of a Satellite in a Circular Orbit
Thousands of artificial satellites orbit the Earth every day at various distances from the Earth. Satellites that orbit the Earth below an altitude of 1,600 km are considered to be orbiting in low-Earth orbit (LEO). Research satellites and Earth observation satellites are usually placed in LEO, and mostly orbit the Earth in elliptical orbits. Navigation satellites are placed in medium-Earth orbit (MEO), ranging from 2,000 km to 36,000 km from the surface of the Earth. Meanwhile, communication...
01:10Kepler's First Law of Planetary Motion
In the early 17th century, German astronomer and mathematician Johannes Kepler postulated three laws for the motion of planets in the solar system. He formulated his first two laws based on the observations of his forebears, Nikolaus Copernicus and Tycho Brahe.
Polish astronomer Nikolaus Copernicus put forth a theory that stated a heliocentric model for the solar system. According to this heliocentric theory, all the planets, including Earth, orbit the Sun in circular orbits.
On the other hand,...
Polish astronomer Nikolaus Copernicus put forth a theory that stated a heliocentric model for the solar system. According to this heliocentric theory, all the planets, including Earth, orbit the Sun in circular orbits.
On the other hand,...
01:29Kepler's Second Law of Planetary Motion
In the early 17th century, German astronomer and mathematician Johannes Kepler postulated three laws for the motion of planets in the solar system. His first law states that all planets orbit the Sun in an elliptical orbit, with the Sun at one of the ellipse's foci. Therefore, the distance of a planet from the Sun varies throughout its revolution around the Sun.
While in an elliptical orbit, the total energy of the planet is conserved. Therefore, the planet slows down when it is at apogee and...
While in an elliptical orbit, the total energy of the planet is conserved. Therefore, the planet slows down when it is at apogee and...
01:18Kepler's Third Law of Planetary Motion
In the early 17th century, German astronomer and mathematician Johannes Kepler postulated three laws for the motion of planets in the solar system. In 1909, he formulated his first two laws based on the observations of his forebears, Nikolaus Copernicus and Tycho Brahe. However, in 1918, he published his third law of planetary motion, which gives a precise mathematical relationship between a planet's average distance from the Sun and the amount of time it takes to revolve around the Sun. It...
01:18Fermi Level
The Fermi-Dirac function is represented by an S-shaped curve indicating the probability of an energy state being occupied by an electron at a given temperature. The Fermi level is the energy level at which there is a fifty percent chance of finding an electron, and it is positioned between the lower-energy valence band and the higher-energy conduction band.
At absolute zero temperature, electrons fill all energy states up to the Fermi level, leaving upper states empty. As the temperature rises,...
At absolute zero temperature, electrons fill all energy states up to the Fermi level, leaving upper states empty. As the temperature rises,...