太陽風による噴霧による火星の大気の消失
1Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena 91125, USA.
まとめ
火星は,太陽風の侵食によって35億年以上にわたって約3バーの二酸化炭素 (CO2) を失っている. この改訂された推定値は,地球の大気進化の理解に大きな影響を与えます.
科学分野:
- 惑星科学 惑星科学
- 大気科学 大気科学
- 天体生物学 アストロバイオロジー
背景:
- 火星には強い固有の磁場がないため,その大気は太陽風による侵食に脆弱である.
- 初期の太陽系条件は,火星の大気損失を悪化させた可能性が高い.
研究 の 目的:
- 過去35億年にわたって火星の大気から失われた二酸化炭素 (CO2) の総量を計算します.
- 火星からの水の損失の推定を精査するためです.
主な方法:
- より完全な大気損失モデルの開発.
- 新しいモデルに基づくCO2スプッタリング損失の計算.
主要な成果:
- 約3本の二酸化炭素が35億年にわたって噴出され,これは以前の推定値 (約1.3億年) よりも大幅に増加した. 0.14バー) である.
- このモデルは,より大きな水の損失 (約. 以前の研究と比較して (約80メートル) でした. 50メートル) です.
結論:
- 改訂されたCO2損失推定値 (約. 3バー) は,初期の火星の大気組成と進化の理解に大きな影響を与えます.
- これまでのCO2損失の推定値は,地球の大気の歴史を説明するのに不十分でした.
関連する概念動画
The Sulfur Cycle
Sulfur, an important element in the chemical makeup of proteins, is recycled through the atmosphere and aquatic and terrestrial environments. Found in the atmosphere as sulfur dioxide (SO2), sulfur is released by decaying organisms, weathered rocks, geothermal vents, volcanos, and burning fossil fuels. It is deposited into the ecosystem, cycled through the biotic community, and either released back into the atmosphere as gas or deposited in marine sediment for long-term storage and eventual...
Acceleration due to Gravity on Other Planets
The gravitational acceleration of an object near the Earth's surface is called the acceleration due to gravity. It can be measured by conducting simple experiments on Earth. However, such an experiment is impossible to conduct on the surface of other planets.
Astronomical observations are thus used to measure the acceleration due to gravity on other planets. This can be determined by observing the effect of a planet's gravity on objects close to it. The crucial factor that helps in this...
Astronomical observations are thus used to measure the acceleration due to gravity on other planets. This can be determined by observing the effect of a planet's gravity on objects close to it. The crucial factor that helps in this...
Momentum And Radiation Pressure
An object absorbing an electromagnetic wave would experience a force in the direction of propagation of the wave. This force occurs because electromagnetic waves contain and transport momentum. The force accounts for the wave's radiation pressure exerted on the object. Maxwell's prediction was confirmed in 1903 by Nichols and Hull by precisely measuring radiation pressures with a torsion balance. The measuring instrument had mirrors suspended from a fiber kept inside a glass container. Nichols...
Escape Velocities of Gases
To escape the Earth's gravity, an object near the top of the atmosphere at an altitude of 100 km must travel away from Earth at 11.1 km/s. This speed is called the escape velocity. The temperature at which gas molecules attain the rms speed, which is equal to the escape velocity, can be estimated by using the equation for the average kinetic energy of the gas molecules. According to the kinetic theory of gas, the average kinetic energy of the gas molecules is proportional to its temperature.
Radiation Pressure: Problem Solving
The radiation pressure applied by an electromagnetic wave on a perfectly absorbing surface equals the energy density of the wave. The wave's momentum also gets transferred to the surface when an electromagnetic wave is entirely absorbed by it. The rate at which momentum is transmitted to an absorbing surface perpendicular to the propagation direction equals the force on the surface.
The average value of the rate of momentum transfer divided by the absorbing area represents the average force per...
The average value of the rate of momentum transfer divided by the absorbing area represents the average force per...
Torque Free Motion
The torque-free motion refers to the movement of a rigid body in space when no external torques are acting upon it. This type of motion can be observed in environments where there are no external forces or frictions, like in outer space. For example, a rotation of Mars in space is a torque-free motion. Mars is an axisymmetric object, meaning it has an axis of symmetry along which it rotates, designated as the z-axis. The rotating frame of reference is defined such that the center of mass of...


