火星的大气历史来源于上层大气测量38Ar/36Ar
B M Jakosky1, M Slipski2, M Benna3
1University of Colorado, Boulder, CO, USA. bruce.jakosky@lasp.colorado.edu.
概括
火星已经失去了大气中66%的气. 这种显著的气体流失解释了地球
科学领域:
- 星球科学
- 大气科学
- 天体生物学
背景情况:
- 了解火星的大气历史对于评估其地质演变和过去的可居住性至关重要.
- 从一个可能温暖,潮湿的早期火星到目前的寒冷,干燥状态的过渡与大气损失有关.
研究的目的:
- 测量大气气体随着时间的推移而流失的数量.
- 调查火星大气逃逸的机制.
主要方法:
- 利用来自火星大气和挥发性进化 (MAVEN) 飞船的数据.
- 分析了上层大气结构, 特别是38Ar/36Ar同位素比.
- 在同位点和外基高度之间的同位素结构.
主要成果:
- 由于较轻的同位素的偏好损失,确定了同位素的显著分离.
- 估计火星大气中66%的气已经消失在太空中.
- 建立了大气逃逸与火星气候演变之间的直接联系.
结论:
- 火星大气层的很大一部分已经进入太空.
- 大气损失是火星气候转变的一个关键因素.
- 这项研究提供了关于火星过去可居住性的重要见解.
相关概念视频
Definition and Measurement of Pressure: Atmospheric Pressure, Barometer, and Manometer
34.1K
Gas pressure is caused by force exerted by gas molecules colliding with the surfaces of objects. Although the force of each collision is very small, any surface of an appreciable area experiences a large number of collisions in a short time, which can result in high pressure.
34.1K
Noble Gases
16.5K
The elements in group 18 are noble gases (helium, neon, argon, krypton, xenon, and radon). They earned the name “noble” because they were assumed to be nonreactive since they have filled valence shells. In 1962, Dr. Neil Bartlett at the University of British Columbia proved this assumption to be false.
16.5K
Radioactive Decay and Radiometric Dating
34.6K
Radioactivity is a spontaneous disintegration of an unstable nuclide and is a random process, as all the nuclei in the sample do not decay simultaneously. The number of disintegrations per unit time is called the activity (A), which is directly proportional to the number of nuclei in the sample. The decay constant (λ) is an average probability of decay per nucleus in unit time.
34.6K
Variation of Atmospheric Pressure
3.6K
Change in atmospheric pressure with height is particularly interesting. The decrease in atmospheric pressure with increasing altitude is due to the decreasing gravitational force per unit area as we move away from the surface of the earth.
Assuming the air temperature is constant at a given altitude and that the ideal gas law of thermodynamics describes the atmosphere to a good approximation, one can find the variation of atmospheric pressure with height.
Let p(y) be the atmospheric pressure at...
Assuming the air temperature is constant at a given altitude and that the ideal gas law of thermodynamics describes the atmosphere to a good approximation, one can find the variation of atmospheric pressure with height.
Let p(y) be the atmospheric pressure at...
3.6K
Attenuated Total Reflectance (ATR) Infrared Spectroscopy: Overview
1.5K
Attenuated total reflectance (ATR) infrared spectroscopy is a powerful analytical technique used to study the composition of materials. It is widely employed in chemistry, materials science, forensic science, and other fields where sample characterization is required. ATR has several advantages over traditional transmission IR spectroscopy, including the requirement of little to no sample preparation and the ability to analyze a wide range of samples.
The ATR process begins by directing a beam...
The ATR process begins by directing a beam...
1.5K
Impact: Problem Solving
615
In an experiment conducted during a Mars mission, a rover propels a projectile with an initial velocity, and the projectile rebounds after colliding with the Martian surface. To ascertain the maximum height attained by the projectile after this collision, the known restitution coefficient and acceleration due to gravity are employed.
By designating the launch point as the origin and utilizing kinematic equations, the vertical component of the projectile's velocity at the point of impact is...
By designating the launch point as the origin and utilizing kinematic equations, the vertical component of the projectile's velocity at the point of impact is...
615


