在恩塞拉多斯上观察到羽毛活动和潮压力之间的相关性
M M Hedman1, C M Gosmeyer, P D Nicholson
1Center for Radiophysics and Space Research, Cornell University, Ithaca, New York 14853, USA. mmhedman@astro.cornell.edu
Nature
|August 2, 2013
概括
土星的卫星恩塞拉多在离土星最远时会排出更多的冰和水蒸气,这表明潮力量扩大了它的裂. 这种地质活动与轨道位置相关,影响了羽毛的亮度.
科学领域:
- 行星科学 行星科学
- 地质物理学 地质物理学
- 天体生物学 天体生物学
背景情况:
- 土星的一个卫星恩塞拉多斯 (Enceladus) 呈现出从它的南极喷发出水蒸气和冰颗粒的热泉.
- 假设这种地质活动受到土星的潮压力的影响,这是由于恩塞拉多斯的离心轨道.
研究的目的:
- 为了研究恩塞拉多的轨道位置与其羽毛活动之间的关系.
- 探索潮应力在控制热泉的热量和物质流量的作用.
主要方法:
- 对安塞拉多星的水平整合亮度的分析.
- 羽毛亮度变化的相关性与恩塞拉多的轨道位置 (中心和中心).
主要成果:
- 羽毛的亮度是显著更高,当恩塞拉多是在apocentre (最远的土星) 与危险中心 (最接近) 相比.
- 在中心增加的羽毛活动与预测在紧张状态下更大的裂的地球物理模型保持一致.
结论:
- 由轨道异常度调节的潮应力,可能在驱动恩塞拉多星的羽毛活动中起着至关重要的作用.
- 这些发现支持了这样一个假设:不同的潮力量控制了裂的打开和关闭,影响了从恩塞拉多的地下物质的驱逐.
相关概念视频
States of Water
46.6K
Water exists in any one of the three classical states: solid (ice), liquid (water), and gas (steam or water vapor). The state of water depends on i) the intermolecular forces that draw molecules together and ii) the kinetic energy that leads to movements that pull them apart.
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
46.6K
Tidal Forces
2.9K
The origin of Earth's ocean tides has been a subject of continuous investigation for over 2000 years. However, the work of Newton is considered to be the beginning of the proper understanding of the phenomenon. Ocean tides are the result of gravitational tidal forces. These same tidal forces are present in any astronomical body; they are responsible for the internal heat that creates the volcanic activity on Io, one of Jupiter's moons, and the breakup of stars that get too close to...
2.9K
Relation between Poisson's ratio, Modulus of Elasticity and Modulus of Rigidity
827
Deformation occurs in axial and transverse directions when an axial load is applied to a slender bar. This deformation impacts the cubic element within the bar, transforming it into either a rectangular parallelepiped or a rhombus, contingent on its orientation. This transformation process induces shearing strain. Axial loading elicits both shearing and normal strains. Applying an axial load instigates equal normal and shearing stresses on elements oriented at a 45° angle to the load axis.
827
Stress Concentrations
837
Stress concentration is when stress intensifies near discontinuities such as holes or abrupt cross-sectional changes in a structural member. This localized stress can often surpass the average stress within the member. The stress distribution in flat bars, either with a circular hole or varying widths connected by fillets, can be determined experimentally using a photoelastic method. The results are based on ratios of geometric parameters like the ratio of the hole's radius to the smaller...
837
Principal Stresses
1.1K
The graphical depiction of normal and shearing stress equations is represented by a circle, demonstrating the interplay between these stresses under different angular conditions. The center of this circle C, located on the vertical axis, represents the average normal stress, while its radius shows the range of stress variations. At points A and B, where the circle intersects the horizontal axis, the maximum and minimum normal stresses are observed, occurring without shearing stress. These...
1.1K
Pressure Variation in a Fluid at Rest
1.1K
In a fluid at rest, the pressure at any point beneath the fluid surface depends solely on the depth, not on the container's shape or size. This principle, known as hydrostatic pressure, arises because, in stationary fluids, there is no acceleration, meaning the forces within the fluid balance out. Only vertical forces, caused by the weight of the fluid above, contribute to pressure changes with depth.
When measuring pressure at two different levels within the fluid, the difference in...
When measuring pressure at two different levels within the fluid, the difference in...
1.1K


