関連する実験動画
Updated: May 21, 2025

08:14
Atom Probe Tomography Analysis of Exsolved Mineral Phases
Published on: October 25, 2019
7.1K
月面マントルの熱アシンメトリは,毎月の潮反応から推測される
R S Park1, A Berne2, A S Konopliv3
1Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA. Ryan.S.Park@jpl.nasa.gov.
Nature
|May 14, 2025
まとめ
月
科学分野:
- 月の地質学
- 惑星科学
- 固体地球地質学
背景:
- 地球からの潮力によって 月の重力場が変化します
- これらの変化は月の内部構造に敏感です
- 過去のモデルでは 月の内部が対称だと考えられていました
研究 の 目的:
- 宇宙船のデータを用いて 時間の変動による月の重力場を 復元する
- 3度重力潮のラブ数 (k3) を決定する.
- 月の内部構造を調査する
主な方法:
- NASAのGRAIL宇宙船のデータを活用した
- 月の重力場が 変化しているのを発見した
- 3度重力潮のラブ数 (k3) を計算した.
主要な成果:
- 推定 k3 = 0.0163 ± 0.0007 とする.
- この値は対称な月で予想される値より 72%高い.
- 大きなk3は,マントルの弾性シーアモジュールの有意な変動を示唆する.
結論:
- 月の内部は球体対称ではありません
- 月の深層マントルの側面の異質性が確認されました
- 月面マントルの恒常的な熱異常は 月面の地質学と地震性に影響する
関連する概念動画
Tidal Forces
2.5K
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...
2.5K
Simple Harmonic Motion and Uniform Circular Motion
4.1K
While simple harmonic motion and uniform circular motion may be two separate concepts, they correlate and interlink with each other. Simple harmonic motion is an oscillatory motion in a system where the net force can be described by Hooke's law, while uniform circular motion is the motion of an object in a circular path at constant speed.
There is an easy way to produce simple harmonic motion by using uniform circular motion. For instance, consider a ball attached to a uniformly rotating...
There is an easy way to produce simple harmonic motion by using uniform circular motion. For instance, consider a ball attached to a uniformly rotating...
4.1K
Gravity between Spherical Bodies
8.2K
Newton's law of gravitation describes the gravitational force between any two point masses. However, for extended spherical objects like the Earth, the Moon, and other planets, the law holds with an assumption that masses of spherical objects are concentrated at their respective centers.
This assumption can be proved easily by showing that the expression for gravitational potential energy between a hollow sphere of mass (M) and a point mass (m) is the same as it would be for a pair of extended...
This assumption can be proved easily by showing that the expression for gravitational potential energy between a hollow sphere of mass (M) and a point mass (m) is the same as it would be for a pair of extended...
8.2K
Gravitation
6.1K
In the years before Newton, a general belief prevailed that different laws governed objects in the sky than objects on Earth. When Kepler wrote down the three laws of planetary motion, explaining in detail the geometrical properties of the planetary orbits around the Sun, there was no immediate idea to discern their connection with more fundamental laws. It was Isaac Newton who, in 1665–66, figured out the connection between planetary motion, the motion of the moon around the Earth, and...
6.1K
Apparent Weight and the Earth's Rotation
3.5K
Since all objects on the Earth's surface move through a circle every 24 hours, there must be a net centripetal force on each object, directed towards the center of that circle. The points of the north and south poles are the only exception to this rule.
For an object on the Earth's equator, the net centripetal force that accounts for its rotation is the Earth's pull towards its center, or the weight minus the normal force that prevents it from piercing into the Earth's surface....
For an object on the Earth's equator, the net centripetal force that accounts for its rotation is the Earth's pull towards its center, or the weight minus the normal force that prevents it from piercing into the Earth's surface....
3.5K
Atomic Nuclei: Larmor Precession Frequency
1.1K
The earth's gravitational field produces a 'twisting force' perpendicular to the angular momentum of a spinning mass (such as a spinning top) that causes the mass to 'wobble' around the gravitational field axis in a phenomenon called precession. Similarly, the magnetic moment (μ) of a spinning nucleus precesses due to an external magnetic field directed along the z-axis. The precession of the magnetic moment vector about the magnetic field is called Larmor precession,...
1.1K

