月面の南極の内部に露出氷が不足しているシャクルトンクレーター
Junichi Haruyama1, Makiko Ohtake, Tsuneo Matsunaga
1Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Kanagawa 229-85105, Japan.
まとめ
シャクルトンクレーターは水氷を保持しているかもしれないが,画像は床に純粋な氷の堆積物を明らかにしていない. 氷が土壌と混ざっているか,欠けているかを確認するためにさらなる分析が必要である.
科学分野:
- 月科学は月科学である.
- 惑星地質学 惑星地質学
- 天体生物学 アストロバイオロジー
背景:
- 月の南極にあるシャクルトンクレーター (Shackleton Crater) は,永久に影に包まれています.
- 以前の研究では,クレーター内に水の氷の積みが存在することを推測しました.
研究 の 目的:
- シャクルトンクレーターの内部をイメージする.
- 水氷の積層の存在と形態を評価する.
主な方法:
- セレノロジック・アンド・エンジニアリング・エクスプローラー (SELENE) 宇宙船の地形カメラ (TC) を利用しました.
- TCステレオデータからクレーターの形状モデルを開発しました.
- クレーター床のアルベドと推定温度を分析した.
主要な成果:
- 暗く照らされたクレーター内部の画像が成功しました.
- 推定クレーターの床温度は90ケルビン以下で,水氷に適しています.
- TCの空間解像度のアルベドデータは,露出した純水氷の堆積物が存在しないことを示唆しています.
結論:
- 条件は氷を作るのに十分な寒さですが,現在の解像度では純粋な水氷の直接的な証拠は見つかりませんでした.
- 水の氷は,レゴリットの中に散布されているか,クレーターの床から欠けています.
関連する概念動画
Graphs of Polar Equations
The polar coordinate system represents points using a distance from a central point (the pole) and an angle from a reference direction (the polar axis). Unlike rectangular coordinates, polar coordinates are ideal for graphing curves with radial symmetry or periodic behavior.Some general forms of graphs in polar coordinates include the following:Equation of a Circle (Centered at the Pole):A graph where the radius remains constant for all angles traces a circle centered at the pole:Equation of a...
Frost Action on Concrete
Concrete structures in cold climates, such as those along roadsides, can retain moisture. This moisture makes them susceptible to frost-related damage when temperatures fall below freezing. Adding moisture worsens the damage during temperature fluctuations, leading to repeated freezing and thawing. De-icing salts, spread over these structures to melt ice, add to the freeze-thaw cycle, and draw even more moisture into the concrete.
This freeze-thaw cycle primarily causes surface scaling, where...
This freeze-thaw cycle primarily causes surface scaling, where...
Potential Due to a Polarized Object
A neutral atom consists of a positively charged nucleus surrounded by a negatively charged electron cloud. When placed in an external electric field, the external electric force pulls the electrons and nucleus apart, opposite to the intrinsic attraction between the nucleus and the electrons. The opposing forces balance each other with a slight shift between the center of masses of the nucleus and the electron cloud, resulting in a polarized atom. On the other hand, a few molecules, like water,...
Masonry in Cold and Hot Weather Conditions
In cold weather, masonry construction requires specific precautions to ensure mortar does not freeze before curing, as this can significantly weaken its strength and watertightness. Mortar temperature should be maintained between 60°F and 80°F to support proper hydration and curing. Below 40°F, mortar water must be heated, but should not exceed 120°F as high temperatures can reduce mortar's compressive and bond strength.
Other key practices include keeping masonry units and sand dry and...
Other key practices include keeping masonry units and sand dry and...
Global Climate Change
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
Phase Transitions: Melting and Freezing
Heating a crystalline solid increases the average energy of its atoms, molecules, or ions, and the solid gets hotter. At some point, the added energy becomes large enough to partially overcome the forces holding the molecules or ions of the solid in their fixed positions, and the solid begins the process of transitioning to the liquid state or melting. At this point, the temperature of the solid stops rising, despite the continual input of heat, and it remains constant until all of the solid is...


