カッシーニはエンケラドスの活発な南極を観測した
C C Porco1, P Helfenstein, P C Thomas
1Cassini Imaging Central Laboratory for Operations, Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301, USA. carolyn@ciclops.org
まとめ
カッシーニはエンケラドスの南極で地質学的に活発な地域を発見した. この地域には,若い地形,高温,土星のE環を供給する氷のジェットが特徴で,おそらく地下液体の水から来ています.
科学分野:
- 惑星科学は惑星科学である.
- 天体生物学 アストロバイオロジー
- 地質学 地質学 地質学
背景:
- 土星の6番目に大きな月であるエンケラドスは,独特の地質学的な活動を示しています.
- 以前の観測は地表の活動を示唆したが,詳細なマッピングは限られていた.
研究 の 目的:
- エンケラドスの南極にある地質学的に活発な地域を特定し,特徴づけること.
- 土星のE環を供給する氷の粒子ジェットの源を調査する.
主な方法:
- カッシーニ画像科学サブシステム (ISS) の高解像度画像の分析.
- 活性領域内のアルベド,色,温度,表面特性の検査.
主要な成果:
- 約55度南緯度に位置し,山脊と谷に囲まれた独特の州の識別.
- 異なるアルベド/色,高温,若い地質学的特徴を持つ地形の特徴.
- 狭いテクトニック・リフトの観測で,粗粒の氷と測定された最高温を観測した.
- 土星のE環を供給する氷のジェットが,地下の液体の水貯蔵所からの水蒸気によって駆動され,この州から発生していることを確認しました.
結論:
- エンケラドスの南極地域は地質学的に活発な地域であり,最近地表に浮上し,地下に液体の水が存在している証拠があります.
- 観測された特徴と現象は,エンケラドスの地下海洋の仮説を裏付けている.
- 月の形状は,過去の激しい加熱イベントを示唆し,おそらく軌道共鳴に関連している.
関連する概念動画
Hess's Law
There are two ways to determine the amount of heat involved in a chemical change: measure it experimentally, or calculate it from other experimentally determined enthalpy changes. Some reactions are difficult, if not impossible, to investigate and make accurate measurements for experimentally. And even when a reaction is not hard to perform or measure, it is convenient to be able to determine the heat involved in a reaction without having to perform an experiment.
Kepler's First Law of Planetary Motion
In the early 17th century, German astronomer and mathematician Johannes Kepler postulated three laws for the motion of planets in the solar system. He formulated his first two laws based on the observations of his forebears, Nikolaus Copernicus and Tycho Brahe.
Polish astronomer Nikolaus Copernicus put forth a theory that stated a heliocentric model for the solar system. According to this heliocentric theory, all the planets, including Earth, orbit the Sun in circular orbits.
On the other hand,...
Polish astronomer Nikolaus Copernicus put forth a theory that stated a heliocentric model for the solar system. According to this heliocentric theory, all the planets, including Earth, orbit the Sun in circular orbits.
On the other hand,...
Kepler's Second Law of Planetary Motion
In the early 17th century, German astronomer and mathematician Johannes Kepler postulated three laws for the motion of planets in the solar system. His first law states that all planets orbit the Sun in an elliptical orbit, with the Sun at one of the ellipse's foci. Therefore, the distance of a planet from the Sun varies throughout its revolution around the Sun.
While in an elliptical orbit, the total energy of the planet is conserved. Therefore, the planet slows down when it is at apogee and...
While in an elliptical orbit, the total energy of the planet is conserved. Therefore, the planet slows down when it is at apogee and...
Kepler's Third Law of Planetary Motion
In the early 17th century, German astronomer and mathematician Johannes Kepler postulated three laws for the motion of planets in the solar system. In 1909, he formulated his first two laws based on the observations of his forebears, Nikolaus Copernicus and Tycho Brahe. However, in 1918, he published his third law of planetary motion, which gives a precise mathematical relationship between a planet's average distance from the Sun and the amount of time it takes to revolve around the Sun. It...
Magnetic Declination
Magnetic declination is the angle between true north, which aligns with the Earth's rotational axis, and magnetic north, which follows the direction of the Earth's magnetic field. This discrepancy exists because the magnetic poles do not coincide with the geographic poles. The value of magnetic declination depends on the observer's location on Earth and is subject to changes over time due to the dynamic nature of the Earth's magnetic field.The declination is called eastern when magnetic north...
Polar Equations of Conics
A conic section can be defined in polar coordinates as the set of all points whose distance from a fixed point, known as the focus, bears a constant ratio to their distance from a fixed line, known as the directrix. This constant ratio is called the eccentricity. This definition unifies all types of conic sections—ellipses, parabolas, and hyperbolas—under a single framework. When the focus is positioned at the origin of the polar coordinate system, a single polar equation can describe any conic...


