(1) セレスの水性変化の証拠としての明るい炭酸堆積物

M C De Sanctis, A Raponi, E Ammannito

Nature

|July 1, 2016

まとめ

小惑星セレスの明るい領域,特にオクタールクレーターは,炭酸ナトリウムが豊富です. これらの発見は水溶液と固体が底から結晶化したことを示し今日のセレスの潜在的地下液体を示しています

科学分野:

惑星科学
天文地質学
地化学

背景:

セレスの表面は主に暗く,特にオクタークレーターには明るい部分があります.
前回の解釈では,これらの明るい領域で水素化マグネシウム硫酸を示唆しました.
表面の平均組成にはアルベドが低い材料,マグネシウムフィロシリケート,アンモニア酸フィロシリケート,炭酸塩が含まれています.

研究の目的:

セレスのオクタークレーターの明るい領域の構成を分析する.
これらの明るい堆積物の起源と影響を調査する.

主な方法:

高い空間とスペクトルの解像度を持つ近赤外線観測
オクタークレーター内の明るい領域のスペクトル分析.

主要な成果:

Spectraは明るい領域に炭酸ナトリウムの有意な存在を示しています
これは最も濃縮された地球外炭酸塩の堆積物で 1キロ幅のスケールで発見されました
検出された他の化合物は,フィロシリケート,炭酸アンモニア,または塩化アンモニアを,暗い成分と混合したものです.

結論:

特定された化合物は内生性であり,結晶化した塩水とセレスの内部から変化した固体から形成されている可能性が高い.
暫定的な衝撃の加熱や地下塩水の持続的な温度がこれらの形成を説明できる.
この発見は,セレスに存在する地下液体の可能性を示唆している.

さらに関連する動画

11:14

Two-way Valorization of Blast Furnace Slag: Synthesis of Precipitated Calcium Carbonate and Zeolitic Heavy Metal Adsorbent

Published on: February 21, 2017

13.0K

09:31

Calcium Carbonate Formation in the Presence of Biopolymeric Additives

Published on: May 14, 2019

17.5K

関連する概念動画

01:14

The Carbon Cycle

45.4K

Carbon is the basis of all organic matter on Earth, and is recycled through the ecosystem in two primary processes: one in which carbon is exchanged among living organisms, and one in which carbon is cycled over long periods of time through fossilized organic remains, weathering of rocks, and volcanic activity. Human activities, including increased agricultural practices and the burning of fossil fuels, has greatly affected the balance of the natural carbon cycle.

45.4K

01:24

Hydration of Cement

1.3K

Hydration of cement is a chemical reaction between cement particles and water. This process occurs primarily through two mechanisms: through-solution and topochemical. In the through-solution process, anhydrous compounds dissolve into their constituents, hydrates form in the solution, and then precipitate from the supersaturated solution. The topochemical process involves solid-state reactions at the cement particle surface. The through-solution process dominates the topochemical process at the...

1.3K

01:24

Carbonation Shrinkage

541

Atmospheric CO2 penetrates the concrete's pores and, in the presence of moisture, forms carbonic acid, which then reacts with calcium hydroxide in the hydrated cement, forming calcium carbonate. This process reduces the concrete's volume and is termed carbonation shrinkage.
The concrete's permeability is slightly reduced as calcium carbonate produced during the reaction fills its pores. Furthermore, its strength is slightly enhanced as the water released during the reaction...

541

03:46

Qualitative Analysis

27.9K

For solutions containing mixtures of different cations, the identity of each cation can be determined by qualitative analysis. This technique involves a series of selective precipitations with different chemical reagents, each reaction producing a characteristic precipitate for a specific group of cations. Metal ions within a group are further separated by varying the pH, heating the mixture to redissolve a precipitate, or adding other reagents to form complex ions.
For instance, group IV...

27.9K

01:29

Sulfate Attack on Concrete

892

Sulfate attack on concrete is a deterioration process characterized by a whitish discoloration beginning at the edges and corners, accompanied by cracking and spalling. This phenomenon occurs when sulfates react with the components of hardened concrete, forming compounds like calcium sulfate and calcium sulfoaluminate which occupy more space than the substances they replace, causing the concrete to expand and disrupt.
Sulfates from sources like soil, groundwater, or industrial effluents...

892

02:56

The Fossil Record

28.3K

The fossil record documents only a small fraction of all organisms that have ever inhabited Earth. Fossilization is a rare process, and most organisms never become fossils. Moreover, the fossil record only exhibits fossils that have been discovered. Nevertheless, sedimentary rock fossils of long-lived, abundant, hard-bodied organisms dominate the fossil record. These fossils offer valuable information, such as an organism's physical form, behavior, and age. Studying the fossil record helps...