CAIの境界にある酸素同位体の変動は,太陽星雲内の循環を記録する
Justin I Simon1, Ian D Hutcheon, Steven B Simon
1Astromaterials Research Office KR111, NASA Johnson Space Center, Houston, TX 77058, USA. justin.i.simon@nasa.gov
Science (New York, N.Y.)
|March 10, 2011
まとめ
カルシウムとアルミニウムに富んだインクルージョン (CAI) の分析により,酸素同位体の大きな変化が明らかになりました. これらの発見は,CAIが複数の酸素貯蔵庫から形成され,初期の太陽星雲の環境変動を示唆することを示唆しています.
科学分野:
- 宇宙化学 (コスモケミストリー)
- 惑星科学 惑星科学
- イソトープ地球化学 イソトープ地球化学
背景:
- カルシウムとアルミニウムが豊富なインクルージョン (CAI) は,太陽雲の中で形成された最も初期の固体物質の1つです.
- その同位体組成を理解することで,初期の太陽系の状況についての洞察が得られます.
研究 の 目的:
- 特定のCAIとその周辺の鉱物帯の酸素同位体組成を調べる.
- 観測された同位体変動が,CAI形成と初期の太陽星雲環境に及ぼす影響を決定する.
主な方法:
- CAIとその鉱物マントルのマイクロメートルスケールの分析.
- 酸素同位体比の測定. 酸素同位体の比の測定. 酸素同位体の比の測定. 酸素同位体の比の測定. 酸素同位体の比の測定. 酸素同位体の比の測定.
主要な成果:
- CAIの外側の部分は,幅広い酸素同位体組成を示しています.
- 酸素イソトープの組成は系統的に変化し,CAIの限界に向かって減少し,その後,リムで非常に16Oに富んだものになります.
- 観測された変動性は,複数の異なる酸素貯蔵庫から形成されたことを示唆しています.
結論:
- CAIは,いくつかの酸素貯蔵庫から形成された可能性が高い.
- このデータは,太陽星雲の環境における早期の,短命の変動を裏付けている.
- これらの変動は,CAI輸送または太陽星雲のガス組成の変動によるものかもしれません.
関連する概念動画
01:26Oxygenic Photosynthesis
Oxygenic photosynthesis is a fundamental process in which light energy is harnessed to drive the oxidation of water, leading to the production of molecular oxygen (O₂), adenosine triphosphate (ATP), and nicotinamide adenine dinucleotide phosphate (NADPH). This process is essential for sustaining aerobic life on Earth and is primarily carried out by cyanobacteria, algae, and plants. The core of oxygenic photosynthesis lies in the thylakoid membranes, where chlorophyll pigments facilitate light...
01:21Isothermal Processes
A thermodynamic process that occurs at constant temperature is called an isothermal process. Heat slowly flows into the system or out of the system to maintain thermal equilibrium. Processes involving phase changes like water evaporation into steam or freezing water into ice at a constant temperature are examples of Isothermal Processes.
An ideal gas can also undergo isothermal expansion or compression.
For example, consider 1 mole of an ideal gas inside an isolated cylinder at initial volume V...
An ideal gas can also undergo isothermal expansion or compression.
For example, consider 1 mole of an ideal gas inside an isolated cylinder at initial volume V...
01:18Variation of Atmospheric Pressure
Change in atmospheric pressure with height is particularly interesting. The decrease in atmospheric pressure with increasing altitude is due to the decreasing gravitational force per unit area as we move away from the surface of the earth.
Assuming the air temperature is constant at a given altitude and that the ideal gas law of thermodynamics describes the atmosphere to a good approximation, one can find the variation of atmospheric pressure with height.
Let p(y) be the atmospheric pressure at...
Assuming the air temperature is constant at a given altitude and that the ideal gas law of thermodynamics describes the atmosphere to a good approximation, one can find the variation of atmospheric pressure with height.
Let p(y) be the atmospheric pressure at...
01:12Isotopes
Elements have a set number of protons that determines their atomic number (Z). For example, all atoms with eight protons are oxygen; however, the number of neutrons can vary for atoms of the same element. The sum of the number of protons and the number of neutrons is the mass number (A). Atoms with the same atomic number but different mass numbers are called isotopes. Elements can have multiple isotopes, for example, carbon-12, carbon-13, and carbon-14.An element's atomic mass, or weight, is a...
01:13Mass Spectrometry: Isotope Effect
Most elements exist in nature as a mixture of isotopes. The isotopes differ in weight due to their respective number of neutrons. The molecular weight of a molecule is different depending on the specific isotope of its elements involved. As a result, the mass spectrum of the molecule exhibits peaks from the same fragment at multiple positions. The positions of these mass signals depend on the mass differences between isotopes. Furthermore, the intensity of these signals is dependent on the...
01:21Isochoric and Isobaric Processes
A thermodynamic process that occurs at constant volume is called an isochoric process. According to the first law of thermodynamics, heat supplied or removed from the system is partially utilized to perform work and change the internal energy of the system. However, in an isochoric process, the volume remains constant. Hence, the work done by the system is zero. Therefore, the exchange of heat changes the internal energy of the system only.
Suppose 1000 g of water is heated from 40 degrees...
Suppose 1000 g of water is heated from 40 degrees...