太陽系の初期に極度の酸素同位体比があった
Jérôme Aléon1, François Robert, Jean Duprat
1Centre de Recherches Pétrographiques et Géochimiques, 15 rue Notre Dame des Pauvres, BP20, 54501 Vandoeuvre-les-Nancy, France. aleon2@llnl.gov
Nature
|September 16, 2005
まとめ
新しい隕石の粒子は,極端な酸素同位体比を明らかにし,太陽の放射線が,複数の星ではなく,初期の太陽系の構成要素を形成した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)
- 惑星科学は惑星科学である.
- 天体物理学 天体物理学
背景:
- 隕石のような初期の太陽系材料の同位体組成は,それらの起源についての洞察を提供します.
- 惑星の物質における酸素同位体の変動は,多様な核合成または化学の歴史を持つ成分の混合に関連しています.
- 隕石の粒子の極端な同位体変動は,通常,プレソラー恒星の源に起因する.
研究 の 目的:
- 新しく発見された隕石の粒に含まれる極端な同位体組成物の起源を調査する.
- 太陽系初期の構成要素の同位体構成に起因する核合成過程を決定する.
主な方法:
- 隕石の有機物質に含まれる大量にシリコンが豊富な粒子の酸素とシリコンの同位体組成の分析.
- 観測された同位体比の比較と,恒星の核合成と太陽光照射モデルの予測.
主要な成果:
- これまで観測された中で最も極端な18O/16Oと17O/16Oの比率 (約. 10^-1). 10^-1). 10^-1). 10^-1). 10^-1). 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1. 10^-1.
- これらの粒子は,太陽のシリコンの同位体組成を示しています.
- 酸素とシリコンの両方の同位体は,単一の核合成または加工イベントを指しています.
結論:
- 観測された同位体組成は,単一のエキゾチックな進化した星,または若い太陽からのエネルギー粒子による環太陽ガスの照射と一致しています.
- この研究は,予測された組成と捕獲メカニズムとより良く一致しているため,太陽光照射仮説を好む.
- この発見は,太陽系初期における極度の同位体変動に対する複数の恒星の貢献に関する伝統的な見解に異議を唱えるものである.
さらに関連する動画
09:45Laboratory Simulation of an Iron(II)-rich Precambrian Marine Upwelling System to Explore the Growth of Photosynthetic Bacteria
Published on: July 24, 2016
09:31Preparation of Authigenic Pyrite from Methane-bearing Sediments for In Situ Sulfur Isotope Analysis Using SIMS
Published on: August 31, 2017
関連する概念動画
Conditions on Early Earth
Around 4 billion years ago, oceans began to condense on earth while volcanic eruptions released nitrogen, carbon dioxide, methane, ammonia, and hydrogen into the primordial atmosphere. However, organisms with the characteristics of life were not initially present on earth. Scientists have used experimentation to determine how organisms evolved that could grow, reproduce, and maintain an internal environment.
Conditions on Early Earth
Around 4 billion years ago, oceans began to condense on earth while volcanic eruptions released nitrogen, carbon dioxide, methane, ammonia, and hydrogen into the primordial atmosphere. However, organisms with the characteristics of life were not initially present on earth. Scientists have used experimentation to determine how organisms evolved that could grow, reproduce, and maintain an internal environment.
Mass 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...
Oxygenic 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...
Origin of Cellular Life
The origin of life on Earth is a complex and enigmatic event rooted in ancient biochemical processes and geological conditions. Experimental evidence supports the hypothesis that life began with the spontaneous formation of organic molecules such as RNA nucleotides, amino acids, and lipids under early Earth conditions. Factors like volcanic activity, intense UV radiation, and a reducing atmosphere without free oxygen likely facilitated these reactions. Hydrothermal vents on the ocean floor are...
Origin of Photosynthesis
Photosynthesis represents a fundamental biological process that transformed Earth's atmosphere and paved the way for complex life. Emerging roughly 3.4–3.8 billion years ago, the earliest photosynthetic organisms harnessed light energy to produce organic compounds. These anoxygenic phototrophs used electron donors like hydrogen sulfide (H₂S) or ferrous iron (Fe²⁺), rather than water, and did not release molecular oxygen (O₂) as a byproduct. Various groups, including green sulfur and purple...
