太陽系外から飛来したある彗星において、これまで太陽系内で観測されたどの天体よりも重水素を豊富に含む水の割合が劇的に高いことが明らかになった。この発見は、同彗星が我々の太陽系近傍よりもはるかに低温の環境で形成されたことを示唆している。研究チームは2基の主要な望遠鏡の観測データを用いてこの測定を行った。
3I/ATLASとして知られるこの天体は、太陽系内で確認された3番目の星間天体である。天文学者らが1年足らず前に発見し、直ちに詳細な追跡調査を開始した。ミシガン大学の研究チームがその水の組成を分析したところ、重水素の濃度が太陽系の彗星より約30倍、地球の海洋より約40倍高いことが判明した。
Astronomers using the James Webb Space Telescope have detected water in the interstellar comet 3I/ATLAS with deuterium levels 30 to 40 times higher than in Earth's oceans. This heavy hydrogen ratio exceeds that of any known solar system comet by at least 10 times. The findings suggest the comet originated from a cold, distant region around an ancient alien star.
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NASA's Swift Observatory has detected water vapor from the interstellar comet 3I/ATLAS, marking the first such observation for an object from outside our solar system. The comet, the third confirmed interstellar visitor, was producing water at a rate of 40 kilograms per second when it was nearly three times farther from the sun than Earth. This discovery provides insights into the chemistry of distant planetary systems.
Researchers at the University of Tokyo have created an ensemble of eight climate models to trace water circulation worldwide using isotopic fingerprints. This method combines data on heavier hydrogen and oxygen atoms that shift predictably as water evaporates and travels through the atmosphere. The approach improves understanding of extreme weather and climate change impacts.
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Astronomers have conducted a thorough search for radio signals from the exoplanet K2-18b, a potential water world 124 light years away, but detected none indicative of advanced life. The planet previously sparked interest due to possible atmospheric signs of life, though those claims were later questioned. This latest effort used powerful telescopes to scan for transmissions similar to Earth's.
New research indicates that hidden oceans on icy moons around outer planets may boil due to tidal heating, explaining unusual surface features. The study, published in Nature Astronomy, focuses on smaller moons like Enceladus, Mimas, and Miranda. Lead author Max Rudolph from UC Davis highlights the processes shaping these worlds over millions of years.