The Hubble Space Telescope has been used to study NGC 1052-DF2 — a galaxy that is lacking dark matter. Credit: NASA's Goddard Space Flight Center ...

While third-party grading services and their population reports have helped collectors gauge rarity, the costs of grading have influenced which coins get submitted—introducing biases that numismatists ...

天文学家揭示了有关小星系 NGC 300 的新细节，挑战了现有的星系形成理论。通过观察古老的、金属贫乏的恒星和延伸超过 100000 光年的巨大恒星流，该研究表明，即使是矮星系也会从周围环境中吸积质量，就像它们的大星系一样。 NGC 300 是宇宙中一个相对孤立区域的小星系。它距离地球约 600 万光年，是银河系的近邻之一。图片来源：ESO ...

Soldiers recently evaluated the Tactical Computing Environment and other mission command technologies during the Expeditionary Command Post S&T Field-based Risk Reduction Exercise at CERDEC's ...