保护地球，探索宇宙，发现文明
2022年8月13日 Herschel Crater on Mimas Image Credit Cassini Imaging Team, ISS, JPL, ESA, NASA Explanation: Mimas, small 400 kilometer-diameter moon of Saturn, is host to 130 kilometer-diameter Herschel crater, one of the larger impact craters in the entire Solar System. The robotic Cassini spacecraft orbiting Saturn in 2010 recorded this startling view of small...
2021年7月30日 Mimas in Saturnlight Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA Explanation: Peering from the shadows, the Saturn-facing hemisphere of Mimas lies in near darkness alongside a dramatic sunlit crescent. The mosaic was captured near the Cassini spacecraft’s final close approach on January 30, 2017. Cassini’s camera was pointe...
2021年05月31日 Mimas: Small Moon with a Big Crater Image Credit & Copyright: NASA, JPL-Caltech, Space Science Institute, Cassini Explanation: Whatever hit Mimas nearly destroyed it. What remains is one of the largest impact craters on one of Saturn’s smallest round moons. Analysis indicates that a slightly larger impact would have destroyed Mimas ent...
2019 October 18 Interstellar Interloper 2I/Borisov Image Credit: NASA, ESA, and D. Jewitt (UCLA) et al. Explanation: After the 2017 detecton of 1I/’Oumuamua, comet 2I/Borisov has become the second recognized interstellar interloper. Like ‘Oumuamua, Borisov’s measured hyperbolic trajectory and speed as it falls toward the Sun confirm that it...
2019 October 17 Moons of Saturn Image Credit: Cassini Imaging Team, SSI, JPL, NASA Explanation: On July 29, 2011 the Cassini spacecraft’s narrow-angle camera took this snapshot and captured 5 of Saturn’s moons, from just above the ringplane. Left to right are small moons Janus and Pandora respectively 179 and 81 kilometers across, shiny 504 kilom...
2019 August 3 Mimas in Saturnlight Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA Explanation: Peering from the shadows, the Saturn-facing hemisphere of Mimas lies in near darkness alongside a dramatic sunlit crescent. The mosaic was captured near the Cassini spacecraft’s final close approach on January 30, 2017. Cassini’s camera was poi...