标签： 杰纳斯

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...