【宇宙】ハッブルが捉えた木星面を通過するガリレオ衛星の「トリプルトランジット」
The Wide Field Camera 3 on NASA’s Hubble Space Telescope has captured a rare look at three of Galilean moons
– Io, Callisto, and Europa – zipping across the banded face of Jupiter.
The Hubble image on the left (unlabeled at top left, labeled at bottom left) shows the beginning of the event,
which took place on January 24, 2015. From left to right the moons Callisto and Io are above Jupiter’s cloud tops.
The shadows from Europa (not seen in the image), Callisto, and Io are strung out from left to right. Near the end of
