Later tonight, scientists say a brighter than usual Jupiter will accompany the moon as they rest in the night sky. The spectacle will be best seen from the East Coast though it should be visible to most people around the United States. Jupiter’s photobomb of Earth’s moon will occur ahead of Wednesday’s penumbral eclipse.
Jupiter will be at a -2.5 magnitude brightness on Tuesday evening, contrasting the even brighter moon, which will be at -12.4 magnitude. Stargazers will have the opportunity to view the distant planet hanging next to tonight’s waxing gibbous until the next morning.
Meanwhile, the moon will be slightly darkened by Earth’s shadow on Wednesday—emphasis on the word slightly. Apparently the penumbra will be so faint that it will be nearly indistinct from a normal full moon.
We typically think of lunar eclipses in the umbral, which sees the moon move through the dark part of Earth’s shadow, turning it a copper red. The penumbral, however, is the shaded outer region of the shadow cast by Earth, which is much less exciting when comparing the two.
As The Washington Post notes, eclipses have families, and the one occurring tomorrow evening is relatively young—only a few hundred-years-old. It’ll be another few hundred years before this specific event creates a total lunar eclipse. The next total lunar eclipse, however, which is part of Saros 124, will occur early in 2018.