Post

Paul Byrne
@theplanetaryguy.com

Astrophotographer Adam (AJ) Smadi caught this image a few hours ago from Washington state. A thin crescent Moon, sunlight illuminating the rugged lunar surface. And 2,400 times farther away—and on the other side of the Sun—mighty Jupiter, and its moons Io (left) and Ganymede (right).

Paul Byrne
@theplanetaryguy.com

See the image on Instagram here: www.instagram.com/aj.smadi/p/D... I verified the position of each of these four elements (the Moon, Jupiter, Io, and Ganymede) with NASA's Eyes on the Solar System. The positions, lighting, and phases all check out. Every indication is that this is real.

32 reposts511 likes

Paul Byrne
@theplanetaryguy.com

It's worth emphasising that the reason we see the full disk of Jupiter but a crescent Moon is because Jupiter is on the other side of the Sun. Indeed, we cannot see a crescent Jupiter from Earth; we'd have to be beyond it for that to work. A beautiful illustration of how the Solar System works.

kmbailey59.bsky.social
@kmbailey59.bsky.social

Your first sentence confused me, but your second sentence clarified, sort of. It doesn't matter which side of the sun Jupiter is on, it's always full. The only planets that go through phases as viewed from earth are Mercury and Venus. If you're on Mars, the earth has phases too.

(starhag)
@gwenforr.bsky.social

That is not Callisto. We wouldn’t see it that far above Jupiter. Callisto is actually just out of frame to the right, and Europa is behind Jupiter.

(starhag)
@gwenforr.bsky.social

Callisto is out of frame to the right in this pic. The last pic on the Instagram post and you can see it there, faintly. It’s the darkest of the four big ones.