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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).

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.

Seems like a fitting image on the 60th anniversary of Star Trek.

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.

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.

um, would you have bandwidth to post a little sketch illustrating this? I can't quite wrap my head around it. (Sorry if this is very presumptuous).