Did Venus Swallow Its Moon?

Damia Bouic, an amateur image processor, combined images of Venus from Japan’s Akatsuki mission to create this composite image.
Credit: JAXA / ISAS / DARTS / Damia Bouic

It’s a question that has perplexed planetary astronomers for decades: Why does Venus — so similar in size to Earth and not all that far from Earth’s orbit — have no moon, while our planet has such a relatively large one? Earth’s Moon likely formed after a massive collision early in solar system history. But according to calculations, Venus should have been even more likely than Earth to have experienced such a catastrophic crash during its formative years. Yet today it has no moon at all.

Now, a series of simulations published in the September 20th Astrophysical Journal, have demonstrated that Venus might once have had a moon — but the planet’s relative proximity to the Sun and its massive atmosphere both created conditions under which no moon could have survived. If there ever was a moon, it would have disintegrated and fallen back to the surface long ago.

(Source: skyandtelescope)