Venus May Have Devoured Its Moon, Scientists Find

Astrophysicist Stephen Kane of UC Riverside published a study in The Astrophysical Journal suggesting Venus once had a moon that spiraled inward and crashed into the planet due to its slow 243-day rotation. The work doesn't prove a moon existed, but explains its absence without a catastrophic impact.

• Venus rotates once every 243 Earth days — too slowly for a moon to stay in orbit
• Simulations showed the moon would inevitably crash into the planet in every scenario
• About 80% of Venus's surface is younger than 1 billion years, erasing its geological record
• Findings matter for exoplanet habitability: slow rotation dooms moons to fall