New Study Says Venus Destroyed Any Moon Within 1 Billion Years
Updated
Updated · Universe Today · Sep 12
New Study Says Venus Destroyed Any Moon Within 1 Billion Years
3 articles · Updated · Universe Today · Sep 12
Summary
Modeling in a new Astrophysical Journal paper finds Venus likely lost any early moon within its first billion years, making the planet’s moonless state a natural result of tidal evolution.
A 243-day retrograde spin is central to that outcome: the simulations show only a narrow set of cases let a moon survive, mainly if early Venus spun fast and the moon was no heavier than Earth’s.
At about 2.85 Venus radii—roughly 17,000 km from the planet’s center—a Venus moon crossing the Roche limit would be torn apart into debris and eventually fall onto the planet.
NASA’s DAVINCI mission, planned for launch by the end of this decade, could test the idea by measuring noble gases and isotopic ratios that might preserve traces of a long-destroyed moon.
The work also suggests slowly rotating, close-in Venus-like exoplanets should generally be moonless, with possible consequences for climate stability and long-term habitability.