An astrophysicist has proposed a new theory to explain why Venus has no moon of its own, suggesting the planet effectively consumed one long ago. The theory was reported by the Independent.
Stephen Kane, an astrophysicist at the University of California, said in a new publication that Venus's extremely slow rotation on its axis would have doomed any natural moon that once orbited the planet, pulling it into a gradual inward spiral that ended in a collision with its parent body.
Kane described the process as a form of "celestial cannibalism," arguing that Venus was ultimately unable to hold on to a moon. He said it is most likely that Venus did once have one.
What the models show
According to Kane, computer models built on planetary physics, which simulate the gravitational mechanics of hypothetical Venusian moons of various sizes, all point to the same outcome: sooner or later, every one of them would fall into the planet. He said this probable engulfment likely took place within the first billion years of Venus's history.
Competing theories
Scientists had previously believed either that Venus never had a moon in the first place, or that it once had one that was destroyed in a powerful collision with another celestial body.
Kane believes Venus, during its formative period, could not escape the kind of destructive collision with another protoplanet that is widely thought to have led to the formation of the Moon.
Why Venus runs hotter than Mercury
Popular Science has separately explained why Venus is hotter than Mercury despite being farther from the Sun. Scientists believe Venus was most likely once a tropical world. Mercury was previously the hottest planet in the solar system, but as the Sun gradually grew brighter, a runaway greenhouse effect pushed Venus's surface temperature well above Mercury's.
