Venus figures
Scientists have suggested that Venus may have destroyed a possible former moon because of its slow rotation. Mercury and Venus are the only planets in the Solar System without moons. Venus is believed likely to have experienced major collisions, as Earth did, in the system that formed approximately 4.5 billion years ago.
Earth measurements
A team led by Stephen R. Kane of the University of California, Riverside, developed a simulation that models gravitational interactions and was validated using the Earth-Moon system.
While Earth rotates in approximately 24 hours, one rotation of Venus takes 243 Earth days; Earth rotates more than 200 times faster than Venus.
Venus calendar
Earth’s rotational energy is pushing the Moon away. Mirrors left by the Apollo 11 astronauts in 1969 show that the Moon is moving 4 centimeters farther away each year. According to the simulations, even if Venus initially rotated faster, if its speed was low enough, a moon formed by a collision may have moved closer to the planet and broken apart.
The study, published yesterday (September 14) in The Astrophysical Journal, states that this may have occurred within Venus’s first 1 billion years.
Venus details
In most of the trials, the moon collided with Venus. Larger moons were found to slow the planet’s rotation more and be destroyed more quickly. It is not known for certain whether Venus ever actually had a moon.