Moon may have originated from Venus, after earth’s gravity captured its natural satellite from the planet, a new theory on lunar history suggests.
Moon may have originated from Venus, after earth’s gravity captured its natural satellite from the planet, a new theory on lunar history suggests. The theory is in contradiction to the belief that the earth’s moon formed some 4.5 billion years ago when a planet-size body slammed into nascent earth at high speed. “I think part of the key to (understanding) the Moon may be that Venus has no moon, and we certainly have to study it (Venus) more,” said Dave Stevenson, professor of planetary science at Caltech University, who proposed the Venus idea. The “moon capture” theory assumes that earth used its gravity to attract a pre-formed space body into its orbit, thus making a satellite of this object. However, the geochemical composition of the moon and earth likely trips up this theory, Space.com reported. Analyses of the lunar rocks brought back by Nasa’s Apollo Moon landing missions have shown that the satellite has an isotopic composition very similar to that of earth. If both moon and earth have very similar isotopes, it makes the capture theory difficult to maintain, said Alex Halliday, head of science at Oxford University. “The reason why it’s interesting is that earth and Venus are close to each other. They have similar mass, and people think they have probably formed in a similar way,” he said.
