Nova Teoria sobre Criação da Lua!

The moon may have been adopted by our planet instead of descended from it.

If a new twist on a decades-old theory is right, conditions in the early solar system suggest the moon formed inside Mercury's orbit and migrated out until it was roped into orbit around Earth.

The idea flies in the face of scientific consensus, known as the giant impact hypothesis, which holds that the moon formed from red-hot debris left over after a Mars-sized object collided with Earth around 4.5 billion years ago.

However, the moon has several curious traits that go unexplained with that theory, and Robert Malcuit of Denison University has argued for decades for an alternative view of our moon's history.

Malcuit's version of events is tantamount to cosmic blasphemy, but scientists have recently found 4 billion-year-old minerals in Australia that suggest our planet was too cool to have sustained a cataclysmic moon-forming impact early in its history.

"Everything in the giant impact model is hot, hot, hot," he said. "It's incompatible with what we see in the geologic record. Earth is cool enough at that time to have ocean water on its surface."

Malcuit's computer modeling studies, which he has worked on since the 1980s, show that it is possible for Earth's gravitational pull to capture the moon.

At first, the moon's orbits would have been highly elliptical, swinging close to Earth and then far away about eight times a year.