[align=justify][box_out][box_in] The binary planet hypothesis—that Earth and the Moon formed simultaneously by the accretion of smaller objects—does not explain why the Moon’s iron core is so small relative to the Moon’s total volume, compared with Earth’s core relative to Earth’s total volume. According to the giant-impact hypothesis, the Moon was created during a collision between Earth and a large object about the size of Mars. Computer simulations of this impact show that both of the objects would
...
...
