Scientists at Durham University in the UK have found out how the Earth’s collision with a minor planet 4.5 billion years ago led to the Moon’s appearance. The Earth satellite formation process was modeled using high-performance computing on a Dirac supercomputer. The discovery of the mystery of the Moon’s appearance is reported in an article published in the Royal Astronomical Society Monthly Notices.
Researchers tracked the fate of the substance ejected into space for four days after the collision of Earth and Theia, the size of Mars. Various scenarios were taken into account, depending on the minor planet’s speed of rotation around its axis. It turned out that if the Moon did not rotate, the collision leads to releasing a substance that makes up 80 percent of the Moon’s mass. This substance, under the influence of its own gravity, forms a celestial body. At a low speed of rotation, a moon-like object is also formed.
The resulting block, which begins to fly around the Earth, grows after the collision, “feeding” on material from the debris disk surrounding the planet. It has an iron core and an outer shell formed by the substance of Earth and Theia.