Ability of planet to form moon affects its habitability: Study

Moon is not just a pretty thing in the night. It influences tides and has effects that help the perpetuation of life on Earth. Because it's a junior member in its partnership with Earth, it's often easy to overlook our only natural satellite when we gaze into space.

But now, a study says that ability of a planet to form a moon may be associated with the habitability of the planet.

Moon had formed due to a cataclysmic collision between nascent Earth and a Mars-sized planet called Theia. The unimaginably catastrophic collision resulted in ejection of large amount of material in space around Earth. Some of this material was vapourised while remaining started revolving around the Earth in form of several moonlets. In time, these moonlets joined together to form the Moon as it is today.

Scientists from the University of Rochester say that whether a moon would form after collision between two planets depends on their size. If planets a certain times larger than Earth collide, then probability of Moon formation is very less. This is because a collision between these planets vapourises almost all of the material ejected as a result of the collision. The vapour, though ejected in space around the planet experiences a drag and moonlets formed due to such material fall on the planet. Thus a moon is not formed.

Earth's Moon has a great effect on things on our planet. It controls tides. Due to the large size of the Moon, it controls size of day on Earth. It stabilises Earth's axis of rotation. It also stabilises Earth's mild climate.