The moon appeared approximately 4.5 billion years ago when a giant space object the size of Mars smashed into our planet. The size of the moon is around one-quarter of the size of the Earth, but a lot of things would change if it disappeared.
The gravitational pull of the Moon is pulling the oceans into a bulge at the equator. This drives the tides and affects sea levels across our planet, but it also slows down our rate of rotation. If the moon wasn’t around, the Earth would speed up until it was spinning around every six hours, which would make lethal winds of over 160 kilometres (100 miles) per hour.
The moon is also keeping the Earth stable. Without it, the axis of our planet would tip every few million years. First, the equator would point at the sun, but then this would change and the poles would face our star. Because of this, the climate would become so unstable, that life would struggle to adapt. In other words, the moon helped to make our world habitable.
