´óÏó´«Ã½

It's an exciting few days for space watchers as Mars will be coming the closest it's been to Earth for 15 years.

The phenomenon is called a Mars close approach, which is when the red planet and Earth come nearest to each other in their orbits around the Sun.

Mars will still be 35.8 million miles away though, so there's certainly no danger of it bumping into us.

When a close approach happens, a rumour often flies around that Mars will look as big as the Moon in the night sky, but this isn't true!

To start with, on 27 July, something called a Mars opposition will happen, when Mars, the Earth and the Sun all directly line up. This is when Mars should start to come into view from Earth.

Then, on 31 July, the Mars close approach will happen, so this will be your best chance to take a look! Although the planet will still be visible for a while after this, before its orbit takes it further away again.

Nasa has said that there is currently a dust storm which is affecting the whole planet, so this may make seeing details on Mars a little more difficult for astronomers.

Of course, you will get the best look at the close approach through a telescope, but if you don't have one and you want to see the planet closer up, then it could be worth contacting your local planetarium or astronomy centre to see if they're holding any special events for it.

A Mars close approach happens about once every 26 months (just over two years). This is why you will often see Mars missions launching every two years. You can find out everything about the latest mission, which blasted off in May 2018, here.

The reason that the distance between Earth and Mars changes like this is because they have elliptical (egg-shaped) orbits.

The gravitational pull by other planets also constantly changes the shape of their orbits a little bit, with Jupiter especially influencing the path that Mars takes around the Sun.

In 2003, the red planet came 34.8 million miles close to Earth, which was the closest it's been to us in 59,619 years. It won't come that close again until the year 2287!

The next Mars close approach is on 6 October 2020 when the planet will be 38.6 million miles away.

July is a very exciting time for space fans, with the longest total lunar eclipse of the century happening at the end of the month too.