CaSSIS mission: The camera capturing Mars' craters and canyons

It is a busy time for Mars at the moment.

This month the Red Planet entered its new year, what is known as Year 36, and it has not long been overtaken by Earth in its orbit of the Sun.

The distance between Earth and Mars constantly changes because of their different speeds around the Sun, therefore the optimum launch window for missions is just once every 26 months when the planets come closest together.

Many are anticipating the touchdown of Nasa's Perseverance rover - the most sophisticated vehicle ever sent to land on a planet - on 18 February.

However, the Red Planet is already being closely observed.

Since its launch in 2016 and its subsequent orbit insertion around Mars, an instrument named the Colour and Stereo Surface Imaging System (CaSSIS) has been used to enhance scientists' knowledge of the planet's surface.

The camera is travelling with the European Space Agency's (Esa) Exomars Trace Gas Orbiter, which is studying methane and other rare gases in the Martian atmosphere.