Image copyright ISRO Image caption India's Mars Orbiter Mission got straight down to work on arriving at the Red Planet

The space agencies of India and the US have signed an agreement on future co-operation at Mars and at Earth.

The nations have just put satellites in orbit around the Red Planet, and plan a joint radar spacecraft to study our home world in 2020.

But the charter signed by Nasa and the Indian Space Research Organisation will also examine additional opportunities.

The agreement was signed by agencies' two leaders at the 65th International Astronautical Congress in Toronto.

India's Mars Orbiter Mission (MOM), also known as Mangalyaan, arrived in orbit at Mars on 24 September to image the planet and study its atmosphere.

It was preceded by the American Maven satellite by two days. the US orbiter will also investigate the Mars' atmosphere.

The Toronto charter sets up a working group, which, among its activities, will explore ways for the two Red Planet missions to work together.

The joint Nasa-Isro Synthetic Aperture Radar mission (NISAR) will detail land change on Earth.