One example of spacecraft that used solar energy is Rosetta, which was launched by the European Space Agency (ESA) in 2004 to investigate the structure of a comet. A ‘lander module’ called ‘Philae’ was set onto the surface of the comet to find out what it was like, and this also used solar energy (this was not a ‘rover’ because it was designed to stay still).

The Rosetta spacecraft used an array of solar cells to capture the energy of the sun and convert it to usable energy.

Solar cells are thin, plate-like structures which are able to capture the energy of the sun. They come in a range of sizes, and are usually made of silicon

As you can see in the picture, solar cells are now commonly set up in fields in large numbers, and they can also be found on the roofs of houses.

Note that there are different sorts of solar ‘panels’ on roofs and elsewhere. Some consist of solar cells, but others are panels containing water which is heated up by the Sun.

Hopefully, solar energy will help you and the devices you might use as you start to explore Mars. But we can’t always rely on solar energy: during the Rosetta mission, Philae landed oddly on the comet it was meant to study. Scientists believe that it landed in a shaded part of the comet with very little sunlight.

Unfortunately, Philae was not able to use solar power, and it lost contact with Rosetta when its batteries ran out after two days. Though it carried out some tests on the comet surface, it was unable to carry out most planned activities.