In July last year, the three space probes started from Earth.
After this addition, there will be a total of eight functioning space probes in orbit around Mars and three on the planet's surface.
- It is fun to welcome more space probes to Mars, says Mats Holmström, associate professor and researcher at the Institute of Space Physics in Kiruna.
Join the Swedish instrument
Mats Holmström is responsible for a Swedish instrument, Aspera-3, which sits on the European probe Mars Express and has been in orbit around Mars for 18 years.
It was the first European space probe to another planet.
- With it, we have above all wanted to find out where the water that once existed on Mars has gone, says Mats Holmström.
Learn about the earth at the same time
The task of the probes and ground vehicles is to teach us more about the planet that was once very similar to our own.
By doing so, we can also learn more about the earth.
- In the beginning of the solar system, Venus, Mars and Earth were quite similar to each other.
By learning more about how Mars has evolved, we can also learn more about what has happened to the earth historically and what can happen in the future, says Mats Holmström.
Play the clip to hear Mats Holmström tell us more about why we want to investigate Mars and what we can learn.