Scientists are hypothesizing that if there was life on Mars, it would likely be hidden inside deep underground caves.
NASA jet engine research scientist Vlada Stamenković explained the theory of underground life at Mars at a recent space event.
This hypothesis was put forward by NASA experts and the agency would send a new autonomous ship to the red planet next summer.
Speaking at the conference, Stamenković said: "The surface of Mars is a highly oxidized, heavily radioactive environment where liquid water does not really stabilize for a long time. This is the worst place for "Search for places to live on Mars. Groundwater could be the only habitat for survival on Mars, if it still exists today."
The surface of Mars is cold, dry and has a lot of radiation. Underground life may be easier for life forms and there may be some forms of stable water supply.
Some scientists think that new generation robots should be built that can try and explore the cave system on Mars.
In fact, the problem of making agile robots to penetrate all these potential caves will be expensive and complicated.
However, Stamenković proposed that NASA could use a movers to sense groundwater or chemicals related to life from the surface. This makes it easy to target specific areas where life is most likely to be found.
NASA plans to send the WED self-propelled ship to Mars later this year. The plan is for this space probe to collect new events of survival or extinction and send Mars samples back to Earth. NASA also plans to send humans to Mars in the mid-2030s.