The search for extraterrestrial life rages on but we have not been able to find any life forms in places we have investigated so far. Humans have been on the Moon and extensive research has been done on Mars but we are yet to find any evidence.
That is not to say that we won't ever find life out there or even in these places where we have been looking. Who knows, one day, we'll all get a huge surprise which will rattle the entire planet and might change our understanding of life itself.
Anyways, in our search for extraterrestrial life forms, there is one thing that we need to be extra careful about. When we send humans or rovers or any other machines on other planets or their moons, we must make sure that we do not contaminate their surfaces with life from Earth.
Just recently, the crashed Israeli moon lander did exactly that by introducing tardigrades to the lunar surface and it remains to be seen exactly what consequences this might have.
Tardigrades On Lunar Surface
The Israeli lunar lander called Beresheet, was carrying thousands of tardigrades when it crashed into the lunar surface on April 11. Tardigrades are microorganisms and are often called 'water bears'. They are the toughest animals on the planet and it is virtually impossible to kill them.
They can survive in temperatures as low as 328 degree Fahrenheit and also in space! In fact, tardigrades are reportedely found living on the outside of the International Space Station.
The tardigrades on the Israeli lander were dehydrated first and so it is not clear whether or not they will survive for a long period of time and they certainly won't be moving around, colonising the Moon, but experts say that it is possible they could be revived for years after the dehydration procedure.
So, in a way, there is life on the moon now, left behind by us and any future human travellers could check up on them if they managed to survive. If there was one species needed to be chosen for a scenario like this, tardigrades are it.