So, life on Mars...

[Bohandas]

it's almost exactly the premise of Night of the Living Dead (except that in Living Deadmis was Venus and not Mars)

 

[The Firebird]

Isn't that how every horrot movie starts?

(but more seriously, they'd get contaminated)

The current Mars samples were slated for return in the 2030s, but that is up in the air for budgetary reasons. There have been successful analyses of several asteroids which had material returned to Earth recently--Hayabusa2, and more recently OSIRIS-REX. In short they have to be very careful, but it is possible (some of my colleagues were involved in those analyses).