Mars' ancient atmosphere may not have had much oxygen after all
There may have been no oxygen in the atmosphere of ancient Mars after all, a new study has found, but don't despair, there still could have been living creatures crawling on the planet.
TroibNews 
There may have been no oxygen in the atmosphere of ancient Mars after all, a new study has found, but don't despair, there still could have been living creatures crawling on the planet.
