Did we already kill some Martians?

According to a geology professor the Viking space probes that visited Mars 30 years ago may have found alien microbes and inadvertently killed them:

Scientist: NASA found life on Mars – and killed it

“Given the cold dry conditions of Mars, life could have evolved on Mars with the key internal fluid consisting of a mix of water and hydrogen peroxide, said Schulze-Makuch. That’s because a water-hydrogen peroxide mix stays liquid at very low temperatures, or -68 degrees Fahrenheit, and doesn’t destroy cells when it freezes. It can suck water vapor out of the air.

The Viking experiments of the 1970s wouldn’t have noticed hydrogen peroxide-based life and, in fact, would have killed it by drowning and overheating the microbes, said Schulze-Makuch. One Viking experiment seeking life on Mars poured water on soil. That would have essentially drowned hydrogen peroxide-based life, he said. And different experiment heated the soil to see if something would happen which would have baked Martian microbes.”