There's no word from Curiosity on whether Mars has life or not or whether it ever had. Any results from the rover, if they are coming, won't be coming for a while now. But that isn't stopping scientists from trying to figure out whether life could survive in the conditions found on Mars.
The latest such research shows some interesting results, some bacteria were able to survive conditions somewhat similar to those found on Mars today.
In their research, biologists took soil samples from the Siberian permafrost, deep down enough that they haven't been disturbed for thousands of years.
They then grew the micro-organisms found there under normal conditions, enough for them to develop. They then started to make the conditions harsher, dropping the temperature, the air pressure and eventually removing most of the oxygen.
As expected, most of the bacteria died out, but not all. From the thousands of colonies, only six survived, all from the genus Carnobacterium.
Carnobacterium have been found growing on frozen, vacuum-packed meat, which is how they got the name, so the fact that they survived isn't all that surprising.
Still, it shows that life can adapt to extreme circumstances. This doesn't necessarily mean that there is life on Mars or that life could survive on Mars.
There are plenty of conditions that haven't been accounted for, the solar and cosmic radiation or the extreme desiccation. So if life is to survive on Mars today, it's going to be even tougher than this.
But, while the study didn't prove that there could be life on Mars, it did prove that bacteria from Earth could potentially survive the trip there.
This is something that missions to Mars that are trying to find signs of life there, like Curiosity, will need to be even more careful about than they have been so far.