Do we have to worry about contaminating Mars?
Whenever we send a probe to Mars we spend a lot of effort scrubbing it to make sure that there aren't any terrestrial microbes hitching a ride to the red planet. There's a lot of sense in doing that. Scientists are curious as to whether Mars has any native life. If we spread earthly bugs to Mars then it might be hard to tell if whatever we find had its origins on Mars or Earth. But I wonder if the cat isn't already thoroughly out of the bag. Way back in '84 some scientists found a meteorite that they realized had initially come from Mars. Some larger rock had hit Mars 17 million years ago and this future meteorite had been blasted out of the crater so hard it actually left Mars altogether. For a very long time it orbited the sun until eventually, 11,000 years ago, it managed to land on Earth. All well and good but you'd think that any rock being blasted off a planet would be pretty thoroughly sterilized in the process. Some years after the meteorite was