What are the dangers of finding life on other planets?
One of the real dangers of playing this game of looking for life elsewhere is that, were you able to go somewhere where you found it and you want to study it in detail, then you've got to bring it back. Now, the minute you start putting things from one environment into another environment you have the potential to create a huge problem. It starts further back than bringing a sample. If we are going to Mars looking for life, if we take terrestrial life there, and take it and put it into a delicate ecosystem where life might have a very tenuous hold, we might wipe it out. The example is that there were no rabbits in Australia in the early eighteenth century, and nineteenth century. Ships took rabbits there because they were a quick source of meat for food. The ships took them there and the next thing you know, you've got a rampant problem with rabbits. There are other examples like that. Now, so if we were to take terrestrial life to Mars, it might just completely take over from the local life. The converse is true. If we brought samples back from Mars that had active organisms on them, then they might be adapted to very, very harsh conditions. Put them on earth into a very benign situation, and they might run riot, which could be worse than foot-and-mouth, Asian flu, avian flu, and you name it. So, it is a big responsibility. It's called “planetary protection.” We have to protect where we go. We have to protect earth. So, these are threats that I know about, and these are things for which we feel very responsible in doing our science. We were very, very careful not to do it with Beagle, and we're making sure that other missions don't do it either.
