He can tell you all about meteorite ALH84001, the rock from Mars, that may — or may not — show signs of organic life. He knows all the arguments for and against the claim that there are fossilised microbes in this rock that do not derive from earth.
At lunch we were saying how frustrating it was that we still have no idea if there is other intelligent life in the universe.
We had fun coming up with the things we would like to know about intelligent creatures living on another planet.
Do they eat other creatures? (Jake)
Do they have pets? (Jake)
Do they train other animals to do jobs? Like guide dogs? (Maureen)
Will they find us physically repulsive? (John)
Do they tell stories? (John)
How do they reproduce? (Maureen)
What is beautiful to them? What is ugly? (John)
Do some things they do cause embarrassment ? Like farting or belching? (Jake)
How do they go to the toilet? (Jake)
Do they have gods? Or did they once believe in gods? (John)
How many intelligent species destroyed themselves when they were able to develop weapons of mass destruction?) (John).
Professor Close does not hold out much hope for other intelligent life.
He thinks we may derive from hypothermophilic life forms that live around the hot black smokers in our deep oceans. They are called extremophiles.
Another type of extremophile is a rock eating microbe that lives in rocks and can go dormant for millions of years. According to Professor Close, this means the idea of panspermia is feasible because such life forms could be carried on meteorites or survive bombardments from space.
For scientists the really big question is about how complex organic molecules were formed, in other words how life as we know it originated.
That remains a mystery: because complex organic molecules could not have been formed by chance.