Life Beyond Earth

What a habitable planet is changes with the kind of life and the age of the planet. There was a time Earth was without oxygen, and so would not have been habitable for us, but was habitable for many kinds of microbes. Now that Earth's surface has lots of oxygen, it's habitable for us, but not for most of those same microbes. Life can also transform its surroundings, for good or for ill, maintaining habitable conditions in some instances and destroying habitability in others. In this talk, Dr Paul Rimmer discusses all of these possibilities and how they influence the ongoing search for life elsewhere in our solar system, and the future search for life on planets around other stars.

It is now ~30 years since we have known that our planetary system is not alone. Astronomers have since discovered over 5000 exoplanets. While some of these do reside in what is considered to be their star's "habitable zone", none is a true Earth analogue. Thus the hunt for an exo-Earth continues, as does the search for evidence of life on the exoplanets we do know. Remarkably, we are tantalisingly close to being able to answer not only how common exo-Earths are, but also how common it is for these to host life. Over the next decades we can and will build the telescopes that will answer these questions, and we may also find signs of life in places where we were not expecting it. This talk by Professor Mark Wyatt will describe this quest and what we have learned so far.