To begin the meeting our President Mark Phillips updated us on the upcoming Society programme. Mark also mentioned that our membership now stands at 180, the highest it has ever been in our history. He also pointed out that our on-line talks now attract a truly international audience.
In keeping with this trend our guest speaker was Patrick Barth, a PhD student from the University of St Andrews, who spoke to us about “ What makes a planet habitable”.
Patrick began with the basics of what is necessary for life as we know it on our own Earth, in particular liquid water, but he quickly expanded this to other factors such as stellar effects ( the type of star and the age of the star ), the planetary system involved ( the number of orbiting bodies, the presence of moons ) and the various properties of a given planet ( its atmosphere, size and mass, rotation, presence of a magnetic field ).
Fascinatingly we still do not know how the right conditions for life actually give rise to life itself, even on our own Earth, the only habitable planet we currently know of. There followed a quick tour of the Solar System, including Mars, Venus and the moons of the outer planets and a discussion of the chances of finding life or the signs of past life, in these places.
Only in the last 25 years we have discovered that other stars also have planetary systems and we now know of thousands of these Exoplanets. The possibility of life therefore in the wider universe has greatly increased. We were taken through a detailed explanation of the factors influencing the chance of life on exoplanets and the part that will be played by telescopes like JWST and future missions in the search for these “biosignatures”.
Patrick’s delivery and slides were exceptionally clear and helped to make sense of this relatively new and complex science.
Nigel Goodman