Astrobiology: Understanding the Origins of Life - Professor Nigel J Mason OBE – Wednesday 20th July

A diverse audience of fifty-four was treated to yet another thoroughly entertaining WAS evening. Professor Mason’s passionate, humorous and interactive talk was enjoyed so much that members wanted to communicate their compliments before the night was out.

The talk focused on key questions. Where and how did life begin on Earth? Is there life elsewhere in the Universe? Are the conditions for sustaining life common throughout the Universe? How is pre-biological material made?

The Professor often encouraged engagement from his audience, occasionally looking to trip them up! 

The make-up of DNA consists of just a few atoms: carbon, hydrogen, oxygen, nitrogen, and phosphorus. Combinations of these atoms form the sugar-phosphate backbone of the DNA -- the sides of the ladder. Other combinations of the atoms form the four bases: thymine (T), adenine (A), cytosine (C), and guanine (G). The question is, how were they made?

Aleksandr Oparin was a Soviet biochemist notable for his untested theories about the origin of life, and for his book The Origin of Life. In the 1950's, biochemists Stanley Miller and Harold Urey tested his theories, conducting an experiment which demonstrated that several organic compounds could be formed spontaneously by simulating the conditions of Earth's early atmosphere. 

The first carbon-containing molecule detected in the interstellar medium was the methylidyne radical (CH) in 1937. Since then an ever increasing number of molecules have been detected. Now there are well over 100 and a fair proportion of these have ten or more atoms. 

How (and where) are smaller molecules then made into larger ones? We don’t know yet. The Prof took us on a tour of the history of Astrobiology and how we might discover whether there really is intelligent life out there.

The earth has not been here long enough for the biochemistry to evolve to the way it is now, which gives rise to the thought that the origins of some of the functional biological molecules may be extra-terrestrial, for example from meteorites or other early collisions.

Professor Mason commented, ‘It was a pleasure to talk to the Wycombe Astronomical Society. I was impressed by the turn out on such a fine evening and by the insightful and interesting questions. It was nice to see some younger members who asked and answered questions so well.’