By Duncan Alfreds
News24
It is likely that scientists will find extraterrestrial life, but the chances of it being intelligent, or even multi-celled, are remote, an astronomer has said.
“In our solar system I think there’s every chance that we will find things like bacteria – life at that level somewhere else. Multi-celled life, I think, is unlikely,” Dr Robin Catchpole told News24.
Catchpole works at the Institute of Astronomy in Cambridge, and is formerly a senior astronomer at the Royal Observatory.
He is presently giving a summer school at the University of Cape Town on “From Here to the Edge of the Observable Universe”.
Astronomers have, in the last 30 years, been more accepting of the idea that life may occur elsewhere in the universe.
Technology
“There’s almost a sort of philosophical point that we don’t see ourselves as unique in the universe perhaps in the way that we used to.
“In the last 100 years since Darwin really we’ve seen that we are related to all the other living things. So we would expect not only to find ourselves, of course, but we would expect and anticipate finding life elsewhere,” Catchpole said.
Technology has allowed astronomers to explore more of the universe and radio telescopes, in particular, have assisted in expanding knowledge.
“With radio telescopes we’ve discovered evidence of molecules – the basic precursors of life – all over the place in interstellar clouds. The more we look, the more we find,” said Catchpole.
In the past, it was thought that planets around stars were a rare phenomenon, but advances in astronomy have shown that not only are planets common, they are even present around binary stars, as in the Star Wars movies.
“Indeed, work done in South Africa itself is helping to find planets around stars and we think now they’re probably the rule, rather than the exception,” Catchpole said.
“It was really the technology that led us to discover the first planets because, in very rare cases, we don’t observe the planet itself,” he added.
Methods
Astronomers use three common methods to detect planets: Astrometry, that measures the star’s position and monitors it for a “wobble” that would indicate the presence of a body exercising a gravitational influence.
In the transit method, astronomers measure whether the light from a star dips fractionally as a planet passes between the star and observer.
With gravitational microlensing, experts observe two stars in alignment and use the gravity of the nearer star to magnify the light of the distant one.
