NEW SEARCH FOR ALIEN LIFE
For thousands of years humans have speculated that the cosmos is teeming with planets, many of which could support life. Our questioning has tapped into a long-held desire to know our place in the universe – a core human yearning which has preoccupied some of history’s greatest minds. But speculation is about as far as humans got until we invented telescopes and developed a proper understanding of the scientific method a few centuries ago. Now scientists are making considerable progress in the search for alien life, and the past decade has proven pivotal. Some big discoveries may be coming soon, but where has the hunt for life taken us, and where is it heading?
One of the first modern searches for life took place in August 1924, when astronomer David Peck Todd and an inventor called Charles Jenkins wanted to listen for messages from Mars. They asked the US Army and Navy to turn off their stations so they could use their radio-photo message machine to carry out a search. Alas, they drew a blank. In 1960, however, the search for extraterrestrial intelligence (SETI) intensified when Cornell University astronomer Frank Drake used a radio telescope in West Virginia to listen for interstellar radio waves coming from the stars Tau Ceti and Epsilon Eridani. Called Project Ozma, this effort incorporated ideas from a seminal 1959 paper by Giuseppe Cocconi and Philip Morrison. But again it detected no recognisable signals.
Undeterred, scientists have been scanning the heavens for technosignatures ever since. Initially they focused almost exclusively on radio signals, but flashes of light are now being sought too. These are the targets of increasingly common ‘optical SETI’ efforts. But then SETI scientists have to keep an open mind. After all, we don’t know what sorts of messages advanced alien civilisations might
