Today marks the fiftieth anniversary since Frank Drake first fired up Project Ozma on April 8, 1960 and transformed the philosophical question concerning the possibility of sentient beings beyond the Earth into a bona fide empirical scientific pursuit.
The search goes on and as yet we have not detected any signal. But, it’s a very big Cosmos and we have only scanned a few thousand stars in our own Milky Way Galaxy. Since the announcement of the first definitive detection of an exoplanet orbiting the star 51 Pegasi by Michel Mayor and Didier Queloz of the University of Geneva on October 6, 1995 we have discovered 443 extrasolar planets. Planets are plentiful yet, the question remains do they represent a plethora of abodes for life and consciousness in the Cosmos.
The vast majority of the worlds discovered thus far have proven to be the dismal prospects. Most are giant planets thought to resemble Jupiter; however, substantial sampling bias exists since more massive planets are much easier to detect with current technology. A few relatively lightweight exoplanets, only a few times more massive than Earth, have now been detected and projections suggest that planets of roughly Earth-like mass will eventually be found to outnumber extrasolar gas giants. Currently, based on scant evidence, we have placed our hopes on Gliese 581 d, the fourth planet of the red dwarf star Gliese 581 (approximately 20 light years from Earth). It appears to be the best example yet discovered of a possible terrestrial exoplanet that orbits within the habitable zone surrounding its star.
The prospects may vastly improve when the Kepler space telescope completes its survey and with the next generation space based advanced astronomical observatories such as NASA’s Terrestrial Planet Finder, the James Webb Space Telescope and their successors. These telescopes in tandem with the various proposals for the New Worlds Missions will help us image the surfaces of any terrestrial planets that the Kepler space telescope happens to find.
And, for the moment we must rely on the very best our current level of technology has to offer us in the search for extraterrestrial civilizations – The Allen Radio Telescope Array and Optical SETI (OSETI) – the search for powerful lasers pulses used for interstellar communications.
In the meantime we can only speculate as to the nature of creatures that may live on the most promising worlds we may very well discover in years to come. So join us today on Discovery Enterprise aboard the starship SS Attenborough and uncover the natural history of the aliens that we may one day discovery on these brave new abodes of life and sentience.
Natural History of an Alien