Thursday, April 10, 2008

New Planet Detector should find ExoEarths

Astrobiology takes a look at new technology which should greatly aid our search for extraterrestrial earth type planets. The most successful method of finding such worlds has been the "wobble" method, where astronomers observe the gravitational 'tug' of planets of the light we receive from distant stars. In addition, there is even more difficult to detect 'transit' technique whereby the impact of a planet passing in front of the star from our vantage point lowers the amount of light reaching us from the star - obviously, timing is everything for this technique. With either method, large planets in relatively close orbits ('Hot Jupiters') are the easiest to find. Observing these large planets often lead to the discovery of others within the same system after further analysis of the gravitational effects.

However, things, as they say, they are a changin'. We are on what is likely to be the cusp of the greatest explosion of extrasolar planet finds in human history. Around 300 planets have already been detected using current methods.

" A revolutionary laser technology being developed by scientists and engineers at the Harvard-Smithsonian Center for Astrophysics (CfA), with colleagues at MIT, will enable scientists to spot Earth-sized worlds in Earth-like orbits. The technology is a major step forward in the search for habitable worlds beyond our Solar System."We are at the cusp of a new era in planet searches, said CfA astrophysicist Chih-Hao Li. "With this technology we are developing, astronomers will finally be able to find the first truly Earth-like worlds in terms of size and orbit."

The new technology is a highly precise refinement of the 'wobble' technique. Current tech can find planets as small as 5 earth masses, but only in a fairly tight orbit around an alien star. The new device, which the researchers refer to as an 'astro-comb' uses ultrashort duration laser pulses combined with an atomic clock to provide a precision instrument capable of taking accurate measurments as small as one part in a trillion. This refinement may increase the 'wobble' detection accuracy as much aa 100 times, allowing planets even smaller than Earth to be detected. The new device is expected to go live for testing at Mount Hopkins Observatory this summer, with an improved design expected to be installed in the Canary Island's New Earth Facility by 2010.

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