NASA

[nesabelle]

What is the importance of NASA finding a planet circling around the star Fomalhaut? On November 13, 2008, NASA announced that the Hubble Space Telescope has taken a snapshot of a planet circling the star Fomalhaut. Obviously, this is the first planet other than our own that we know of orbits a base star. Other than this, why was this such a significant discovery?

[D_Archer]

The significance was that is was the first time a planet was seen with visible light directly. Usually planets are discovered indirectly using different methods. The two best known are: 1) when a planet crosses the stars and blocks its light towards us it dims the star, scientists then infer that a planet is there (this is called the transit method), 2) a planet causes its star to 'wobble' when it orbits around it (this is called astrometry).

Known extrasolar planets*:
http://exoplanet.eu/catalog.php

Kind regards,
Daniel

*EU note: most planets are still discovered indirectly, it could be that some methods used to observe are faulty (Pulsar timing? Doppler spectroscopy? Gravitational microlensing? all debatable detection methods.