Unseen planet revealed by its gravity
Thursday, May 10, 2012 - 22:30
in Astronomy & Space
More than a 150 years ago, before Neptune was ever sighted in the night sky, French mathematician Urbain Le Verrier predicted the planet's existence based on small deviations in the motion of Uranus. Scientists have now inferred another unseen planet, this time orbiting a distant star, marking the first success of this technique outside the solar system.