You are here:
International Year of Astronomy - IYA2009
News Archives until 2010
Security & Defense
Missions and more
How do we know that planets exist outside our Solar System?
Even in ancient times, people observed the planets that orbit our Sun. Nowadays we know that there are many trillions of other stars in the Universe. It seems likely that planets orbit many of these stars too. The evidence that extrasolar planets exist was obtained for the first time in the 1990s. However, these planets are small, non-luminous bodies that are light years away – how are we able to prove that they exist?
Send article link to:
Your e-mail address:
Any details you supply are not stored. You will receive no unsolicited e-mails as a result.
Last update: 02/11/2009 10:04:59