Earth

What does exoscience mean? In its basic sense, it is all the sciences that are used beyond Earth. Exo means "outside."

Exobiology

Is exobiology the study of extraterrestrial life on exoplanets? Also known as astrobiology, these terms mean the study of anything biological in space. Some have adopted the term to mean the exclusive study of aliens, but this is not accurate.
It could someday stretch to include other astro species, but for now it's about studying the effects of space on Earth-based life, whatever organic life we may find, and the evolution of life in the Universe. Just ask astrobiologist Pascale Ehrenfreund. A related field, space psychology, is the study of the effects of space on the brain.

Exoplanets could be anywhere there is a star, but most known exoplanets are currently found our in our local neighborhood.

See the exoplanets page for a few notable examples. Here is a technical catalog, and a user-friendly interactive one. Check out the articles listed under exoresources which include slideshows similar to the exoplanets page format. The exogalleries page has links to visual data and artists' impressions.

Looking for Exoplanets

There are several methods used in discovering exoplanets, but also some hindrances. Optics from Earth are still not often strong enough to see exoplanets in the visual spectrum but rarely. Another issue is that unlike stars which are easy to see because they are luminous, planets only reflect a minimal amount of light. Currently scientists rely on other electromagnetic radiation and indirect evidence such as:

Kepler Space Telescope

In March 2009, NASA launched the Kepler Space Telescope whose sole mission is to look for extrasolar planets.

√ Excellent list of the methods used by different observtories.

If only 1% of stars had a planet, there could be billions of other Earth-like planets.

Although exoplanet research began to gain serious momentum in the 1980s, it wasn't until 1995 that the first exoplanet, 51 Pegasi b, was discovered by Geoffrey Marcy and Paul Butler, along with another team Didier Queloz and Michael Mayor. More on the story. You can see Geoffrey Marcy in The History Channel® documentary The Universe - Season 2.

As of Oct 2011, JPL's PlanetQuest reports 687 exoplanets.

Please see the resources page, or visit JPL's PlanetQuest.