EXOPLANETS!

EXOPLANETS!

EXOPLANETS!

Why Study Exoplanets?

Exoplanets are planets that orbit stars other than our own sun. We are finding that exoplanets are fantastically common; we're finding new planets all the time! We've found over 800 exoplanets since the first exoplanet discovery—some are huge gas giants that are nearly stars themselves, while others are smaller rocky planets with even less mass than Earth. They orbit a diverse range of stars, from red dwarfs to pulsars. The more we learn about exoplanets, the more we learn about how planets can form and interact with each other, and about how our own solar system fits into the rest of the galaxy and the universe. 

The Hubble Space Telescope, in addition to having taken some awesome deep field pictures, has allowed us to study exoplanets in greater detail.  One way this is commonly done is by observing their transits around their stars; that is, we can see when an exoplanet passes between us and its star. Detection of exoplanets by transit is a fairly common method, and can yield a lot of information about the planet, such as its size, mass, and orbital shape. Hubble has also taken pictures of the disks around stars from which planets form, so we can learn more about planet formation by watching it happen*.  In a few rare cases, Hubble has even captured a direct image of the exoplanet itself.  So, Hubble has let us do some pretty cool science! 

*It should be said that the process of planet formation occurs over millions of years, so, you know, we're watching it happen really slowly.