Hubble celebrated its 18th anniversary in 2008 by releasing a huge image gallery of interacting galaxies. Such galaxies pass close enough to each other that their mutual gravity can stretch and distort their shapes. Eventually, interacting galaxies merge together to form a single larger galaxy. However, since these interactions can take billions of years, how do we study them?
“Hubble’s Universe” is a recurring broadcast from HubbleSite, online home of the Hubble Space Telescope. Astrophysicist Frank Summers takes viewers on an in-depth tour of the latest Hubble discoveries. Find more episodes at HubbleSite.org.