Astronomer Jill Tarter, Director of the Search for Extraterrestrial Intelligence Institute, discusses Frank Drake's famous attempt to evaluate the likelihood of extraterrestrial life.

In 2013, astronomers reported that they'd found what was, at the time, the biggest thing in the known universe.

(NOTE: This talk was given in 2010, and this field of science has developed quickly since then. Read "Criticisms & updates" below for more details.) Astronomer Dimitar Sasselov and his colleagues search for Earth-like planets that may,...

A new statistical study of planets found by a technique called gravitational microlensing suggests that Neptune-mass worlds are likely the most common type of planet to form in the icy outer realms of planetary...