This artist's view shows an exoplanet orbiting the young star Beta Pictoris. The exoplanet has an eight-hour day — and a much faster rotation than any planet in the solar system.
L. Calçada/N. Risinger/ESO
A visit to Jupiter's moon Europa in the 2020s is among the upcoming NASA missions that have real potential to search for "biosignatures," or substances that provide evidence of life.
Radio telescopes of the Allen Telescope Array are seen in Hat Creek, Calif. A signal that intrigued scientists has been found to have its roots on Earth, Russian scientists say.