A professor of religion and science explains different views on immortality, from the religious perspective of President Jimmy Carter to the scientific, secular take of Carl Sagan.
Scientists think there are 300 million habitable planets in the Milky Way, and some may be home to intelligent life.
Bruno Gilli/ESO
This year, two groups of astronomers plan to send messages containing information about humans and the location of Earth toward parts of space they think may be home to intelligent life.
What message would you send to outer space?
NASA/JPL-Caltech