With the recent discoveries of hundreds of planets outside our solar system, astronomers have begun thinking about life light-years from our sun. But alien life might reside much closer to home. Did Mars once harbor life—and might it still? Is something swimming in the ice-encased ocean of Jupiter's moon, Europa? And with mounting evidence for liquid water on Saturn's moon, Enceladus, might scientists have their best shot yet of spotting life beyond Earth?
Join us for a live chat with experts on these topics at 3 p.m. EDT on 9 June on this page. You can leave your questions in the comment box below before the chat starts.
Chris McKay is an astrobiologist with NASA. His current research focuses on the evolution of the solar system and the origin of life. He is also actively involved in planning for future Mars missions including human settlements.
Andrew Steele uses traditional and biotechnological approaches for the detection of microbial life in astrobiology and solar system exploration. A microbiologist by training and an astrobiologist by choice, his principle interest is in developing protocols, instrumentation and procedures for life detection in samples from the early earth and elsewhere in the solar system.