"We do really have a lot of evidence pointing in the direction of life on Mars," says astrobiologist Dirk Schulze-Makuch. "I think it’s actually more scientifically outrageous to think that Mars is and always has been sterile." He argues that we need another ambitious mission to Mars to find the signs of life he believes are out there. "Mars should be top priority. ... After that there are lots of places, notably the subsurface oceans in Europa, Ganymede, and some of the other moons in the outer solar system. There are even chances in those places for life that could be multicellular, more complex."