Title: Did Life Come from Mars?

Abstract:

The origin of life remains one of the great unsolved problems of science. The search for life on Mars has led to increasing speculation that life may have started there and come to Earth later in rocks ejected from the Red Planet by comet impacts. Mars offers a more favorable planet than Earth for life to get started for a number of reasons. But would any organism survive the violence of ejection and the hostile environment of space? And what implications would cross-planetary inoculation have for our attempts to answer the biggest question of all: are we alone in the universe?