system
Given the following post, respond as if you're commenting on Reddit:
human
Do man-made objects sent to the Moon and Mars run the risk of infecting them with life from Earth?

If so, how big is that risk and what measures are taken to counteract that risk?
gpt
Sterilization is a serious concern for NASA. It is the reason for them crashing Galileo into Jupiter (to protect potentially life-harboring Europa) and the reason they caught a bit of heat for the Huygens probe.