 Interplanetary transfer of nonliving material is well documented, as evidenced by meteorites of Martian origin found on Earth.Space probes may also be a viable transport mechanism for interplanetary cross-pollination in the Solar System or even beyond.However, space agencies have implemented planetary protection procedures to reduce the risk of planetary contamination, although, as recently discovered, some microorganisms, such as Tersicoccus phoenicis, may be resistant to procedures used in spacecraft assembly clean room facilities.