Tags Dr. Gil Levin Viking Labeled Release Life Detection Experiment Viking 1976 landers NASA Leonard David Martian organics methane on Mars methane cycles The Journal of Astrobiology extremophiles newly discover lake on Mars polar ice caps liquid water Europa Enceladus Martian fossil stromatolites kerogens ESA trace gas orbiter planetary protection Dr. Lisa Pratt spacecraft sterilization chiro labeled release life detection experiment Martian rock biology Independent Mars review panel Martian experiment lead time Dr. Patricia Ann Straat Guest Dr. Gilbert Levin Tagline updates with his Viking Mars Lander life searching experiment View the discussion thread.