Responsible Official:
Dr. Joseph H. King, Code 633

Last Revised: [link updated, 9 March 2006, DRW]

Signs of Martian Life at NSSDC

A recent New York Times feature article announced, “Data collected 25 years ago on Mars by NASA’s two Viking Landers show evidence of life, a scientist contends.” The article described the discovery of a circadian rhythm in data returned from the Labeled Release Experiments (Principal Investigator: Dr. Gil Levin) on the Viking Landers, a rhythm which was interpreted as an indication of extant microbial life in the samples scooped up from the Martian surface.

Much of the data on which this study was based came from microfilm archived here at NSSDC since the late 1970s. The recent interest has resulted in an effort by NSSDC and the Planetary Data System to digitize the microfilm as well as paper listings still held by the original Co-Investigator, Dr. Pat Straat, as described in an earlier Newsletter article at

An early portion of the digitized data was used by a scientist on the data set review panel to come up with these remarkable, albeit still very controversial, findings. The data are now almost fully digitized and validated. A preliminary version was posted in mid-August 2001 at

Over the next few months more data will be added to this collection. It is expected the later data set data will be used for detailed analyses in the near future to verify the claims of evidence for life on Mars in the preliminary data. end of paragraph mark