The many recent discoveries about the past and present habitability of Mars are linked to an astrobiology-inspired strategy for Mars exploration called “follow the water.” The NAI played a key role in recommendations for landing sites for the Mars Exploration Rovers (MERs), which were presented by the focus group chair (Jack Farmer, principal investigator [PI] of the NAI team at Arizona State University) at community-wide landing-site workshops. Based on inputs from these workshops, the MER Landing Sites Steering Committee developed a short list of approximately 10 sites, half of them on the NAI list of recommendations. Both of the final landing site selections (Opportunity’s landing site on Meridiani Planum and Spirit’s landing site in Gusev Crater) had been given a high priority for astrobiology by the NAI Mars Focus Group. On the question of landing site selection, interactions between the NAI and NASA’s Mars Exploration Program Analysis Group (MEPAG) were promoted through several NAI-sponsored videoconferences organized by the chair of the Mars Focus Group. So effective were these contributions that when Jack Farmer was appointed to lead MEPAG, much of the NAI focus group activity simply merged with the NASA-wide advisory system.

Another indication of NAI influence can be drawn from the fact that roughly 70 percent of the authors of recent MEPAG reports are members of past or present NAI teams. These individuals include the following:

• Ames Research Center team—David Des Marais (PI), Christopher McKay, and Allan Treiman;

• Arizona State University team—Phillip Christensen, James Elser, Jack Farmer (PI), Ronald Greeley, and Ferran Garcia-Pichel;

• Carnegie Institution of Washington team—Nora Noffke and Andrew Steele;

• Goddard Space Flight Center team—Paul Mahaffy;

• Jet Propulsion Laboratory team—Kenneth Nealson (PI);

• Johnson Space Center team—Thomas Kieft;

• Marine Biological Laboratory team—James Head and Mitchell Sogin (PI);

• Massachusetts Institute of Technology team—Roger Summons (PI);

• Pennsylvania State University team—Christopher House;

• SETI Institute team—Rocco Mancinelli (PI);

• University of Arizona team—John Baross;

• University of Colorado team—Bruce Jakosky (PI) and Stephen Mojzsis;

• University of Hawaii team—Jeffrey Taylor; and

• University of Washington team—John Baross and Jody Deming.