Researchers

Gary Ruvkun , Professor of Genetics, Harvard Medical School
Michael Finney, Former Chief Scientific Officer and Principal, MJ Research
Maria T. Zuber, E.A. Griswold Professor of Geophysics and Planetary Science, MIT
Chris Carr, PhD
George M. Church, Professor of Genetics and Director of the Lipper Center for Computational Genomics, Harvard Medical School
Walter Gilbert, University Professor, Dept. of Molecular and Cellular Biology, Harvard University
Stephen Quake, Associate Professor of Applied Physics, Caltech
William F. Mayer, Associate Director, Center for Space Research, MIT

Brief Summary

Strategies for detecting life on other planets have sought to avoid the assumption it would share any particular features with life on Earth. The most general strategies - seeking informational polymers, structures of biogenic origin, or chemical or isotopic signatures of enzymatic processes - look for features that all life is expected to exhibit. This generality comes at a cost: the strategies are not particularly sensitive, and more importantly, there are abiological routes to these life signatures. However, if life on Earth is actually related to life on other planets, we can use a far more powerful and information-rich technique developed to detect the most extreme forms of life on Earth.

Increasing evidence, such as the low temperature transfer of ALH84001, and theoretical calculations suggest that objects capable of carrying life have been transferred between solar system bodies with significant frequency. In addition, extremophiles have been discovered in Earth environments with high radiation and frozen conditions which, while not as extreme as those on Mars and other planets, demonstrate the incredible adaptability of microbes and suggest that habitable zones are much broader than previously thought. Together these facts raise the possibility that life could have been transferred between Earth and Mars perhaps early in the history of the solar system, and could survive on Mars to the present day. Therefore, we propose to build a very low power and lightweight instrument to test for life on other bodies, most immediately Mars, using the most sensitive known detector for Earthly life.

Life on Mars should resemble life on Earth if there has been exchange of living cells between Mars and Earth. For this to be the case, organisms must have survived the passage, and adapted to a new environment. The ability of a crustal sample to escape Mars and land on Earth without sterilizing heating is demonstrated by the low temperature transfer of ALH84001. Experimental observations of 4 Km/sec test impacts favor this observation: non-shocked and therefore essentially unheated high velocity ejecta occur. It is thought that in any impact, the reflected shock wave interferes with the impact shock wave to allow a region of no shock heating that nevertheless accelerates to escape velocity. Theory also supports this view: for 1 to 20 Km impactors, the low temperature meteoritic exchange between Mars and Earth has been estimated at 10 8 to 10 11 ejecta with an average diameter of 0.3 to 6 meters. Because of cosmic and isotopic decay radiation, transit times are critical. About 3 to 5% of the ejecta from Mars arrive on Earth within 10 million years, but perhaps some in as short as decades. Transfer from Earth to Mars is about 100-fold less efficient, but is still substantial.

Click here for the full summary of our research on life on Mars.