Dave Summers investigates a wide range of chemical reactions that are either needed for life to begin, that may affect whether life can exist, or that might be used by scientists to recognize life elsewhere. For example he is looking at the reactions of nitrogen in the atmosphere of ancient Mars. Where did it go? Could it have provided nitrogen for the start of life on Mars?
It may be that vesicles, water filled “soap bubbles” that look something like cells, may have been important in the origin of life. Dave is looking at what reactions may occur inside these vesicles, and how they may related to things like the start of photosynthesis.
Life shows a preference for using the lighter isotope of carbon – carbon-12 – rather than the slightly heavier carbon-13 when it makes stuff out of carbon dioxide. Can we use this as a test for whether compounds were made by life? Or might inorganic reactions do the same thing? Dave is doing the hard work of examining how this same preference for lighter carbon might also be exhibited by completely inorganic reactions. By understanding how this can happen, he may keep future space missions from stumbling over a false claim of extraterrestrial biology. He is also interested in how we can test for such compounds as proteins or fatty acids to detect life, both in the lab and robotic missions. Dave doesn’t just assume we’ll just “know life when we see it.” He wants a better test than that.
- SETI Institute