Ward presents his new model in a book called "Life As We Do Not Know It: The NASA Search for (and Synthesis of) Alien Life," published by Viking and being released Thursday. The new system is already necessary, he said, because "alien" life has been created in laboratories on Earth. That includes microbes with at least one amino acid beyond the 20 in the DNA of native Earth life, or organisms that have been genetically modified, Ward said. It also includes some life forms that have been modified to be much simpler than what is normally found on Earth.
"We may never find other life away from Earth, but we have already made aliens on this planet and we will continue to do so at an increasing pace," he said. "In the last five years we've come to realize that we can make microbial life in a lot more ways than Mother Earth did."
Ward believes that if life is found away from Earth, at least some could be based on elements such as silicon, perhaps in combination with carbon. Because environments are far colder on moons and planets farther from the sun, he said, it is less likely that life on the moons of Saturn and Jupiter, for instance, will use water as Earth life does. Instead, those organisms are more likely to use compounds such as ammonia that remain liquid at very low temperatures.
Ward is one of several faculty members in the UW's groundbreaking graduate program in astrobiology. The program, the first of its kind, started in 1998 with a grant from the National Science Foundation and has since been bolstered by funding from the National Aeronautics and Space Administration. Students work in a variety of areas, such as astronomy, microbiology and oceanography, to prepare themselves for the search for life away from Earth.
Ward also was a co-author, with UW astronomer Donald Brownlee, of a popular book called "Rare Earth," published in 2000. The book advanced the idea that simple microbial life might be very common
Source:University of Washington