Perhaps one of the most intriguing and popular issues in today’s science fiction and fantasy genres is the question of whether life exists outside Earth. From movies like “”Contact”” and “”E.T.”” to television shows like “”Star Trek”” and “”Stargate,”” human beings are drawn to the idea that we may not be alone in the universe.
But what was only a concept may now be reality – at least by 2013. Professor Jeffrey Bada, director of the NASA Specialized Center of Research and Training in Exobiology at Scripps Institution of Oceanography, has marked the date as a personal deadline to prove life’s existence on Mars. His main tool will be the Urey Mars Organic and Oxidant Detector, a device designed to sample soil from the surface of Mars and test for life.
The Urey will be traveling aboard the ExoMars Mission, an internationally designed rover carrying a variety of devices to Mars.
Once the Urey collects a sample of crushed rock, it goes into high gear. The device is actually a collection of a few highly specialized instruments. First, its Mars Organic Detector, the principal element of the machine, separates the organic material in the sample from the rock and soil, analyzing the amounts of amino acids, among other organic substances, present in the soil.
If the M.O.D. were to detect any amino acids in the samples, the Microfabricated Capillary Electrophoresis instrument, a device developed at UC Berkeley by Richard Mathies, a professor and member of the California Institute for Quantitative Biomedical Research, begins its work. The CE uses a process similar to gel electrophoresis, a biological technique in which an electrical charge is applied to gel containing samples of genetic material. After analysis, scientists can eventually determine the order of bases in a segment of DNA.
Similar techniques are applied in the MCE, except on a much smaller scale. “”Our contribution is what is known as a lab on a chip,”” Mathies said.
The ultimate goal is to determine the orientation, either “”right-handed”” or “”left-handed,”” of any amino acids discovered, known as chirality. Scientists have noticed that on Earth, amino acids derived from inorganic sources generally have equal proportions of each type of chirality. Organic samples on Earth always have an excess of left-handed amino acids.
Bada and Mathies said they hope to discover an excess of one chirality of amino acids in the samples on Mars, indicating the presence of life.
The Urey also contains a device that will measure the presence of water vapors in the hope of determining if there is still a significant amount of water on or near the surface of Mars.
One of the most novel developments in the Urey, the device will yield results hundreds or thousands of times more sensitive than other similar devices that were used on the 1976 Viking rovers, the only other Mars mission to test for life.
Another important feature is that the rover carrying the Urey can drill up to two meters below the Martian surface, where radiation may not yet have degraded any biochemical compounds that might be present.
This radiation is troublesome in other ways as well. “”That’s the key thing,”” Mathies said. “”We have to develop systems that are robust enough and basically self-contained so that we can fly them to Mars and do the experiments on Mars.””
He explained that the team is optimistic. A year and a half ago, the development team flew down to the Atacama desert in Chile, an inland valley next to the Andes, to test a prototype design in the harsh climate. They ran the device for almost two weeks without any incident.
The Urey is scheduled to leave Earth in 2013, probably during the late fall or early winter. Although the date seems far off, Bada said that there is a lot of work to do to prepare.
“”There is a long history here,”” Bada said. “”I have been part of a group here at UCSD and the Salk Institute and the Scripps Research Institute trying to figure out the processes that led to life on Earth. This has been a long-term project funded by NASA.””
The project began 15 years ago when Bada hosted a talk at the California Institute of Technology. A representative from NASA’s Jet Propulsion Laboratory in Pasadena, Calif. who happened to be there took an interest in Bada’s findings. That began a long-term collaboration. Richard Mathies joined the team about five years later. Bada explained the team named the instrument after Harold Urey because of his contributions to chemistry and UCSD.
“”We put together this proposal, which was reviewed by NASA,”” Bada said. “”Prior to that we had already submitted this instrument as a candidate instrument for the European Space Agency’s ExoMars mission.””
They accepted that instrument design, but the team wanted NASA’s support as well. Bada’s team submitted a grant proposal on Aug. 1 of last year and received approval on Jan. 8, 2007 for an amount of $750,000 from NASA.
“”The one thing I’ve learned about this is that you have to be very, very patient,”” Bada said.
Now that funding has been approved, however, work is beginning at a faster pace. In addition to their weekly teleconferences, Bada explained that team members will begin meeting face-to-face on a regular basis.
And if they should discover evidence of past or present life on Mars?
“”Any discovery of extraterrestrial life would fundamentally change our understanding of our existence in the universe,”” Mathies said.
He sees it as the fourth major step in understanding the universe. Humans realized that the Earth was not flat, they realized that it was not the center of the universe and then they began examining the genetic code, the molecular basis of existence. He believes that the next step will be to realize that humans are not alone in the universe.
“”If we found evidence of life it would just change our whole knowledge base about life and how ubiquitous it is,”” Bada said. He believes that if we find life on two planets within the same solar system, life must be everywhere in the universe.
Of course, discovery of an alien life form would raise a lot of other questions: How similar is this life to terrestrial life? Are these organisms related? Are they compatible with Earth’s organisms?
However, there will be plenty of time for those speculations once the team gets definitive results from the Urey. Until then, Bada said. “”This is a once in a lifetime opportunity and I just feel very fortunate to be involved in it.””
