Andrew Steele uses traditional and biotechnological approaches for the detection of microbial life in the field of astrobiology and Solar System exploration. Astrobiology is the search for the origin and distribution of life in the universe. A microbiologist by training, his principle interest is in developing protocols, instrumentation, and procedures for life detection in samples from the early Earth and elsewhere in the Solar System.
Steele has developed several instrument and mission concepts for future Mars missions and became involved in the 2011 Mars Science Laboratory mission as a member of the Sample Analysis at Mars (SAM) team. For a number of years he journeyed to the arctic every summer to test instruments on board the Arctic Mars Analogue Svalbard Expedition (AMASE).
As an active member of the NASA Astrobiology Institute, Steele works with a technique called high-resolution confocal Raman imaging. His work has led to exciting work in planetary science including the NASA Stardust sample return mission, the discovery of new forms of carbon in meteorites and Lunar rocks, and the discovery of a previously uncharacterized mechanisms of organic synthesis in the absence of living organisms within the Earth’s mantle and on Mars.
Steele also studies meteorites. Molecules containing large chains of carbon and hydrogen—the building blocks of life—have been the tantalizing targets of many Mars missions. Theories about the origin of the large chains of carbon and hydrogen macromolecules in Martian meteorites are particularly interesting. They could come from contamination from Earth or other meteorites, chemical reactions on Mars, or remnants of ancient Martian life. Steele and team have been studying meteorites to determine the sources and processing of this carbon.
Using sophisticated techniques, his team showed that some of the carbon was from meteorites and not from contamination, but that the carbon was not biological in origin. They then looked at the carbon molecules in relation to other minerals to understand the chemical processing. They found that the carbon was created during volcanism on Mars, showing that the planet has undergone organic chemistry for most of its history.
Recently Steele’s team helped colleagues study a new class of Martian meteorite that likely originated from the Martian crust. The meteorite, NWA 7034, has an order of magnitude of more water than any other Martian meteorite and its texture is different. It has cemented fragments of basalt, which forms from rapidly cooled lava, with feldspar and pyroxene, most likely from volcanism. This composition is common for lunar samples but not for other Martian meteorites. Steele and his team studied organic carbon within the feldspar. Although the carbon is similar to other Martian meteorites, a different non-biological process was at work.
Steele received his B. Sc. in biochemistry and microbiology from the University of Central Lancashire and his Ph. D. from the Universtiy of Portsmouth. Before joining Carnegie he was a postdoctoral fellow at NASA Johnson Space Center and he was a researcher at Oxford University, a lecturer at the University of Portsmouth and an assistant professor at Montana State University. For more see https://www.gl.ciw.edu/bios/asteele