LExEN, an acronym for Life in Extreme Environments, is a research program overseen by the National Science Foundation.
[1] It was originally developed by G. Michael Purdy in 1997 as an area of research in which scientists could seek funding for activities in the polar regions.
[2] The program sought to place a strong emphasis upon those life-supporting environments that exist near the extremes of planetary conditions.
The study of extreme habitats, both planetary and extra-planetary, was underpinned by the idea that "deep understanding of certain earth-bound microbial systems would provide important insights into life-sustaining processes and the origin of life on our own planet, while illuminating the search for life in other planetary environments.
"[3] In 1999 it was announced that the future of LExEN was still under consideration[4] but despite the lack of research in the topic, the program no longer appears on the NSF A-Z Index of Funding Opportunities.