Microorganisms of the permafrost, glaciers, and polar ice sheets of planet Earth provide analogs for microbial life forms that may be encountered on ice or permafrost of Mars, Europa, Callisto, Ganymede, or even asteroids or comets. Most bodies of our Solar System are frozen worlds. The microbiota of the terrestrial cryosphere help establish the thermal and temporal limitations of life on Earth and provide clues to of where and how we should search for evidence of life elsewhere in the Cosmos. Consequently, these life forms are relevant to Astrobiology. Cryopreserved microorganisms can remain viable (in deep anabiosis) in permafrost and ice for millions of years and may contain intact ancient DNA, lipids, enzymes, proteins and genes. Some microorganisms carry out metabolic processes in water films and brine, acidic, or alkaline channels in permafrost or ice at temperature far below 0 C. Complex microbial ecosystems may inhabit snow, ice-bubbles, and cryoconite holes on glaciers and the polar caps. At the NASA Marshall Space Flight Center we employed the Environmental Scanning Electron Microscope to study the morphology, ultra- microstructure and chemical composition of microorganisms in-situ in ancient permafrost and ice. In this paper we present images of cryopreserved microorganisms from deep ice cores above Lake Vostok and thermokarst ponds of the Fox Tunnel of Alaska.

Date Published: 30 December 1999
PDF: 13 pages
Proc. SPIE 3755, Instruments, Methods, and Missions for Astrobiology II, (30 December 1999); doi: 10.1117/12.375087

Published in SPIE Proceedings Vol. 3755:
Instruments, Methods, and Missions for Astrobiology II
Richard B. Hoover, Editor(s)