lecture11 - 1 Extraterrestrial Life: Spring 2008 Limits of...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 1 Extraterrestrial Life: Spring 2008 Limits of life on Earth Some archaea and bacteria ( extremophiles ) can live in environments that we would consider inhospitable to life (heat, cold, acidity, high pressure etc) Distinguish between growth and survival: many organisms can survive intervals of harsh conditions but could not live permanently in such conditions (e.g. seeds, spores) Interest: analogs for extraterrestrial environments `extreme conditions may have been more common on the early Earth - origin of life? some unusual environments (e.g. subterranean) are very widespread Extraterrestrial Life: Spring 2008 Thermophiles Temperatures up to ~55C are common, but T > 55C is associated usually with geothermal features (hot springs, volcanic activity etc) Thermophiles are organisms that can successfully live at high temperatures Best studied extremophiles: may be relevant to the origin of life. Very hot environments tolerable for life do not seem to exist elsewhere in the Solar System Extraterrestrial Life: Spring 2008 Grand Prismatic Spring, Yellowstone National Park Colors on the edge of the spring are caused by different colonies of thermophilic cyanobacteria and algae ~50 species of such thermophiles - mostly archae with some cyanobacteria and anaerobic photosynthetic bacteria Sulfolobus : optimum T ~ 80C, minimum 60C, maximum 90C, also prefer a moderately acidic pH. Live by oxidizing sulfuralso prefer a moderately acidic pH....
View Full Document

Page1 / 3

lecture11 - 1 Extraterrestrial Life: Spring 2008 Limits of...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online