Microbial habitability of the Hadean Earth during the late heavy bombardment

Physics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

19

Scientific paper

Lunar rocks and impact melts, lunar and asteroidal meteorites, and an ancient martian meteorite record thermal metamorphic events with ages that group around and/or do not exceed 3.9Gyr. That such a diverse suite of solar system materials share this feature is interpreted to be the result of a post-primary-accretion cataclysmic spike in the number of impacts commonly referred to as the late heavy bombardment (LHB). Despite its obvious significance to the preservation of crust and the survivability of an emergent biosphere, the thermal effects of this bombardment on the young Earth remain poorly constrained. Here we report numerical models constructed to probe the degree of thermal metamorphism in the crust in the effort to recreate the effect of the LHB on the Earth as a whole; outputs were used to assess habitable volumes of crust for a possible near-surface and subsurface primordial microbial biosphere. Our analysis shows that there is no plausible situation in which the habitable zone was fully sterilized on Earth, at least since the termination of primary accretion of the planets and the postulated impact origin of the Moon. Our results explain the root location of hyperthermophilic bacteria in the phylogenetic tree for 16S small-subunit ribosomal RNA, and bode well for the persistence of microbial biospheres even on planetary bodies strongly reworked by impacts.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Microbial habitability of the Hadean Earth during the late heavy bombardment does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Microbial habitability of the Hadean Earth during the late heavy bombardment, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Microbial habitability of the Hadean Earth during the late heavy bombardment will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1110034

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.