Bacteria could survive travel between Earth and Mars when forming aggregates:
Dr. Yamagishi and the Tanpopo ["Dandelion"] team, tested the survival of the radioresistant bacteria Deinococcus in space. The study, now published in Frontiers in Microbiology, shows that thick aggregates can provide sufficient protection for the survival of bacteria during several years in the harsh space environment.
Dr. Yamagishi and his team came to this conclusion by placing dried Deinococcus aggregates in exposure panels outside of the International Space Station (ISS). The samples of different thicknesses were exposed to space environment for one, two, or three years and then tested for their survival.
After three years, the researchers found that all aggregates superior to 0.5 mm partially survived to space conditions. Observations suggest that while the bacteria at the surface of the aggregate died, it created a protective layer for the bacteria beneath ensuring the survival of the colony. Using the survival data at one, two, and three years of exposure, the researchers estimated that a pellet thicker than 0.5 mm would have survived between 15 and 45 years on the ISS. The design of the experiment allowed the researcher to extrapolate and predict that a colony of 1 mm of diameter could potentially survive up to 8 years in outer space conditions.
The survival time is thought to be sufficient for bacteria to travel between Mars and Earth.
Journal Reference:
Yuko Kawaguchi et al, DNA Damage and Survival Time Course of Deinococcal Cell Pellets During 3 Years of Exposure to Outer Space, Frontiers in Microbiology (2020). DOI: 10.3389/fmicb.2020.02050
(Score: 2) by requerdanos on Thursday August 27 2020, @02:49PM (2 children)
A half millimeter pellet is big enough to live 45 years, but a 1mm pellet is only big enough to live 8 years.
There must be some information missing here, because those proportions aren't making sense to me. I would think the 1mm pellet would live at least as long as the 0.5mm one.
(Score: 2) by Freeman on Thursday August 27 2020, @03:03PM (1 child)
I'm guessing the missing connection is on the ISS vs hard vaccuum of space. Not sure why it would matter much how long it could survive on the ISS. They could have worded the article a bit better.
Joshua 1:9 "Be strong and of a good courage; be not afraid, neither be thou dismayed: for the Lord thy God is with thee"
(Score: 2) by requerdanos on Thursday August 27 2020, @03:19PM
That makes sense, but the article seems to equate "outside the ISS" with "the harsh space environment." From the article:
I suspect that, like you say, it's down to wording.