Cometary Glycolaldehyde as a Source of pre-RNA Molecules
Nicolle E B Zellner1, Vanessa P McCaffrey2, Jayden H E Butler1,3
1Department of Physics, Albion College, Albion, Michigan, USA.
Astrobiology
|September 28, 2020
Summary
Comets delivered large amounts of glycolaldehyde (GLA), a sugar precursor, to early Earth. Experiments show GLA survives comet impacts, potentially seeding life
Area of Science:
- Astrobiology
- Organic Chemistry
- Planetary Science
Background:
- Over 200 extraterrestrial molecules identified.
- Glycolaldehyde (GLA), a sugar precursor, detected in interstellar medium and comets.
- Comet 67P/Churyumov-Gerasimenko nucleus shows GLA presence.
Purpose of the Study:
- Investigate GLA survival during cometary impacts.
- Assess comets as delivery vehicles for prebiotic molecules.
- Determine the quantity of GLA delivered to early Earth.
Main Methods:
- Impact experiments simulating cometary collisions.
- Analysis of GLA and GLA-clay mixtures.
- Extrapolation of experimental data to early Solar System conditions.
Main Results:
- GLA and GLA-clay samples survived impacts from 4.5 to 25 GPa.
- Up to 10^23 kg of cometary GLA could have survived delivery.
- Threose, erythrose, glycolic acid, and ethylene glycol also delivered or produced.
Conclusions:
- Comets are significant delivery vehicles for prebiotic molecules.
- Cometary GLA provides starting material for formose and Strecker reactions.
- Comets may have supplied essential molecules for the origin of life.
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