Wet, Carbonaceous Asteroids: Altering
Minerals, Changing Amino Acids
+ Water
Aqueous alteration has
substantially affected
the mineralogy of many
carbonaceous
chondrites.
An unaltered chondrule
http://www.psrd.hawaii.edu/April11/amino_acids.html
Amino Acids
Amino acids are characterized by the
presence of an amine group, NH2, and a
carboxylic acid group, COOH, joined to
side chains (R). Two examples are
shown.
NASA /Mary Pat Hrybyk-Keith
Amino acids also can have
symmetrical differences in their
structures, mirror images of
each other. Shown are Lisovaline and D-isovaline.
http://www.psrd.hawaii.edu/April11/amino_acids.html
Changes in the Amino Acid Mix with
Aqueous Alteration
Modified from Glavin et al., 2011.
Increasing alteration causes the abundance of -Alanine to increase,
others to decrease.
http://www.psrd.hawaii.edu/April11/amino_acids.html
Changes in L/D with Aqueous Alteration
Graphic prepared with data from Glavin et al. (2011).
Aqueous alteration appears to have enriched isovaline in the L
structure, suggesting that this could have happened on the early
Earth or that carbonaceous chondrite asteroids added an already
asymmetrical mix to the Earth.
http://www.psrd.hawaii.edu/April11/amino_acids.html