Three body reactions do not play a significant role in gas-phase interstellar chemistry
H- + H -> H + e (R~10^{-21} cm^{-3} s^{-1})
Bergin et al. 2004: behind large scale flows, the timescale for H2 formation is ~10 Myr
If T = 100 -> k_bT~0.01 eV
If T = 100 -> k_bT~0.01 eV
ION - MOLECULE REACTION
Most are from undifferentiated parent bodies: original build-up particles still recognizable:
Chondrules (mm size spherules)
Matrix (`cement’ between chondrules: <10 m particles)
Calcium-Aluminium-rich Inclusions (CAIs, cm size, rare)
Point out that we do not know how these molecules are formed. Still unexplored chemistry!
Most amino acids can exist in either of two optical isomers. While L-amino acids represent the vast majority of amino acids found in proteins, D-amino acids are found in some proteins produced by exotic sea-dwelling organisms, such as cone snails.[21]
The left hand is a non-superimposable mirror image of the right hand; no matter how the two hands are oriented, it is impossible for all the major features of both hands to coincide.