Table 1 UV irradiation experiments of organics at the most relevant wavelengths.

Ref.	Organic	Photons (nm)	Location	Temp.	Half life at 1 AU	Half life at 9.5 AU (yrs)^a	Notes
⁵⁹	Glycine	Solar >115 nm	Earth Orbit	232 to 289 K	3.7-7.0	0.9–1.7	No ice and with warm temps (and some loss observed in dark controls)
	Aspartic				1.0-2.2	0.3–0.6
	Glutamic				1.1-1.4	0.3
	Tyrosine				3.0-7.0	0.7–1.7
²²	Glycine	130-300/330	Laboratory	100 K	181-235	45−60	Europa thick ice sim.
	Aspartic				77-84	19–21
	Glutamic				84-92	21–23
	Phenylalanine				61-29^b	15-8^b	Converts to tyrosine^c
³⁰	Glycine	Solar >115 nm	Earth Orbit	251 to 303 K	8	2	No ice and with warm temps
	Adenine				>41	>10
	Guanine				>41	>10
	Xanthine				16	4.0
	Hypoxanthine				>41	>10
	Urea				>41	>10
	PolyC₃O₂				6	1.5
	PolyHCN				10.0	2.5
¹⁵	Glycine	147, 206, 254	Laboratory	18 K	38	9.4	Europa sim. using Ar-ice
¹⁵	Phenylalanine	147, 206, 254	Laboratory	18 K	13.8	3.4	Converts to tyrosine^c
²¹	Glycine	200-450	Laboratory	Up to 313 K	115−129	28-32	No ice and with warm temps
	Alanine				92-115	23-28
	2-Aminoisobutyric				112-330	28-82
	2-Aminobutyric				70-78	17-19
	Valine				70-74	17-18
	Aspartic				29-68	7.2-17
	Dileucine				<15	<3.7
	Glycine	Solar >115 nm	Earth Orbit	Up to 313 K	178-390	44-96
	Alanine				97-261	24-64
	2-Aminoisobutyric				115-285	28-71
	2-Aminobutyric				97-285	24-71
	Valine				97-390	24-96
	Aspartic				27-97	7-24
	Dileucine				<15	<3.7

^aFor studies not at 1 AU, results were extrapolated to 1 AU and then to 9.5 AU. Half-lives for 9.5 AU taken to be 90.25 times 1 AU half-lives. For⁵⁹, low and high half-lives calculated assuming first order kinetics from concentrations remaining ± one standard error of each light and dark experiment added in quadrature. For²², lower half-lives were calculated using the thinnest ice experiments reported in their Table 2 and the higher half-lives use timescales for 50% decomposition penetrating to 1 m depth at Europa (reported in their Table 3), converted to 1 AU. In ref. ¹⁵, the half-lives reported for each wavelength were combined into one decay.
^bIn ref. ²², the phenylalanine half lives using the thinnest ices shows a longer timescale than the modeled result reported in their Table 3.
^cSee Ref. ²⁹.

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