Organic Matter and the Moon

absorbed Acad Academy aldehydes Alphonsus amino acids ammonia aromatics Astron biological contamination Chicago cm² contemporary terrestrial cosmic rays cosmobiota cross-section cules deposited terrestrial diffuse dissociated dust early history early lunar Earth effective emission energy ergs cm-2 escape velocity exist fraction Fremlin G. P. Kuiper gas cloud gases gm cm-2 Groth H. C. Urey Hollaender hydrocarbons impact indigenous organisms irradiated Kozyrev layer Lederberg less lifetimes lunar atmosphere lunar magnetic field Lunik II magnetic field strength main sequence mean lethal dose meteoritic meteoritic infall methane microorganisms deposited No/N opaque optical depth organic matter organic molecules panspermia particles photodissociation photodissociation limit photon flux photons planetary possibility private communication probes produced quantum yields radioactivity Research Council Sagan secondary lunar atmosphere shortward solar nebula solar proton solar ultraviolet survival synthesized molecules temperatures tens of meters terrestrial microorganisms terrestrial organisms tion ultraviolet radiation vehicle wavelength Zamenhof