  Very little experimental work has been done to explore the properties of
photochemical hazes formed in atmospheres with very different compositions or
temperatures than that of the outer solar system or of early Earth. With
extrasolar planet discoveries now numbering thousands, this untapped phase
space merits exploration. This study presents measured chemical properties of
haze particles produced in laboratory analogues of exoplanet atmospheres. We
used very high resolution mass spectrometry to measure the chemical components
of solid particles produced in atmospheric chamber experiments. Many complex
molecular species with general chemical formulas C$_w$H$_x$N$_y$O$_z$ were
detected. We detect molecular formulas of prebiotic interest in the data,
including those for the monosaccharide glyceraldehyde, a variety of amino acids
and nucleotide bases, and several sugar derivatives. Additionally, the
experimental exoplanetary haze analogues exhibit diverse solubility
characteristics, which provide insight into the possibility of further chemical
or physical alteration of photochemical hazes in super-Earth and mini-Neptune
atmospheres. These exoplanet analogue particles can help us better understand
chemical atmospheric processes and suggest a possible source of in situ
atmospheric prebiotic chemistry on distant worlds.
