"Brown organic tarry gunk" in the Outer Solar System

(organic = based on carbon)
(more properly, Polycyclic Aromatic Hydrocarbons [PAHs])


Found in:

- Carbonaceous asteroids
- Planetary atmospheres (Jupiter and Saturn: brown, yellow, red clouds)
- Planetary rings (of Uranus and Neptune; 
Jupiter's are dust, Saturn's are ice)
- Satellite atmospheres: 
-	Titan   (large satellite of Saturn)
-	Triton (large satellite of Neptune)
- Dark nebulae, the sites of star formation


Also (not previously covered):

- COMET nuclei:
	the nucleus of Halley's Comet is black.

Comets are "dirty snowballs,"  
different from asteroids only in that they're much icier,
since they're from the outer Solar System.

Did comets deliver ocean water to early Earth?  Still unknown.

And:

- Comet Shoemaker-Levy 9 collided with Jupiter in 1994,
and made Earth-sized clouds of organic compound in Jupiter's atmosphere!