There have been reports for over a century of people finding what the Germans call sternenrotz (which literally means "star snot") in conjunction with meteors falling from the sky. It's usually clear or yellowish, smells awful and disintegrates after being handled, much like one of our erections. Despite being described thoroughly in numerous newspaper and police accounts for over 150 years, no one has ever really been able to study it in depth because the substance falls apart too quickly to allow for a sample to be obtained.
Case in point: in 1950, four Philadelphia police men found a six-foot lump of star jelly outside of town. When they tried to pick it up, it dissolved into "odorless, sticky scum." No doubt they all took a shower afterward and couldn't look each other in the eye ever again.
So, What do the Smart People Think is Happening?
Most scientists are more than happy to say witnesses are full of shit and leave it at that, but some at least try to explain it. The glob found by the policemen in Philadelphia was a half mile away from the Philadelphia gas works, so some assert that it was a discharge of some sort (which is simultaneously plausible and just as unlikely as space boogers).
Other theories have included bird vomit, frog spawn vomited up by other animals and generally a bunch of other vomit-related ideas. The goo could also be mundane types of algae slimes that people just happen to notice around the time of a meteor fall. By far the most ball-crushingly awesome theory claims that star jelly is the remains of atmospheric beasts, mythical creatures that some claim float around in the atmosphere. Why we're not constantly scraping such creatures from the windshields of airliners is not explained.