- On November 11, 1846, a luminous object estimated at 4 feet in diameter fell atLowville, New York, leaving behind a heap of foul-smelling luminous jelly that disappeared quickly, according to Scientific American
- In 1950, four Philadelphia, Pennsylvania policemen reported the discovery of "a domed disk of quivering jelly, 6 feet in diameter, one foot thick at the center and an inch or two near the edge." When they tried to pick it up, it dissolved into an "odorless, sticky scum." This incident inspired the movie The Blob.
- On August 11, 1979, Mrs. Sybil Christian of Frisco, Texas reported the discovery of several purple blobs of goo on her front yard following a Perseid meteor shower. A follow up investigation by reporters and an assistant director of the Fort Worth Museum of Science and History discovered a battery reprocessing plant outside of town where caustic soda was used to clean impurities from the lead in the batteries, resulting in a purplish compound as a byproduct. The report was greeted with some scepticism, however, as the compounds at the reprocessing plant were solid, whereas the blobs on Mrs. Christian's lawn were gelatinous. Others, however, have pointed out that Mrs. Christian had tried to clear them off her lawn with a garden hose.
- In December, 1983, grayish-white, oily gelatin fell on North Reading,Massachusetts. Thomas Grinley reported finding it on his lawn, on the streets and sidewalks, and dripping from gas station pumps.
- On several dates in 1994, "gelatinous rain" fell on Oakville, Washington. The story was featured in a 1995 episode of Unsolved Mysteries. A National Geographic video called "Mystery Goo Rain" advances a conspiracy theory using an interview with microbiologist Mike McDowell, who says he tested the substance and speculated that it was "a matrix" containing Pseudomonas fluorescens and Enterobacter cloacae that could cause illness to those who touched it. In the video, McDowell claims that "the sample went missing" and when he asked the management what happened to it, he was told "Do not ask", leading him to believe "this material was manufactured by someone for some purpose" and that the town "was chosen as a test site".
- In 1997, a similar substance fell in the Everett, Washington area.
- On the evening of November 3, 1996, a meteor was reported flashing across the sky of Kempton, Australia, just outside of Hobart. The next morning, white translucent slime was reportedly discovered on the lawns and sidewalks of the town.
- Star jelly was found on various Scottish hills in the autumn of 2009.
- Star jelly was found on the fells around Ullswater in the Lake District in October 2011.
- Blue balls of jelly rained down on a man's garden in Dorset in January 2012. Upon further analysis these proved to be sodium polyacrylate granules, a kind of superabsorbent polymer with a variety of common (including agricultural) uses. They were most likely already present on the ground in their dehydrated state, and had gone un-noticed until they soaked up water from the hail shower and consequently grew in size.
- Several deposits were discovered at the Ham Wall nature reserve in England in February 2013. It has been suggested that these are unfertilised frog spawn but - contrary to some reports - the substance has yet to be identified.
There have been reports of pwdr sêr (also pwdre sêr or pydredd sêr, Welsh for 'star-rot') for centuries. John of Gaddesden (1280–1361), for example, mentions stella terrae (Latin for 'star of the earth' or 'earth-star') in his medical writings, describing it as "a certain mucilaginous substance lying upon the earth" and suggesting that it might be used to treat abscesses. A fourteenth-century Latin medical glossary has an entry for uligo, described as "a certain fatty substance emitted from the earth, that is commonly called 'a star which has fallen'". Similarly, an English-Latin dictionary from around 1440 has an entry for 'sterre slyme' with the Latin equivalent given as assub (a rendering of Arabic ash-shuhub, also used in medieval Latin as a term for a 'falling' or 'shooting' star).
The Oxford English Dictionary lists a large number of other names for the substance, with references dating back to the circa-1440 English-Latin dictionary entry mentioned above: star-fallen, star-falling, star-jelly, star-shot, star-slime, star-slough, star-slubber, and star-slutch.
A long article in the paranormal magazine Fate declared Star Jelly to be of extraterrestrial origin, calling it "cellular organic matter" which exists as "prestellar molecular clouds" which float through space.
In The Book of British Amphibians and Reptiles (page 138) author M Smith, explains that Star Jelly is most likely formed from the glands in the oviducts of frogs and toads. Birds and mammals will eat the animals but not the oviducts which, when they come into contact with moisture, swell and distort leaving a vast pile of jelly like substance sometimes also referred to as Otter Jelly.
In 1910, T. Mckenny Hughes ruminated in Nature as to why meteors were associated with star jelly by poets and ancient writers, and observed that the jelly seemed to "grow out from among the roots of grass".
- Thomas Pennant in the 18th century believed the material to be "something vomitedup by birds or animals".
- Nostoc, a type of fresh water blue-green algae (cyanobacteria) forms spherical colonies made of filaments of cells in a gelatinous sheath. When on the ground, it is ordinarily not seen; but after rainfall it swells up into a conspicuous jellylike mass which is sometimes called star-jelly.
- The Massachusetts Department of Environment Quality Engineering examined the "star fall" which dropped on North Reading, but the only results were that the material was "non-toxic".
- One scientific speculation has pointed towards frog spawn which has been vomited up by amphibian-eating creatures (notably European Polecats), though no frog spawn has ever approached the size of some reported cases of star jelly. TheGerman terms Sternenrotz (star snot) and Meteorgallerte (meteorite jelly) are known to refer to more or less digested frog spawn vomited by predators (Schlüpmann 2007). This is quite easy to identify by its smell and found in winter and early spring near frog spawning sites.
- Scientists commissioned by the National Geographic Society have carried out tests on samples found in the United States, but have failed to find any DNA in the material.
- Slime molds are possible causes, appearing suddenly, exhibiting a very gelatinous appearance at first and later changing to a dust-like form which is dispersed by rain and wind. The colours range from a striking pure white as in Enteridium lycoperdon, to pink as in Lycogala epidendrum, to purple, bright yellow, orange, and brown.