Demystifying the Legends: The Real Composition
For centuries, sightings of translucent, gelatinous blobs appearing suddenly in fields and on lawns have mystified observers, inspiring names like 'star jelly', 'astromyxin', and 'witch's butter'. Ancient folklore tied its mysterious arrival, often after rain, to celestial events like meteor showers. However, scientific investigation has progressively chipped away at the myths, revealing that this substance is far from extraterrestrial in origin. While some reports remain inconclusive, the ingredients behind most instances of star jelly can be traced back to a few specific biological or, in some rare cases, inorganic sources on Earth.
The Cyanobacteria Connection: Nostoc commune
One of the most frequently identified components of star jelly is a species of cyanobacteria known as Nostoc commune. This organism is found all over the world and is often mistaken for a type of algae due to its photosynthetic nature. It is known for its ability to survive in extreme conditions, from hot springs to polar regions, by entering a dormant, dehydrated state.
When dry, Nostoc commune appears as a small, dark, crusty clump, often inconspicuous among soil and gravel. However, when exposed to moisture from rain or dew, it rapidly absorbs a significant amount of water—sometimes up to 40 times its dry weight—and swells into a large, prominent, green, jelly-like mass. This rapid transformation perfectly explains the 'sudden' appearance and equally mysterious disappearance of star jelly as it dries out again.
Characteristics of Nostoc commune Star Jelly
- Appears green or bluish-green when moist, and black and crusty when dry.
- Cells are embedded in a gelatinous sheath.
- Grows in soil, gravel, and unpaved areas.
- Rapidly swells upon absorbing moisture, and shrinks when it dries.
- Can survive long periods of dormancy.
The Amphibian Theory: Regurgitated Spawn
Another significant biological ingredient in star jelly is amphibian spawn, or more accurately, the gelatinous oviducts of frogs or toads. This theory is supported by observations and even DNA evidence from samples analyzed by researchers. It is proposed that predators, such as birds or other animals, consume frogs and toads but find the spawn material indigestible and distasteful, causing them to regurgitate it.
The unfertilized, regurgitated spawn then absorbs rainwater and swells dramatically, creating the mysterious, clear to grayish-white jelly-like masses seen on the ground or even in trees. A key finding from a BBC investigation confirmed the presence of frog DNA in a specimen, lending strong credibility to this explanation for many recorded incidents.
The Fungal and Slime Mold Hypothesis
Certain fungi and slime molds can also contribute to star jelly sightings. One example is Myxarium nucleatum, a clear, gelatinous fungus that grows on decaying wood. Its appearance can be mistaken for the mysterious substance. Similarly, slime molds like Enteridium lycoperdon start with a gelatinous appearance before transforming into a dust-like form. Their various colors could account for some of the varied reports of the jelly's hue.
Other Potential Contributors
Beyond the primary biological suspects, some sightings of star jelly may have more prosaic, inorganic origins. These could include:
- Sodium polyacrylate: In one case, blue balls of jelly were found to be absorbent polymer granules, which had swelled after a hailstorm.
- Industrial byproducts: Some accounts trace the material to industrial waste or chemical run-off, especially in urban or industrial areas.
Comparing the Ingredients of Star Jelly
| Feature | Nostoc commune (Cyanobacteria) | Amphibian Spawn | Slime Molds & Fungi |
|---|---|---|---|
| Primary Composition | Gelatinous colony of photosynthetic bacteria. | Swollen oviducts from unfertilized eggs. | Myxogastrids, or gelatinous fungi. |
| Appearance | Green/bluish when wet, black/crusty when dry. | Translucent, grayish-white jelly. | Varies widely; can be clear, white, yellow, or pink. |
| Catalyst | Rain or high moisture levels. | Rain, dew, or other sources of water. | Often requires moist, cool conditions and organic matter. |
| Location | Open land, gravel, fields, pavements. | Near ponds, marshy areas, in grass or trees. | Decaying logs, soil, moist forest floors. |
| Duration | Appears after rain, shrinks as it dries. | Can break down and disappear over time. | Often changes form, eventually becoming a dust-like mass. |
Conclusion: A Terrestrial, Not Celestial, Mystery
While folklore has long held that star jelly is a substance fallen from the heavens, modern science offers a range of compelling terrestrial explanations. From the moisture-absorbing cyanobacteria Nostoc commune to the regurgitated spawn of frogs and toads, the ingredients are a fascinating and entirely natural aspect of our ecosystem. Other explanations, involving fungi, slime molds, or even modern industrial polymers, show that not all mysterious blobs are the same. The phenomenon of star jelly, though no longer a cosmic riddle, remains a captivating example of how environmental conditions and a little animal activity can create a truly puzzling and visually dramatic natural event.
