With a lot of science, we look for similarities between objects, and then try and determine if similar science is responsible for those similarities. There are cases, however, where we know form does not follow function. For instance, researchers using radio telescopes spotted what appears to be a jellyfish in space, and it’s a pretty good guess that the tentacles of light aren’t there to sting prey. 

This odd shape is only visible in a small range of radio wavelengths. In fact, with a sensitive enough FM radio, you could detect it, but if you go past the dial to 200MHz, it disappears. According to lead author Torrance Hodgson: We’ve had to undertake some cosmic archaeology to understand the ancient background story of the jellyfish. Our working theory is that around 2 billion years ago, a handful of supermassive black holes from multiple galaxies spewed out powerful jets of plasma. This plasma faded, went quiet, and lay dormant. Then quite recently, two things happened–the plasma started mixing at the same time as very gentle shock waves passed through the system. This has briefly reignited the plasma, lighting up the jellyfish and its tentacles for us to see. 

This work is presented in The Astrophysical Journal.

As an amusing side note to this story, all the graphics were labeled “USS Jellyfish”, and we thought that just once an astronomer had given something a truly fabulous name. Well, they did, but that USS isn’t a humorous reference to ships; it is actually an abbreviation for Ultra Steep Spectrum, which is a fancy way of saying you see it FM but you don’t see it at other frequencies. So yes, this jellyfish-looking object is officially named the USS Jellyfish, and it makes its home in the Galaxy Cluster Abell 2877.

More Information

ICRAR press release

“Ultra-steep-spectrum Radio “Jellyfish” Uncovered in A2877,” Torrance Hodgson et al., 2021 March 10, The Astrophysical Journal