Cape Canaveral, FL– January 2, 2024 .There’s a pretty good chance that tomorrow night’s Falcon 9 launch will produce a beautiful phenomenon known as a “space jellyfish”. Many observers, who believe they have frequently seen the phenomenon called a jellyfish before, actually saw something else instead….
The Term “Space Jellyfish” is Overused
The term “space jellyfish” has been broadly adapted and somewhat overused in describing various atmospheric events related to rocket launches. With the marked increase in launch cadence over the past two years, spectators frequently mistake seeing beautiful gaseous displays following virtually any night launch as a “space jellyfish”. While sometimes spectacular, these various sights are quite common, whereas a true “space jellyfish” is actually quite rare. There are two common launch related visuals that are often misidentified as a jellyfish.
One of the most common sights many believe is a “space jellyfish” is the widening of a rocket’s plume of gasses at high altitude. This is most often visible right after stage separation and results with the absence or substantial loss of atmospheric pressure, which tends to “hold together” an exhaust plume at lower altitudes.
As a rocket moves further away from it’s superheated exhaust gasses, the more they spread out, resulting in a secondary display also mistaken for a “space jellyfish”. This display of lingering hot gasses, which is under far less pressure, could more accurately be described as an atmospheric nebula.
What does it take to make a true space jellyfish?
A true space jellyfish is a much more rare occurrence, and to see one, another key ingredient has to be present…high altitude sunlight. Without it, you don’t have a true jellyfish. To have a really good chance to see a jellyfish, a launch needs to occur generally in the window of one half hour before sunrise or one half hour after sunset,
The sunlight makes ALL the difference. A true jellyfish looks like an expanding tear in the very fabric of the sky, allowing darkness to be replaced with a beautiful bright blue light, similar to a clear blue sky itself. When a rocket’s exhaust gases interact with sunlight in an otherwise dark sky, it’s as if you were looking through a cosmic window into a place where the sun never set. The full beauty of a space jellyfish is spectacular from anywhere, but many say it’s even better farther from the launch site because of the contrast with the surrounding dark sky. Like a launch, a jspace jellyfish can be seen from hundreds of miles away in clear weather. A good example of a true jellyfish was the infamous Falcon 9 launch in May of 2022 just before dawn.
With tomorrow’s sunset set to occur at 5:39 PM and a launch set for 6:04 PM, the chances of seeing a true space jellyfish are excellent. Keep an eye to the shy!
