Mysterious jellyfish-like structure seen in skies over United States. It's not aliens

A SpaceX Falcon 9 launch produced a glowing, jellyfish-shaped plume over the US. Here's what causes the phenomenon and whether it poses any danger.

In Short

• Dragon spacecraft carries over 2,860 kg of supplies and experiments
• Launch created glowing jellyfish-shaped cloud in early morning sky
• Phenomenon is visual, not dangerous, lasting a few minutes only

A glowing, jellyfish-shaped cloud lit up the early-morning sky over parts of the United States on Tuesday, October 13, leaving people wondering what they were seeing.

The unusual sight appeared after a SpaceX rocket blasted off from Florida, with its bright, spreading trail resembling a giant jellyfish floating above Earth.

Despite its otherworldly appearance, the phenomenon has a scientific explanation, and it begins with yet another SpaceX launch.

WHAT WAS THE SPACEX LAUNCH ABOUT?

The Falcon 9 rocket lifted off on Tuesday at 4:03 pm IST from Cape Canaveral Space Force Station in Florida.

It carried an uncrewed Dragon spacecraft loaded with more than 2,860 kg of scientific experiments, supplies and equipment for the International Space Station (ISS).

The mission, SpaceX's 35th commercial cargo resupply flight for Nasa, also delivered the final pair of new roll-out solar arrays for the orbiting laboratory.

The Dragon spacecraft is scheduled to reach the ISS on Thursday, October 15, after a journey of about two days.

The launch, on its way to make an important delivery, left behind a spectacular view.

HOW DOES A SPACE JELLYFISH FORM?

The secret behind the space jellyfish was hidden in the timing of the launch. When rockets take off shortly before sunrise or after sunset, the sky at ground level may be dark while sunlight still reaches the rocket high above.

As Falcon 9 climbed, its exhaust plume spread out in the thin upper atmosphere. Sunlight then illuminated the expanding gases, creating a bright, rounded cloud with long, wispy trails that look like a jellyfish's tentacles.

Nasa has documented similar views in the past, as the effect is quite dreamy, and also because the glowing plume can be seen across a wide area, sometimes hundreds of kilometres from the launch site.

The shape changes rapidly as the exhaust expands and disperses, and the display generally lasts only a few minutes before fading from view.

IS THE SPACE JELLYFISH DANGEROUS?

The space jellyfish is a visual effect, not a separate object or a mysterious cloud. Its appearance alone does not indicate that a rocket has malfunctioned.

However, it is not accurate to say rocket launches have no environmental effects. The exhaust contains gases and particles, and their impact depends on the rocket and the altitude at which they are released.

For observers, the glowing plume means a beautiful view of the meeting between rocket launches, the upper atmosphere and sunlight. For the Dragon spacecraft, meanwhile, the journey continues towards the ISS, where its cargo will support astronauts and scientific research.

- Ends