When SpaceX launched NASA’s CRS-35 cargo mission to the ISS at 6:35 a.m. EDT on 13 October 2026, a giant glowing “jellyfish” spread across the dark sky. The launch came 47 minutes before sunrise: our calculation puts the Sun 10.5° below the horizon, so the ground was dark but everything above about 110 km was already sunlit, and the exhaust lit up as it climbed into the light and spread out in the thin air. Dragon carries about 2,860 kg, including the last iROSA solar arrays. Our take: twilight launches are the ones to watch.
On Tuesday 13 October 2026 at 6:35 a.m. local time, a SpaceX Falcon 9 lifted off from Cape Canaveral with a Dragon cargo ship for the International Space Station: NASA’s CRS-35 mission. Minutes later a huge glowing cloud spread across the still-dark sky, with streaks hanging below it like tentacles. NASA shared the view as a “space jellyfish”, and the pictures travelled around the world.
It is not a UFO, and nothing up there is on fire. It is the rocket’s own exhaust, lit by a Sun that had not yet risen for the people watching on the beach.
Dark on the beach, sunny 100 km up
The launch came 47 minutes before sunrise. Our calculation for Cape Canaveral shows the Sun was 10.5° below the horizon at lift-off. At that moment the ground lies in Earth’s shadow, but sunlight already reaches everything higher than about 110 km straight overhead, and even lower towards the east. As the rocket climbed past that height, its exhaust stepped out of the shadow and lit up against the dark sky.
The exhaust is mostly water vapour and carbon dioxide. Up there the air is so thin that the gas spreads out enormously, forming the glowing dome, while the trail of the climbing rocket hangs below it like tentacles. Because the rocket follows Earth’s curve on its way to orbit, the jellyfish even seems to sink towards the horizon.
Launch13 Oct 2026, 6:35 a.m. EDT
Before sunrise47 minutes
Sun10.5° below the horizon
Sunlit above≈ 110 km overhead
RocketFalcon 9 · Dragon (CRS-35)
Cargo≈ 2,860 kg for the ISS
Why the plume glows while the beach is dark
Original Astrometrik animation; heights and Earth’s curvature are exaggerated. The watcher on the beach is still in Earth’s shadow (dark area). The rocket climbs east and crosses the shadow’s edge (dashed line); above it the Sun is already shining, so the expanding exhaust lights up like a jellyfish.
What was the rocket carrying?
About 2,860 kg for the International Space Station: the last set of roll-out solar arrays (iROSA) to boost the station’s power, hardware for making artificial retinas in weightlessness, 3D heart-tissue models for drug tests, a study of how a new kind of glass forms, and brain organoids for research on Alzheimer’s, Parkinson’s and multiple sclerosis. Dragon is due to dock with the Harmony module on 15 October at about 15:00 UTC and stay for about a month before splashing down off California.
When can you see a space jellyfish?
Only around twilight, in roughly the hour or so before sunrise or after sunset, when you are in the dark but the upper atmosphere is already, or still, in sunlight. Launches from Florida and California produce them regularly. The same trick is why you can see the International Space Station at all: it shines because it is in sunlight while you stand in the dark.
Decades of UFO alarms
Rocket plumes at twilight have fooled people for decades. In September 1977 a Soviet launch from Plesetsk caused the famous Petrozavodsk UFO sighting over northern Europe, and in October 2018 a Falcon 9 launch after dusk in California set off UFO reports along the US West Coast.
Watch: the space jellyfish in under a minute
Our short animated video explains the CRS-35 jellyfish step by step.
How far below the horizon is the Sun? Slide it
Choose how far the Sun is below the horizon. We calculate the height above which the sky is already in sunlight, straight above you.
Catch the next launch
Our launch board shows every upcoming rocket launch with a live countdown, including the twilight launches most likely to make a jellyfish.
What was the jellyfish in the sky over Florida on 13 October 2026?
The exhaust plume of the SpaceX Falcon 9 that launched NASA’s CRS-35 cargo mission at 6:35 a.m. EDT. It was lit by sunlight high above the still-dark ground.
Why does a rocket plume glow before sunrise?
Above about 100 km the Sun is already up while the ground is in Earth’s shadow. At the CRS-35 launch the Sun was 10.5° below the horizon, so everything above about 110 km overhead was in sunlight.
Why does it look like a jellyfish?
In the very thin upper air the exhaust gas, mostly water vapour and carbon dioxide, expands into a wide glowing dome, and the rocket’s trail hangs below it like tentacles.
Can I see a space jellyfish from Europe or Türkiye?
Not from SpaceX launches in Florida or California, which are too far away. The same twilight effect is what makes the ISS and noctilucent clouds visible from Europe.
Sources and calculation
Sources: Space.com (12–13 October 2026) on the CRS-35 launch time, cargo and docking plans; NASA’s post of 13 October 2026 (“Space jellyfish!”); NASA Astronomy Picture of the Day, 19 March 2026 (“Launch Plume: SpaceX Jellyfish”, image by Michael Seeley); Wikipedia, “Space jellyfish” (historic cases). Sun position and shadow height calculated by Astrometrik with Astronomy Engine for Cape Canaveral. NASA’s photos are not reproduced here; the animation and the video are our own.
Positions and times were recalculated with Astronomy Engine, the sky-calculation library Astrometrik uses; times for Vienna and Istanbul are local time. The artwork on this page was drawn by Astrometrik.