This was a meteor or fireball, and it's one of the better documented ones. A small comet fragment hit the upper atmosphere over Portugal and Spain on May 18, 2024, and the blue-green color fits a very fast meteor burning up about 60 km high. The data points the same way: a brief streak lasting about five seconds, moving fast, with no sound and no blinking. Fireworks and birds or bats scored much lower, and aircraft are unlikely given how quickly it vanished. The case is archived, so this is a write-up from the site team rather than a report from someone who saw it directly.
From the archive: the WTH team wrote this up from a real event that was widely reported at the time, to show how the checks work. The sources are at the end of the description.
From the archive · #8pc5mtgde2sy
A blue-green fireball over Portugal and Spain: a comet fragment
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Sky Snapshot 11:46 PM, give or take 15 minutes
- Sky
- fully dark
- Moon
- waxing gibbous, 44° up
- Planets up
- none bright
- Bright stars
- Arcturus (south 70°), Vega (northeast 37°), Capella (northwest 6°), Procyon (west 0°)
- Weather
- clear, wind 10 km/h
- Space weather
- quiet (Kp 1)
- Sunset
- 8:44 PM
Download the snapshot card to share it anywhere.
What people saw
- When
- May 18, 2024, 11:46 PM GMT+1
- Where
- Lisbon, PT
- Looking
- north, mid in the sky
- Lasted
- 5 seconds
- Looked like
- one, blue/green, streak, fast, with a trail
- Sound
- none
Late on May 18, 2024, a vivid blue-green fireball lit up the sky over Portugal and western Spain for a few seconds, bright enough that videos from dashcams and doorbell cameras spread around the world within hours.
The European Space Agency said it was a small piece of a comet hitting the atmosphere at roughly 160,000 km/h. It likely burned up over the Atlantic about 60 km up. The blue-green color is typical of very fast meteors.
Sources:
https://www.space.com/meteor-green-fireball-spain-portugal-may-19-2024
https://earthsky.org/earth/portugal-fireball-video-and-images/
From above the area, the way they looked, and what was overhead
The map needs JavaScript. The checks below list everything it shows.
The circle is the area the report came from, rounded to about 10 km. We never show a witness's exact spot.
See it in 3D on the Sky Globe, at the moment it was seen
What it could be
-
Meteor or fireball Likely94%
- +35Over in seconds: that is a meteor.
- +20Very fast streaking motion fits.
- +15A streak or trail is the meteor signature.
- +5Green, blue or orange flashes come from the glowing metals in a meteoroid.
- +4The Eta Aquariids were active that night.
-
Fireworks Doesn't fit35%
- +5Night.
- +15Brief bursts fit fireworks.
- +10Colored bursts fit.
-
Bird, bat or insect lit by a light Doesn't fit33%
- +30Fast, silent, erratic and brief at night is a bird or bat lit from below by streetlights.
What we checked
- Satellites: not checked (orbit data missing)
- Starlink trains: not checked
- Launches: none within 90 minutes and 3,000 km
- Aircraft: not checked (no flight history feed yet)
- Planets and Moon: no bright planets up, and the Moon was up
- Space weather: quiet (Kp 1)
- Weather: clear
- Meteor showers: Eta Aquariids
How we worked this out
We took a snapshot of the sky from 15 minutes before to 15 minutes after May 18, 2024, 10:46 PM UTC at 38.72, -9.14, and scored 19 possible explanations. Each one starts from how common it is, then gains or loses points for every detail the witness gave and every record we found. The points are listed next to each reason above. "Likely" means 80% or more and "Possible" means 50 to 79%. Anything lower doesn't fit, and if nothing reaches 50%, the case stays unexplained.
Sources: launch schedule from Launch Library 2; planetary Kp from GFZ Potsdam; weather from Open-Meteo; Sun, Moon and planet positions worked out on our server with astronomy-engine. Engine 0.4.0, snapshot v2, worked out Oct 29, 2026, 4:53 PM UTC.
Not available for this report: satellite passes.
Discussion 0 replies
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