What was that light in the sky? A field guide to satellites, planes, meteors and more
A steady moving dot, a line of lights, a flash, a glowing jellyfish: most strange lights have an everyday explanation. A quick checklist by how the light moved and looked, and how to check what was overhead at that moment.
Start with three questions
Did it move? How fast, and in a straight line? Did it blink, flash, or shine steadily? Almost every light in the night sky can be identified from those answers, plus the time and the direction you were facing. Write them down right away; memory changes fast.
It didn't move: a planet or a star
A very bright point that stays put for minutes (it drifts slowly with the stars over hours) is usually Venus or Jupiter. Venus in particular gets reported as a UFO every year: it is dazzling, low in the evening or morning sky, and seems to follow you when you drive.
A bright star low on the horizon that flashes red, green and blue is usually Sirius or another bright star. Thick air near the horizon breaks its light into colours as it twinkles.
It moved steadily, took minutes: a satellite
A steady, non-blinking point moving smoothly across the sky in a straight line over 2–6 minutes is almost certainly a satellite. The International Space Station is the brightest, brighter than any star. Satellites often fade out partway across the sky: they have entered Earth's shadow.
A line of evenly spaced dots moving one after another, like a string of pearls, is a Starlink train: satellites launched in the last few days that have not yet spread out. These appear for a week or two after each launch and cause a great many reports.
It blinked: an aircraft or a drone
Planes carry a red light on the left wing, a green one on the right and white strobes that flash regularly. If you hear an engine or see blinking colours, it is an aircraft. Drones show similar lights, move irregularly, hover and change direction. Light shows with hundreds of drones forming shapes are increasingly common at events.
It was fast and gone in a second: a meteor
A streak that crosses part of the sky in a second or less is a meteor. Very bright ones, fireballs, can light up the ground, show colours and break into pieces. A slow, long-lasting train of glowing fragments moving together across the sky over a minute or so is different: that is often space debris or an old rocket stage re-entering.
Other common culprits
- A glowing 'jellyfish' or spiral cloud after dusk or before dawn: the exhaust plume of a rocket launch lit by the Sun high above, sometimes visible hundreds of kilometres away.
- Orange lights drifting slowly with the wind, often in a group, flickering: sky lanterns.
- A short, sudden flash from a 'star': sunlight glinting off a tumbling satellite or rocket body.
- Steady lights that seem to sway: tower lights or a planet, with your eye's own drift (the autokinetic effect) making them seem to move.
Check what was overhead
Our identifier asks for the time, your location and the direction you looked, then checks every tracked satellite, rocket stage, the ISS, Starlink trains, the planets and active meteor showers for that moment. Most of the time, the answer is in the list.