Meteor Cut

Point a camera at the night sky, record for an hour or a whole night, and give Meteor Cut the video. It finds every meteor and cuts a highlight video of just those moments, with each meteor boxed, its trail drawn and its speed shown, and a panel listing them all from fastest to slowest. It stacks every meteor of the night onto one starry picture, cuts vertical clips of the best ones for Shorts and Reels, ranks the longest and brightest, picks out satellites and planes, draws every trajectory with the shower's radiant, maps where meteors appeared, and writes it all to CSV. Given the time (and, ideally, the stars), it names each meteor's shower and estimates its magnitude. It can also watch a camera live and keep only the meteors.

Meteors are found and followed by Sky Tracker's MotionTracker, which looks for what got brighter since the previous frame: the head of a meteor rather than the trail it leaves.

_{Made by Meteor Cut from one hour of the Perseids livestream LIVE Perseids Meteor Shower, Skywatch #265 by Skywatchers, 12-13 August 2026. Footage © Skywatchers.}

Install

pip install meteor-cut

Meteor Cut needs Python 3.10 or later. It installs the Sky Tracker SDK, whose motion tracker it uses in the mode that is free: no licence key or sign-up needed.

Quick start

meteor-cut night.mp4
meteor-cut night.mp4 --focal 14 --sensor full-frame --tilt 40 --show all
meteor-cut night.mp4 --start "2026-08-12 22:30" --site 50.45,30.52 --solve
meteor-cut watch 0 -o tonight            # a live camera; Ctrl+C to stop

Or start the upload page and use it from your browser. It runs on your computer; videos never leave it. Each video's results are kept in a folder of their own under ~/Meteor Cut (choose with --results), named after the video and the time, so they stay after the server stops; the uploaded copy of the video is deleted once processed.

meteor-cut serve            # then open http://127.0.0.1:8765

From Python:

from meteor_cut import Lens, process

result = process("night.mp4", "night-meteors", lens=Lens(focal_mm=14, tilt_deg=40))
for meteor in result.found.meteors:
    print(meteor.label, f"{meteor.start_s:.1f} s", f"{meteor.motion.angular_speed_deg_s:.1f} deg/s")

What you get

Here is one hour of the 2026 Perseids, from the same livestream as the picture at the top: 32 meteors, 23 of them from the Perseid radiant, and 88 satellites.

_{Made by Meteor Cut from one hour of the Perseids livestream LIVE Perseids Meteor Shower, Skywatch #265 by Skywatchers, 12-13 August 2026. Footage © Skywatchers.}

Results go to night-meteors/ beside the video (choose with -o):

Speeds

One camera cannot see a meteor move towards or away from it, so the km/s figure is the speed across your view, at the height meteors burn (95 km by default, --altitude): the real speed is at least that. Values well above 72 km/s, the fastest a meteor can enter the atmosphere, mean the lens or tilt is wrong. The lens is assumed to be rectilinear (a normal wide-angle lens, not a fisheye), and the video to show the sensor's full width.

Time, place and stars

Three optional pieces of information make the results richer:

--solve identifies the stars with astrometry.net on your computer: install it (brew install astrometry-net on macOS, apt install astrometry.net on Debian and Ubuntu), then run meteor-cut star-index once to fetch the five small index files a wide-angle camera needs (1.6 MB). Without installing anything, run meteor-cut sky-frame night.mp4, upload the picture at nova.astrometry.net, download wcs.fits from its result page and pass --wcs wcs.fits. The camera must not move during the recording; in a compilation the solution holds for the scene its frame came from.

Showers come from the IAU Meteor Data Center's list of established showers, and magnitudes from the stars of the Yale Bright Star Catalogue in the same frames. Magnitudes from compressed video are rough (half a magnitude or so), and one marked ≤ saturated the camera, so it was at least that bright. A meteor of magnitude -4 or brighter is a fireball.

Watching live

meteor-cut watch 0 -o tonight                      # the first camera or capture card
meteor-cut watch rtsp://camera.local/stream -o tonight --fov 90 --minutes 480

Live mode keeps the last few seconds in memory and saves a clip of each meteor (from just before it appeared) as soon as the rules have confirmed it, about ten seconds after it ends: lamps and people are told apart by what else moves near them. It writes clips/, meteors.csv as it goes, and composite.png and summary.json when it stops. A video file works too, read as fast as the computer allows, as if it were live.

Options worth knowing

meteor-cut --help, meteor-cut process --help and meteor-cut watch --help list everything.

How it works

In short: Sky Tracker follows everything that moves, twice (every frame for meteors, about five frames a second for satellites and planes). Meteor Cut then keeps what moves like a meteor: straight, fast, over in a few seconds, and never twice in the same place. Lights that flare in one spot, people, and groups of things moving together are left out, and scene cuts in compilations are handled. docs/how-it-works.md explains each step and its limits.

Contributing

Bug reports with a sample video are the most useful thing you can send. See CONTRIBUTING.md to set up a development copy; the tests run without a Sky Tracker licence.

Licence

Meteor Cut is MIT-licensed: see LICENSE. It uses the Sky Tracker SDK, which has its own licence. The bundled star catalogue (Yale Bright Star Catalogue, Hoffleit & Warren 1991) and meteor shower list (IAU Meteor Data Center; Jenniskens et al. 2020, Jopek & Kanuchova 2017) are scientific reference data: see src/meteor_cut/data/README.md. The upload page and report use the Manrope typeface, included under the SIL Open Font License (src/meteor_cut/web/static/fonts/Manrope-OFL.txt). The Deneb Systems name and logo are trademarks of Deneb Systems and are not covered by the MIT licence: forks may keep the logo where it credits the original project, but should not use it to brand their own.