Lunar impact flashes (LIFs) are generated when a meteoroid, a solid object in the Solar System (typical sizes are centimeters to decimeters in diameter), hits the lunar surface at many kilometers per second and makes a small crater. Part of the energy of the impact is converted into a short flash, which can be observed with telescopes and a video camera.

The aim of this project is to gather observations of lunar impact flashes around the time of the maximum of the Geminid meteoroid stream, from 12 to 14 Dec 2025. This will help train amateur astronomers in the skills of observing Lunar Impact Flashes. It will prepare them for a citizen science programme to support the ESA LUMIO CubeSat mission, due to launch in 2028. LUMIO will observe LIFs against the lunar far-side, whilst orbiting around the so-called Lagrange point, L2, of the Earth-Moon system. Earth-based telescopic observations are needed during the LUMIO mission to help compare and calibrate near and far-side impact flash rates. But it is important that we start forming observing teams now to be ready for the mission in 2 years time.

We would like as much video coverage of the night or earthshine portion of the Moon as possible from around the world, to demonstrate the useful capabilities of amateur astronomers to contribute to scientific studies.

Of course, professional observers are very welcome too!

Because of issues with false flashes from cosmic rays, artificial objects sunglint etc., we strongly encourage simultaneous observations from widely geographically separated observers. This is an excellent way to discriminate true flashes from the noise.

If you wish to contribute to this campaign, please register via the top right button.

The study of these impact flashes will help us to better constrain the impact rate of these small objects on the Moon. This is relevant for future human exploration of the Moon - we will want to know how many objects, and more importantly impact ejecta, might hit a Moon base, lander, rover, or a spacecraft orbiting the Moon. It is also important for science as newly formed craters have and will be discovered, that are linked to specific impact flashes.

Observing these impact flashes can be done with equipment that many amateur astronomers have access to. Impact flashes have been observed with telescopes as small as 13 cm aperture. Of course, larger aperture scopes, permit fainter (and more frequent) flashes to be detected. Successful recordings have been done with analog Watec or digital ASI type cameras capable of videoing the night side of the Moon at least 10 frames per sec and capable of recording starts down to magnitude 10 at these frame rates. The typical time between detectable impact flashes is a few hours but as there is a strong meteor shower on during 12-14 Dec, we would expect to capture a few impacts during this time.