A New Mission Watches Meteoroids Hit the Far Side of the Moon

Sometimes, it’s hard to remember that Earth is constantly being bombarded by literally tons of space debris daily. The larger bits form what we know as shooting stars, and most burn up in the atmosphere. Still, throughout our planet’s history, giant versions have caused devastation unlike anything else seen on this planet. Tracking these types of objects is typically done from the Earth, but a new mission set out by researchers in Italy has a novel idea – why not try to learn more about potential impactors by watching them hit the far side of the Moon?

The mission, known as the Lunar Meteoroid Impact Observer, or LUMIO, is a 12U CubeSat weighing around 22 kg. Its primary payload is the LUMIO-Cam, a visible light camera meant to detect flashes of impacts of the micrometeoroids it is intended to track.

So far, so typical – plenty of asteroid and meteoroid tracking missions are already in space, so why need another one? The most interesting thing about LUMIO is its location – at the L2 Earth-Moon Lagrange point. That puts it exactly opposite the Earth on the far side of the Moon.

This location has advantages and disadvantages – the Moon’s disk is much smaller than the Earth’s, so LUMIO could capture the entire hemisphere and watch for any impacts on the lunar surface. It’s important to note that most of the impacts would indeed be on the surface itself, since the lunar atmosphere is negligible in terms of providing energy for a micrometeoroid to burn up before impact. That is why the Moon is pockmarked with so many craters.

Also, while it’s commonly referred to as the “dark side” of the Moon, the far side is lit up half the time – and fully lit when we down on the planet experience a “new Moon.” But, when it is dark on the lunar surface, it is genuinely dark – there aren’t any lights that could be misconstrued as an asteroid strike. The L2 point has the added advantage of not suffering from “Earthshine” – reflected light from Earth that could diminish the effectiveness of the LUMIO-cam when trying to detect faint light streaks.

Difficulties abound with the placement, though, including a lack of a direct line of communication and the necessity of an automated navigation and control system. Since the Moon is literally between the CubeSat and any ground receiver that could send commands or receive data, it must be bounced off a relay satellite in order to do so.

LUMIO will also capture a large amount of data, not all of which will be useful. Since the flashes it’s looking for are very fast, LUMIO-Cam will capture about 15 frames per second. Then, onboard processing will use an algorithm to sort through the image to see if there are any flashes visible in it. Those interesting images will then be the ones sent back to Earth. 

Estimates put the number of micrometeoroids striking the Moon’s surface at as high as 23,000 times per year for micrometeoroids as small as 30 grams. Even if LUMIO only watches half of that area, it will observe impacts multiple times every day. Each is a little look into the types of debris that still exist in our local part of the solar system and maybe into what asteroids and comets they were initially a part of.

There’s a good chance the LUMIO team will be able to capture that data as well – the mission was accepted as a finalist to ESA’s Lunar CubeSat for Exploration (LUCE) SYSNOVA Competition and is currently planned for launch in 2027. Once it reaches its stable orbit, expect to see some brilliant flashes on the Lunar surface popping up new reports regularly.

Learn More:
ESA – LUMIO – New CubeSat Illuminating Lunar Impacts
Topputo et al. – LUMIO: A CubeSat at Earth-Moon L2
UT – Astronomers are Working to Put a Radio Telescope on the Far Side of the Moon by 2025
UT – Finally, an Explanation for the Moon’s Radically Different Hemispheres

Lead Image:
Depiction of LUMIO’s orbital path to the L2 Earth-Moon point.
Credit – ESA