The four astronauts aboard Artemis 2 reported seeing several lunar impact flashes as they flew around the far side of the moon last month, giving researchers a rare look at meteoroid strikes from human eyes in space. The lights were seen on April 6 during the first crewed moon flight since Apollo 17 in 1972.
Molly Wasser said the flashes were observed with the unaided eye. She added that it is extremely difficult to capture impact flashes with a camera, making trained crew members valuable observers for the mission.
Artemis 2 launched from Florida's Space Coast on April 1 and carried the crew into lunar orbit before the close pass around the moon's far side. The flashes were described as brief flickers of light created when a meteoroid hits the lunar surface and vaporizes. Early data indicates that the flashes were seen on the far side of the moon.
The observations were gathered for the newly launched Impact Flash citizen science project, which operates under the Geophysical Exploration of the Dynamics and Evolution of the Solar System, a unit within the NASA Solar System Exploration Research Virtual Institute. The project is intended to collect more data on where flashes appear and how bright they are across recent and upcoming Artemis moon missions.
Scientists say the timing and location of these flashes matter because the data can help them learn how often impacts of different sizes occur, what kinds of craters they create and how shock waves travel through the moon's interior. NASA plans to combine crew observations with information from the Lunar Reconnaissance Orbiter and future lunar surface instruments.
There is also a built-in challenge to the effort. Benjamin Fernando said the Artemis 2 astronauts' observation window extended onto the lunar near side in darkness, a reminder that even when crews have a clear view, the conditions are not ideal for tracking brief flashes. Fernando and colleagues argued in a paper posted earlier this year on EarthArXiv that coordinated impact flash observations from Earth and from lunar flyby or orbit will allow more detailed information to be gathered.
For now, the significance is straightforward: Artemis 2 did more than mark a return to the moon. It also provided a fresh set of lunar impact flashes NASA Artemis researchers can use to sharpen a growing picture of how the moon is constantly being struck.