NASA's Artemis 2 astronauts saw flashes on the far side of the moon that cameras struggle to capture. Here's why scientists are excited
The Artemis 2 astronauts remained vigilant while zipping around the far side of the moon last month, on the ready to record meteoroid impact flashes on the lunar landscape.
Their diligence was rewarded. The four crewmembers reported seeing several impact flashes — flickers of light created when a meteoroid hits the lunar surface and vaporizes.
Citizen scientists help out
Artemis 2, the first crewed moon flight since Apollo 17 in 1972, launched from Florida's Space Coast on April 1 and flew around the far side of the moon on April 6.
As the astronauts scrutinized the moon that day, so did citizen scientists here on Earth. They were also looking for impact hits, although they would likely not have spotted the same ones as the crew.
Those observations were gathered as part of the newly launched Impact Flash citizen science project under the auspices of the Geophysical Exploration of the Dynamics and Evolution of the Solar System (GEODES), a unit within the NASA Solar System Exploration Research Virtual Institute.
The Impact Flash effort is geared to gather more data on the location and brightness of flashes throughout recent and upcoming Artemis moon missions.
"These flashes are vital to scientists who study the moon," notes the Impact Flash website. "By tracking when and where they happen, scientists can learn how often impacts of different sizes occur, what kinds of craters they create, and how the shock waves travel through the moon's interior."
When combined with data from NASA's moon-circuiting Lunar Reconnaissance Orbiter (LRO), future lunar surface instruments, and crew observations, the citizen science observations "can provide valuable constraints on the origin and characteristics of impactors, as well as craters that form from the impacts," Wasser said.
Observation window
The Artemis 2 astronauts' impact-flash observation window extended out onto the lunar near side in darkness, Benjamin Fernando, of the Department of Earth and Planetary Sciences at Johns Hopkins University in Baltimore, told Space.com.
In a paper posted earlier this year on the preprint server EarthArXiv, Fernando and colleagues reported that coordinated impact flash observations seen both from Earth and from lunar flyby/orbit will allow more detailed information to be gathered about the timing, location and dynamics of flashes than is possible from either method alone.
Joint observation campaigns enable researchers to better constrain the impact flux on the moon and also the associated impact hazard on the lunar surface, Fernando and his colleagues concluded.
Moon base implications
Updated knowledge about the meteoroid impact flux also plays into planning for Artemis Base Camp, the outpost NASA plans to build near the moon's south pole.
"To design for longevity, one must account for the myriad environmental hazards that a long-duration outpost will face — among them radiation, extreme thermal cycling, regolith dynamics, seismic shaking, dust, and, of particular importance to this work, impacts," notes a 2025 study led by Daniel Yahalomi, now a Torres Postdoctoral Fellow at MIT.
The lunar south pole offers a natural reduction in impact risk relative to equatorial sites, according to the study, "supporting its selection for sustained human presence."
Furthermore, currently available shielding technology "is sufficient to suppress micrometeoroid hazards by nearly five orders of magnitude, reducing the effective risk to a manageable level for current habitat designs," Yahalomi and his research colleagues concluded.
Big science haul
Hunting for impact flashes was one of many science tasks for the astronauts during their historic April 6 flyby. The Artemis 2 Lunar Science Team remains busy analyzing the mission's science haul — gathered with the aid of 31 cameras aboard the Orion capsule "Integrity" — and archiving it all on NASA's Planetary Data System.
"Within six months, all imagery of the Earth and moon taken by crew and vehicle cameras, audio recordings of the crew's science observations, and accompanying transcripts will be publicly available for the broader science community to analyze," Wasserman said.
