NASA Releases Artemis II Lunar Science Data, Including Faint Impact Flashes

The Artemis II crew of four astronauts traveled around the Moon and created a scientific record through photographs, spoken observations, drawings and annotations, NASA said. The agency has also released the Artemis II Preliminary Lunar Science Report, the Artemis II Lunar Science Operations Report and the Artemis II Lunar Science Data User Guide.

Among the most striking observations were five extremely faint "pinprick" bursts of light that the astronauts reported seeing from 46,000 miles away. Lunar scientists had asked the crew to watch for tiny flashes sparked by rocky fragments hitting the Moon. After ruling out other possible sources, including cosmic rays or reflections from the spacecraft, the science team confirmed the sightings, the report said.

The impact flash observations occurred during a planned loss of communications while the Artemis II crew was on the far side of the Moon. Apollo astronauts saw similar flashes from lunar orbit, but the Artemis crew likely caught the faintest ever seen with the unaided eye. From the brightness of the flashes, scientists estimated that the incoming rocks were each no more than a couple of inches wide. Despite their small size, the rocks were traveling thousands of miles per hour and produced just enough light upon impact to be visible.

A nearly hour-long total solar eclipse that the crew experienced while passing by the Moon's far side created ideal dark conditions for spotting such subtle bursts. With no atmosphere to slow or burn up incoming debris, projectiles slam freely into the lunar surface. The crew's direct observations of this process on the Moon's far side provided a rare dataset that will help scientists understand how often these small impacts occur, which is essential for assessing long-term risks to future lunar habitats and infrastructure.

The crew also reported seeing subtle hues of gray, black, brown, tan, white, green and blue across the Moon's surface. This muted rainbow offers clues to the rocks and minerals that make up different lunar regions, helping scientists piece together how the Moon, and by extension Earth, evolved over time, according to NASA.

When the crew reported the flashes, Mission Control responded, "Amazing news." Space.com reported that when a Mission Control operator looked over at the Science Evaluation Room, "they were jumping up and down, literally."

NASA blogged this week that the data have been uploaded to the Planetary Data System. The agency described the release as the "sights and sounds of science," according to the Slashdot report.