Astronauts from the Artemis II mission have made it home. Their journey, which began on April 1 in Cape Canaveral, Florida, took them around the Moon and farther from Earth than any human had traveled before. On April 10, they splashed down in their capsules off the coast of California. Upon landing, mission commander Reed Wiseman reported “four green crew members”, indicating that he, his NASA crewmates Victor Glover and Christina Koch, and Canadian astronaut Jeremy Hansen were all feeling well after re-entering Earth’s atmosphere. “What a trip,” he said.
This historic flight is the first time humans have visited the Moon since the Apollo 18 mission in 1972. At its farthest, the Orion capsule was 406,771 kilometers from Earth, breaking the distance record set by the crew of the Apollo 13 mission in 1970.
Artemis II’s main purpose was to serve as a test flight for future lunar missions, a test it passed with flying colors, but it also had several science goals. Many of them were tied to the color of the moon’s surface – from a distance it appeared only gray, but up close astronauts saw green, brown and even orange hues. These observations can help scientists learn the composition and history of the moon’s surface, especially on its far side, where astronauts observed some areas never before seen directly by human eyes.
However, when both Earth and the Moon were visible together, the brightness of sunlight reflected from the planet, called Earthshine, suppressed these subtle variations. “The moon turned into a sponge of light,” Koch said. “As soon as the Earth got close enough to be in my field of view to take both of them at the same time, (the moon) became dull, it turned into a sponge, it’s almost like it became matte.” In fact, Earth’s light was so bright through one of the windows during flight that the crew covered the window with an extra shirt, leading to calls for the inclusion of dedicated window shades in future missions.
The astronauts also took photographs and made sound recordings as they watched the Moon pass, including detailed descriptions of the terrain below them. “It’s those kinds of subtle observations that can ultimately inform future landing missions, future crewed missions, to understand where we can go to maximize the scientific value,” Kelsey Young, NASA’s Artemis science chief, said in an April 7 press conference. “These ultimately add up to the chronology of the Solar System, how the inner Solar System has evolved over time, which connects to the Moon as a witness plate for our planet and the inner Solar System.”
While their spacecraft was behind the Moon, the Artemis crew also got to see a solar eclipse unlike that seen from Earth, in which the Sun appeared smaller than the Moon in the sky as it disappeared behind the lunar horizon. “The eclipse happened, and then we had a human emotional response for 5 minutes looking at that sphere floating in the vastness of space,” Wiseman said. “Then right after that, someone in the cabin said, ‘Let’s see the impact flashes,’ and immediately we saw one or two or three.”
Observing impact flashes, which are momentary sparks of light caused by meteorites hitting the moon’s dark surface, was one of the mission’s science goals, because observing them could help us figure out how concerned future missions should be about meteorite impacts on the surface.
The Artemis program’s next mission, Artemis III, will not include a landing on or even a trip to the Moon, following a series of recent changes aimed at making the program faster and more practical. Instead, it will be primarily about testing the Orion capsule’s ability to dock with lunar landers in orbit around Earth. It is planned for 2027; The next lunar landing is scheduled for the Artemis IV mission in 2028.
All of these flights are part of a larger goal of creating a sustained human presence on the Moon. NASA recently announced a pivot in its plans, from a space station in lunar orbit to a base on the ground, and China’s space program has similar aspirations. The hope is that within a few decades, going to the Moon will become as routine as going to the International Space Station is now – and eventually, perhaps as routine as an intercontinental flight. Whether that’s the case or not, the images from Artemis II have been imprinted on the public consciousness, refreshing our view of the Moon.
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