When Jeremy Hansen, a Canadian astronaut, embarks on the Artemis 2 mission beyond the moon, one of his tasks will involve observing the far side of the moon, which remains unseen from Earth. Simultaneously, scientists on Earth are keenly observing as they plan to deploy telescopes and robots to explore deep space from that vantage point.
The moon presents two distinct faces due to its gravitational lock with Earth, with one side constantly facing our planet and the other side oriented towards deep space. While often referred to as the “dark side,” this is a misnomer as it receives as much sunlight as the side facing Earth.
Characterized by a rugged, crater-filled terrain, the far side of the moon contrasts with the near side, which features expansive flat plains known as “Maria,” a term derived from the Latin word for seas. This region offers a tranquil setting shielded from terrestrial radio interference, making it an appealing location for astronomers to set up radio telescopes.
Accessing the far side of the moon is only possible via spacecraft, granting Hansen a rare opportunity to witness sights that few have seen since the Apollo missions. Unlike the Apollo astronauts who orbited close to the lunar surface, Hansen’s trajectory on Artemis will extend 7,500 kilometers beyond the moon, allowing him a panoramic view of Earth from space.
During the Artemis mission’s lunar flyby, the crew will closely observe the moon’s surface, utilizing the human eye to discern subtle details that cameras might overlook. These observations, including variations in color and shading, can provide valuable insights into ground conditions crucial for future lunar missions.
Among the proposed missions to the far side is the Japanese project TSUKUYOMI, which aims to establish a radio telescope array to explore the universe’s early stages, known as the dark ages. By detecting faint radio signals from the neutral hydrogen gas era post-big bang, researchers hope to unravel mysteries surrounding dark matter’s influence on the universe’s evolution.
Future plans include deploying additional radio observatories on the moon’s far side, such as LuSEE Night from the University of Boulder Colorado and NASA’s Farside Seismic Suite, designed to study moonquakes. Both NASA and ESA are also developing lunar observatories, marking the initial phases of potential breakthroughs in space exploration.
While human moon missions focus on colony establishment and water ice discovery at the south pole, landing sites will maintain a direct line of sight with Earth for communication purposes. Meanwhile, on the hidden side of the moon, an array of robots will silently peer into the cosmos, delving into the universe’s origins and evolution.