When Jeremy Hansen, the Canadian astronaut, embarks on the Artemis 2 mission beyond the moon, part of his duties will involve observing the far side of the moon, which is unseen from Earth. Simultaneously, scientists on Earth will also be monitoring closely as they plan to deploy telescopes and robots to explore deep space from that vantage point.
The moon, gravitationally locked to Earth, presents two distinct faces. One side is perpetually facing Earth, and the other side is directed towards deep space. Despite being termed the “dark side,” the far side receives as much sunlight as the Earth-facing side.
Characterized by a rough, crater-covered terrain, the far side of the moon contrasts with the near side, known for its vast flat plains called “Maria,” meaning seas in Latin. The far side offers a tranquil setting shielded from Earth’s artificial radio interference, making it an attractive location for astronomers to install radio telescopes.
Access to the far side of the moon is exclusive to spacecraft, granting Hansen a rare opportunity to witness sights unseen by many since the Apollo era. Unlike the Apollo astronauts who orbited close to the equatorial regions, Hansen will venture 7,500 kilometers beyond the moon during the Artemis mission, providing a panoramic view of the entire globe.
During their lunar flyby, the Artemis crew will closely observe the lunar surface through the windows, leveraging the human eye’s ability to discern subtle details crucial for potential spacecraft landings, such as color variations and surface roughness.
One proposed mission to the far side involves the TSUKUYOMI project, a Lunar Meter Wave Telescope by Japan, which aims to establish a radio dish array on the far side to delve into the universe’s early days during the dark ages. This era, following the big bang approximately 400,000 years later, was characterized by a predominantly neutral hydrogen gas phase emitting faint radio signals detectable by sophisticated instruments on the moon.
These signals from the dark age hold potential to unveil the role of dark matter in shaping the early universe, ultimately influencing the formation of stars, galaxies, and planets. Future plans include deploying additional radio observatories on the far side, such as LuSEE Night and NASA’s Farside Seismic Suite, alongside ongoing lunar observatory initiatives by NASA and ESA.
While human moon missions prioritize colony establishment and water ice exploration at the south pole with Earth always in sight for communication, the hidden far side of the moon will host a multitude of robots gazing toward the universe’s edge and origins to unravel the mysteries of cosmic beginnings.
