When Jeremy Hansen, a Canadian astronaut, embarks on the Artemis 2 mission beyond the moon, part of his responsibilities will involve observing the far side of the moon, which remains hidden from Earth’s view. Scientists on Earth are also closely monitoring this exploration, as they intend to deploy telescopes and robots to investigate deep space from that remote location.
The moon, being gravitationally locked to Earth, always presents one side to our planet while the other side faces out towards space. Despite being commonly referred to as the “dark side,” this is a misnomer as the far side receives an equal amount of sunlight compared to the Earth-facing side.
Distinguished by a rugged, crater-filled terrain, the far side of the moon starkly contrasts the smooth, flat plains known as “Maria” on the near side. This secluded area is shielded from Earth’s artificial radio interference, making it an appealing spot for astronomers seeking to establish radio telescopes.
Exploration of the far side of the moon is exclusive to spacecraft, affording Hansen a unique opportunity to witness sights seldom seen by humans since the Apollo era. Unlike the Apollo astronauts who orbited near the equatorial regions, Hansen’s Artemis flight path will extend 7,500 kilometers beyond the moon, providing a panoramic view of the entire globe and a first-time spectacle of the Earth and moon in unison.
During the moon flyby, the Artemis crew will conduct detailed visual assessments of the lunar surface, leveraging the human eye’s ability to discern subtle variations in color and shade that cameras might overlook. These distinctions reveal essential ground characteristics such as dust levels and surface roughness, pertinent for future spacecraft landings.
One of the proposed missions for the far side entails the deployment of the Japanese TSUKUYOMI, or Lunar Meter Wave Telescope, to establish a radio dish array aimed at unravelling the mysteries of the universe’s early days during the “dark ages.” This epoch, characterized by a predominantly neutral hydrogen gas state devoid of light emission, offers insights into the influence of dark matter on the universe’s evolution, potentially shaping the formation of celestial bodies.
Plans are in place for additional lunar observatories, including the TSUKUYOMI prototype’s anticipated landing near the moon’s south pole in 2027 to 2028, with further expansions slated for the 2030s. Collaborative efforts involving robotic observatories like LuSEE Night from the University of Boulder Colorado and NASA’s Farside Seismic Suite aim to enhance lunar exploration capabilities and scientific understanding.
While human moon missions prioritize colony establishment and water ice exploration at the south pole, landing sites will maintain a line of sight to Earth for communication purposes. Meanwhile, on the far side of the moon, a multitude of robots will silently gaze towards the cosmos, delving into the universe’s origins and evolution from the unseen vantage point.