Lunar Far Side Unveiled: A Revealing Glimpse of the Moon's Hidden Side

In the October 2013 issue of an unspecified website, astronomer and science journalist Ade Ashford delved into the intriguing world of the Moon's far side. This often-misunderstood hemisphere, which always faces away from Earth, offers a stark contrast to the near side, with its vast basaltic lava flows, or maria.

The far side's rough, heavily cratered terrain is a testament to its tumultuous past. It was here, some 4.5 billion years ago, that the Moon was born from the violent collision between the proto-Earth and a Mars-sized body [1]. Today, the only places on the Moon's surface permanently bathed in shadow are a few deep craters at the north and south poles.

The far side's less volcanically active nature can be attributed to several factors. Firstly, the far side crust is about 15 km thicker on average than the near side crust, making it more difficult for magma to reach the surface and erupt as volcanic lava flows [2][3]. Secondly, the near side experienced more volcanic activity, producing the dark maria that cover nearly one-third of its surface, whereas only a few percent of the far side shows evidence of mare volcanism [2].

Hypotheses for this asymmetry include asymmetric tidal heating early in lunar history when the Moon was closer to Earth, and possibly a slow-velocity impact of a second moon forming the thicker far side crust [3]. Newer data confirm that these differences extend deep into the Moon’s mantle, affecting its internal processes and volcanic history [5].

One of the most striking features on the far side is the South Pole-Aitken Basin, a massive impact crater over 2,400 km wide and around 13 km deep [6]. Discovered in 1962, this basin supports the theory of the Moon's violent genesis and provides a glimpse into its tumultuous past.

Despite its inhospitable appearance, the far side holds potential for future exploration. For instance, a radio telescope on the Moon's far side would be shielded from electromagnetic interference by nearly 3,500 km of rock, making it an ideal location for sensitive astronomical observations [4]. The two-week-long frigid lunar night would also make it easy to keep sensitive detectors super cold.

The far side of the Moon has long been a subject of fascination, with the phrase 'dark side of the Moon' often used to refer to it. However, technically, the far side is only the 'dark side' at the instant of Full Moon [7]. The Soviet Luna programme began by 1959, with Luna 3 capturing the first images of the Moon's far side. The Apollo 8 crew was the first to see it with human eyes during their historic circumlunar flight in December 1968.

Interestingly, many of the features on the far side of the Moon retain the Russian names given to them by Soviet scientists, contrary to the usual International Astronomical Union naming convention [8]. This unique history adds an extra layer of allure to the exploration of this mysterious hemisphere.

As we continue to unravel the secrets of the Moon's far side, one thing is certain: this enigmatic world has much to teach us about our own planet and the universe beyond. With new missions and technologies on the horizon, the future of lunar exploration is brighter than ever, paving the way for a permanent human presence and a deeper understanding of our cosmic neighbour.

References: 1. https://www.nasa.gov/feature/how-the-moon-was-formed 2. https://www.nasa.gov/feature/lunar-reconnaissance-orbiter-reveals-moon-volcanic-history 3. https://www.lpi.usra.edu/lunar/features/lunar_asymmetry/ 4. https://www.nature.com/articles/nature11709 5. https://www.nature.com/articles/nature16923 6. https://www.nasa.gov/feature/lunar-reconnaissance-orbiter-reveals-moon-volcanic-history 7. https://www.nasa.gov/feature/dark-side-of-the-moon-is-a-misnomer 8. https://www.nasa.gov/feature/lunar-features-names-and-the-international-astronomical-union

Astrophotography and sensitive astronomical observations could benefit significantly from the installation of a radio telescope on the Moon's far side, as its thicker crust provides isolation from electromagnetic interference.
Hypotheses suggest that the Moon's asymmetrical volcanic activity, with less evidence on the far side compared to the near side, may have been influenced by factors such as asymmetric tidal heating and a slow-velocity impact of a second moon.
The science community continues to explore the mysteries hidden within the Moon's far side, with environmental-science, mental-health, and health-and-wellness studies potentially contributing to our understanding of lunar landscapes and their impact on human explorers.
With advancements in space technology and the launch of new missions, the far side of the Moon will likely see an increase in astronauts, impacting not only the realm of space-and-astronomy but also expanding our knowledge in multiple scientific disciplines, including those related to health and sustainability.