Our Moon is two-faced. Science missions unravel its layers.

It wasn’t until 1959 that any being on Earth saw our Moon’s farside for the first time. Because the Moon is tidally locked to Earth, we only ever see its familiar nearside face. In the early days of space exploration, the Soviet Luna 3 and spacecraft succeeding it transmitted the first lunar farside images. While these captured images at low resolutions by today’s standards, the photos nevertheless revealed a far more cratered hemisphere than the Moon’s nearside. It looked more akin to Mercury and Jupiter’s moon Callisto than the gray world in our skies. The Moon’s farside also lacks its nearside’s familiar dark splotches, volcanic plains formed about 3 to 4 billion years ago. To this day, scientists don’t know exactly why our Moon has two distinct hemispheres.Our Moon’s nearside and farside. The farside is more cratered and lacks dark plains which are abundant on the nearside. Images: NASA / LRO / ASU | Graphic: Jatan MehtaObservations by more spacecraft later on only deepened the…