China’s long-serving Yutu-2 lunar rover has made yet another discovery. This time in the form of several mysterious glass beads. Scientists are hopeful the grape-sized objects contain information about the moon’s history.
It is not particularly difficult to find naturally occurring glass formations here on Earth. The substance is created when silicate minerals are exposed to extreme heat. Silicate (sand) is an incredibly abundant material on Earth, making up roughly 90% of the Earth’s crust.
Examples of these orbs of glass are somewhat commonplace here on Earth. They are often present near the impact sites of sizable meteorite strikes and form when the crust is superheated. The molten beads are quickly cooled in the atmosphere and drop down in the form of a glassy spherule called a tektite.
The area in which Yutu-2 is operating, the Von Kármán crater on the moon’s dark side, is littered with tiny glass beads, most of them measuring no more than a few millimetres in diameter. However, some of the glass spherules identified by China’s Yutu-2 rover’s state-of-the-art panoramic lens have stumped researchers.
Immediately apparent to planetary geologist, Zhiyong Xiao, was the sheer size of the beads Yutu had stumbled upon in the massive lunar crater.
Measuring about 15 to 20mm in diameter, Zhiyong, who works at Sun Yat-sen University and China’s Academy of Sciences, said the beads may have formed during a period of volcanic activity on the moon or as the result of an ancient asteroid strike. According to Science Alert, a digital science publication, Zhiyong speculates it may be the latter.
But it’s not just the size disparity between the beads that have researchers interested. Two examples appear to be translucent or semi-transparent, where smaller, more abundant beads were described as dark and opaque.
The research team has a hunch that given the region they were discovered in, the lunar spherules are indeed tektites, created when volcanic material called anorthosite was superheated during an asteroid strike. If that is the case, the lunar landscape could be scattered by similar structures, offering a unique insight into the moon’s history and composition.
Unfortunately, China’s Yutu-2 rover does not have the necessary tools to perform a detailed analysis or to return a sample to Earth. The hard-working robot has called the moon home for three years, first arriving in early 2019. Zhiyong and his team believe the site could be important for China’s National Space Administration (CNSA) researchers going forward.
Beijing has highlighted space exploration as an area of strategic importance in its previous five-year plan. In 2020 CNSA had a budget of $8.9 billion, second only to the US’ program, NASA.