A pair of mysterious glass balls have been discovered on the surface of the Moon by China’s lunar rover.
The semi-transparent spheres measure up to four centimeters across and were captured by Yutu-2’s panoramic camera.
According to a study published Tuesday, the bizarre objects are located on the Moon’s far side, which Yutu-2 has been exploring since 2019.
Unfortunately, the washing machine-sized robot was unable to analyze the chemical makeup of the “spherules”.
They’ve been earmarked as targets for further study as they could help shed light on the Moon’s early history.
Small glass spheres are a relatively common sight on the moon, although they’re typically less than three millimeters in diameter.
They’re created when silicate material is subjected to very high temperatures – both of which are readily available on the moon.
Typically, spherules are leftovers from when the Moon was volcanically active or are created by meteorite impacts.
The extreme heat generated by the latter was most likely responsible for the balls found by Yutu-2.
“Transparent and translucent glasses on the Moon are less than 1 mm in diameters, and larger ones are dark and opaque,” researchers write.
“The globules were formed or exposed recently as evidenced by their intact shapes and surface exposure.”
Further study of the spherules could uncover new information about the composition of the Moon’s mantle and impact events.
The research was published in the journal Science Bulletin.
Yutu 2 has traveled a full kilometer since landing on the far side of the Moon in early 2019.
It celebrated three years of exploring the rocky satellite’s far side – the first rover to do so in history – on Jan. 11.
It’s not the first curious discovery that Yutu-2 has made.
In December, China’s space agency shared an image of a “mysterious house” captured by the rover on the far side of the lunar surface.
The cube-shaped object stuck out from the lunar horizon near the Von Kármán crater in the South Pole-Aitken Basin.
Scientists couldn’t agree on what it was, while online conspiracy theorists were adamant that it was a structure built by aliens.
It took Yutu-2 a few weeks to close in on the object and snap a better image. Experts eventually concluded it was an oddly-shaped rock.
This article originally appeared on The Sun and was reproduced here with permission.