China's Yutu-2 rover spots two intact spheres of translucent GLASS on the far side of the moon that likely formed during lunar meteorite impacts
China's Yutu-2 rover has spotted two intact spheres of translucent glass up to an inch thick on the far side of the moon.
Images returned by the rover, which landed on the moon in January 2019, show the glass globules looking like a couple of tiny ball bearings. Small glass 'spherules' are actually common on the moon, although they're typically less than 0.03 of an inch (3mm) in diameter.
These newly-found glass spheres are much bigger, measuring around 0.5-inch to 1-inch (1.5 cm to 2.5 cm), according to the scientists.
Glass forms on the moon when silicate material – rock-forming minerals – are subjected to high temperatures.
It's known that volcanic glass deposits were formed during explosive eruptions in the moon's history, when it was volcanically active.
Today, new glass can be formed on the moon due to the heat generated from impacts by meteorites with the lunar surface.
Pictured are the centimeter-sized glass globules collected by the Apollo 16 missions (a, b) and those observed by Yutu-2 (c, d)
Images returned by the rover show the glass globules looking like a couple of tiny ball bearings
'Transparent and translucent glasses on the Moon are less than 1 mm in diameters, and larger ones are dark and opaque,' they say.
'The globules were formed or exposed recently as evidenced by their intact shapes and surface exposure.'
Exact composition of the glass is yet to be determined, however.
'Glass is ubiquitous in lunar regolith, and volcanism and hypervelocity impacts are the major mechanisms of forming lunar glasses,' the team say.
'Volcanic glasses on the Moon occur as quenched skin of basaltic rocks or as glass spherules in pyroclastic deposits.'
Volcanic glasses were returned by NASA's Apollo missions in the late 1960s and early 1970s, although some of these were darker and larger than the spotted specimens – up to 1.5 inches thick.
This is not the first time Yutu-2 has come across odd lunar features – last year, it returned photos of a 'mystery hut' in the horizon, which researchers initially had trouble identifying.
On closer inspection, it was revealed in January that it was a rabbit-shaped rock, surrounded by its own rocky 'droppings' and morsels of food.
Images show the locations of glass globules along the Yutu-2 rover path on the moon. (a) Red dot marks the location of the Chang'e-4 mission to the moon (which included Yutu-2). (b) Route of the Yutu-2 rover before July 2020, and the landing site is marked in red. Tips of the green arrows point to the locations of the confirmed and possible glass globules
Volcanic glasses were returned by NASA's Apollo missions in the late 1960s and early 1970s. Here, lunar volcanic glasses are displayed at the Natural History Museum in Vienna from the Apollo 15 mission in 1971
In February 2021, Yutu-2 captured images of an elongated 'milestone' rock on the lunar surface.
The moon rover spotted the sharp structure sticking out from the ground after awakening from a 14-day slumber during the dangerously cold lunar night.
Because Yutu-2 is solar-powered, it constantly has to keep 'going to sleep' when there's no sunlight, during the 14-day long lunar night.
In 2019, just months after it landed, Yutu-2 found a mysterious 'gel-like' substance of a dark green colour.
Yutu-2 has been traversing the 115-mile-wide (186km) Von Kármán crater ever since it landed on the moon attached to the Chang'e-4 spacecraft on January 3, 2019.
Chang'e 4 was China's fourth mission to the moon and the second to send a rover.
Glass is ubiquitous in lunar regolith - the dusty blanket of sediment on the moon's surface, according to scientists
The Yutu 2 rover (pictured) became the first spacecraft to land on the dark side of the moon in January 2019
The Chang'e 1 and 2 missions were orbiters, while Chang'e 3 landed on the near side of the moon with the first Yutu rover.
Beijing also launched Chang'e-5 in November 2020, which successfully returned the first moon samples to Earth in more than 40 years.
China has also just approved three more missions to the Moon – Chang'e 6, 7 and 8 – launching from 2024 onwards.
China's Yutu 2 team said an oddly-shaped rock looks like a small but 'lifelike' crouching bunny like a statue set in stone, surrounded by its own rocky 'droppings' and morsels of food
NASA, meanwhile, is gearing up to send humans to the moon 'no earlier than 2025', as part of its Artemis mission, a follow-up to the Apollo missions.
The Artemis mission will be the first to land humans on the moon since Apollo 17 in December 1972.
NASA is also working on a project to build the first lunar space station, codenamed the Lunar Gateway, as part of a long-term project to send humans to Mars.
NASA will land the first woman and first person of color on the moon in 2025 as part of the Artemis mission
Artemis was the twin sister of Apollo and goddess of the moon in Greek mythology.
NASA has chosen her to personify its path back to the moon, which will see astronauts return to the lunar surface by 2025 - including the first woman and the next man.
Artemis 1, formerly Exploration Mission-1, is the first in a series of increasingly complex missions that will enable human exploration to the moon and Mars.
Artemis 1 will be the first integrated flight test of NASA’s deep space exploration system: the Orion spacecraft, Space Launch System (SLS) rocket and the ground systems at Kennedy Space Center in Cape Canaveral, Florida.
Artemis 1 will be an uncrewed flight that will provide a foundation for human deep space exploration, and demonstrate our commitment and capability to extend human existence to the moon and beyond.
During this flight, the spacecraft will launch on the most powerful rocket in the world and fly farther than any spacecraft built for humans has ever flown.
It will travel 280,000 miles (450,600 km) from Earth, thousands of miles beyond the moon over the course of about a three-week mission.
Artemis 1, formerly Exploration Mission-1, is the first in a series of increasingly complex missions that will enable human exploration to the moon and Mars. This graphic explains the various stages of the mission
Orion will stay in space longer than any ship for astronauts has done without docking to a space station and return home faster and hotter than ever before.
With this first exploration mission, NASA is leading the next steps of human exploration into deep space where astronauts will build and begin testing the systems near the moon needed for lunar surface missions and exploration to other destinations farther from Earth, including Mars.
The will take crew on a different trajectory and test Orion’s critical systems with humans aboard.
Together, Orion, SLS and the ground systems at Kennedy will be able to meet the most challenging crew and cargo mission needs in deep space.
Eventually NASA seeks to establish a sustainable human presence on the moon by 2028 as a result of the Artemis mission.
The space agency hopes this colony will uncover new scientific discoveries, demonstrate new technological advancements and lay the foundation for private companies to build a lunar economy.
