An artist's illustration of the Chang’e 5 spacecraft, which retrieved lunar rock samples (Credit: CNSA)

China’s Chang’e 5 spacecraft, tasked with bringing lunar rock samples to Earth, successfully landed on the Moon on December 1st, 2020. The 18,100-pound (8,200 kg) spacecraft, launched from China’s Wenchang Spacecraft Launch Site on November 23, 2020, entered the satellite's orbit on November 28th, 2020. Soon after, it deployed its lander and ascender modules to the Mons Rümker, an isolated volcanic formation on the Moon's near side.

Within 19 hours of landing, the probe gathered about 4.4 lbs (2 kg) of rocks and soil by drilling almost 6.5 feet (2 meters) deep into the lunar surface using its robotic arm. The sample-filled jar was placed in the ascender vehicle, which left the Moon's surface and entered the lunar orbit on December 3rd, 2020. Then, in a historic first, the ascender and Chang’e 5 orbiter spacecraft successfully came together on December 6, 2020, (Beijing time) to complete the first-ever robotic rendezvous and docking in lunar orbit.

"In terms of the space tasks that humans have performed so far, only the Apollo program missions have completed the rendezvous and docking in lunar orbit. However, uncrewed rendezvous and docking have never been done before," Peng Jing, deputy chief designer of the Chang'e 5 probe from the China Academy of Space Technology (CAST), told Chinese media ahead of the attempt.

With the rock samples safely transferred to the return capsule, the Chang'e 5 spacecraft will continue to circle the Moon for a few days before beginning its 112-hour journey back to Earth. The spacecraft is expected to land in the Ulanqab region of Inner Mongolia, China, on December 16th or 17th, 2020.

If all goes as anticipated, China will become the third country, after the US and Russia, to successfully retrieve lunar rocks. More importantly, the 1.2 billion-year-old samples will be the youngest-ever obtained from the satellite. The pristine space souvenirs, the first collected in 44 years, could give scientists a better understanding of the Moon's formation and provide important insights into how Earth and the solar system evolved.

China is not the only country on a quest to collect space rocks. On December 6, 2020, Japan's $250 million Hayabusa2 mission returned to Earth carrying pieces from a near-earth asteroid called Ryugu. The capsule's contents will allow researchers to better understand the origins of the solar system and, possibly, life on our planet.

Resources: physicsworld.com, earthsky.com, physicsworld.com,earthsky.com