The far side of the moon just had its first man-made visitor.
The China National Space Administration (CNSA) reports that its Chang'e-4 probe touched down on the far side of the moon at 10:26 a.m. Hong Kong time on Jan. 3 (9:26 p.m. ET, Jan. 2) making it the first country to land a craft on this side of the moon.
This, the agency says, will open "a new chapter in human lunar exploration."
The 1.2-ton probe landed near the Von Kármán Crater in the South Pole-Aitken Basin, which is located along the moon's mid-southern latitudes. Not long after it landed, Chang'e-4 transmitted a picture of its landing site. According to CNSA, a rover, named Yutu 2, rolled and began exploring the area in the direction of the crater.
In addition to driving along the moon, the rover will use ground-penetrating radar to map the internal structures of the moon on this side, collect and analyze soil and rock samples and activate a radio telescope to search for signals, the South China Morning Post reports. Also of note is that the probe carries a canister filled with soil, water, air, silkworm eggs, the seeds of a flowering plant and a potato. Scientists hope there will be flowers blooming on the moon within three months.
"China is making a tremendous effort to become a space power. This mission will be a landmark event in this endeavor," Wu Weiren, chief scientist of the Chang'e-4 program, said in an interview with state broadcaster China Central Television.
Since signals from Earth can't directly reach the far side of the moon — and vice versa — communication between CNSA and Chang'e-4 and the rover relies on a relay satellite dubbed Queqiao. The satellite is appropriately named since Queqiao means "bridge of magpies." According to NASA, the name refers to the "to a Chinese folktale about magpies forming a bridge with their wings to allow Zhi Nu, the seventh daughter of the Goddess of Heaven, to reach her husband."
Chang'e-4's soft landing on the moon was not broadcast live during the event but was instead reported only after the successful landing. The agency did release a video of the landing, which was created by combining 3,000 images of the descent and speeding it up.
On Jan. 11, the space agency released this image showing off Chang'e 4. The Yutu 2 rover captured this image, which shows off the lander's low-frequency radio spectrometer and its 16-foot antennae. Change'4 returned the favor and also took an image of its companion.
Why this side of the moon matters
The far side of the moon is often referred to as the "dark side of the moon," but this is a bit of a misnomer. This side of the moon, while it doesn't face the Earth, does receive sunlight. Dark, in this case, just refers to unexplored.
The surface on this side of the moon is "actually much more primitive" than the Earth-facing side, Briorny Horgan, a planetary scientist at Purdue University, told NPR. This intrigues scientists since it has a "really ancient crust that dates back to the very, very early solar system."
"There are rocks all over the far side that are over 4 billion years old," she said. "We're really excited to see what those look like, up close."
The Von Kármán crater where Chang'e-4 landed is the oldest and deepest on the moon, The New York Times reports, and some scientists suspect that the basin surrounding the crater may be rich in valuable minerals. The site could end up being an important one for refueling during space exploration.
China plans to have its third space station up and running by 2022, with astronauts stationed on a lunar base later in that decade as well.
"This is a major achievement technically and symbolically," Namrata Goswami, an independent analyst who wrote about space for the Defense Department's Minerva Research Institute, told The Times. "China views this landing as just a steppingstone, as it also views its future manned lunar landing, since its long-term goal is to colonize the moon and use it as a vast supply of energy."
Editor's note: This article has been updated since it was originally published in January 2019.