Official Chinese media confirmed that the nation’s robotic Chang’e-4 probe made the first-ever landing on the far side of the moon — but not before issuing, and then withdrawing, an initial set of announcements.
The honest-to-goodness announcement came via several state-run media outlets just after noon Beijing time on Jan. 3 (8 p.m. PT Jan. 2).
That’s about an hour after the Twitter accounts for China’s CGTV network and the China Daily newspaper flashed word of a landing. Within a minute or two, those tweets were deleted, but the media echoes nevertheless continued through the Twitterverse, mailing lists and online reports.
Those outlets apparently jumped the gun on what was intended to be a coordinated release of the news. In its re-issued announcement, CGTV said the landing took place at 10:26 a.m. Beijing time (6:26 p.m. PT), which meshes with the timing for the initial tweeted-then-deleted reports.
Chang’e-4 is the latest in a series of probes named after the moon goddess in Chinese mythology. The combination lander and rover was sent into space in early December, and followed a slow but efficient 4.5-day trajectory from Earth to the moon. The lander made a series of lunar orbits over the past couple of weeks to line it up for the landing.
Communications were facilitated by a relay satellite that was sent to a gravitational balance point about 33,000 miles beyond the moon last May.
The relay satellite, dubbed Queqiao (“Magpie Bridge,” a name inspired by a Chinese folk tale), is required because there’s never any direct line of transmission between Earth and Chang’e-4. (As even casual skywatchers know, the moon is tidally locked with our planet and always presents its near side to us Earthlings.)
Hours after the landing, the lander deployed its Yutu 2 rover, following the model set five years ago by China’s first robotic lunar landing mission, Chang’e-3. Video and still images were transmitted back to Earth via Queqiao:
— China Xinhua News (@XHNews) January 3, 2019
The lunar rover for China's Chang'e-4 probe was given the name "Yutu-2" (jade rabbit) after making a soft-landing on the far side of the Moon on Thursday, said China's National Space Administration pic.twitter.com/TjG3ONQCvz
— CGTN (@CGTNOfficial) January 3, 2019
The far side was seen by Apollo astronauts, starting with the Apollo 8 crew 50 years ago, and pictures have been captured by a variety of moon-orbiting satellites. NASA’s twin Grail spacecraft crashed on the far side back in 2012. But Chang’e-4 is the first to make a soft far-side landing.
The mission targeted the flat interior of 112-mile-wide Von Karman Crater, which is within the moon’s South Pole-Aitken Basin. The region is thought to have been covered over by lava floods in ancient times, and one of Chang’e-4’s scientific goals is to study the composition of the lunar soil there.
Chang’e-4 will also measure the solar wind, make low-frequency radio astronomy observations and monitor cosmic rays from a side of the moon that doesn’t experience earthly interference. A couple of the probe’s instruments were contributed by teams from Germany and Sweden. Chang’e-4 might also be carrying a “lunar mini-biosphere” with potato seeds, mustard seeds and silkworm eggs.
In a year or so, China is due to launch its Chang’e-5 mission to collect a sample of lunar soil from the Oceanus Procellarum region and return it to Earth.
Chinese space officials have discussed sending crewed missions to the moon in the 2020s or 2030s, and potentially building an outpost near the lunar south pole.
Among those congratulating China’s space feat via Twitter was SpaceX billionaire CEO Elon Musk, who is planning to send Japanese billionaire Yusaku Maezawa and an entourage of artists around the moon in SpaceX’s yet-to-be-built Starship craft during the mid-2020s.
NASA Administrator Jim Bridenstine also sent along his congratulations:
Congratulations to China’s Chang’e-4 team for what appears to be a successful landing on the far side of the Moon. This is a first for humanity and an impressive accomplishment! pic.twitter.com/JfcBVsjRC8
— Jim Bridenstine (@JimBridenstine) January 3, 2019
NASA’s associate administrator for science, Thomas Zurbuchen, said in a follow-up tweet that “we look forward to learning about this rather unexplored part of our moon.”
This is an updated version of a report first published at 8:44 p.m. PT Jan. 2.