A HISTORIC FIRST ON THE FAR SIDE OF THE MOON
China has successfully landed a spacecraft on the moon, announcing its arrival as a bona fide space power
THE PROBE, named Chang’e 4, launched from south-west China last month and which landed at 10.26am (local time) on Wednesday in Von Karman crater within the moon’s South Pole-aitken basin, the largest known impact crater in the solar system.
Shortly after landing, a rover on the landing craft dispatched the first photo of the moon’s surface from its far side back to Earth via a satellite communication relay.
The landing “marked a new chapter in the human race’s lunar and space exploration,” the China National Space Administration (CNSA) said.
“The far side of the moon is a rare, quiet place that is free from interference of radio signals from Earth,” mission spokesperson Yu Guobin said. “This probe can fill the gap of low-frequency observation in radio astronomy and will provide important information for studying the origin of stars and nebula evolution.”
Although China, the US and Russia have operated robotic spacecraft on the moon before, Chang’e 4 is the first to land softly on the side of the satellite that always faces away from the Earth. The geology on this side of the moon is distinctive, with more craters and less evidence of volcanic activity. But it’s difficult to explore because scientists on Earth can’t communicate via radio signal with spacecraft in this remote region – a quandary China’s relay satellite has solved.
The mission transmitted an orangetinted, high-definition photo of the moon’s lightly pockmarked surface.
The landing demonstrated China’s ambitions to become a space power and scientific force in an era when Nasa funding has been shrinking as a percentage of the US federal budget. China spends more on scientific research than any nation but the US, and it launched more rockets than any other country last year.
Last month, China announced it was starting a global service for Beidou – a home-grown satellite navigation system designed to compete with the US Global Positioning System (GPS).
“This is more than just a landing,” said Alan Duffy, a scientist with the Royal Institution of Australia who focuses on space exploration.
“Today’s announcement was a clear statement about the level of maturity that China’s technology has reached. Beijing’s longer-term goal to match US capabilities could become reality within two decades and on the moon within perhaps only one decade.”
China is far from the only nation with its eye on the lunar surface. India, Israel and Germany have lander missions planned for the year, and the Russian and Japanese space agencies aim to send spacecraft to the moon in the early 2020s.
“The whole world is raising their game,” said Maria Zuber, a lunar geophysicist at the Massachusetts Institute of Technology.
In November, Nasa said it would begin contracting with private aerospace companies to send scientific payloads to the lunar surface. The missions could start this year.
Chang’e 4 was the latest in a series aimed at exploring the moon and paving the way for Chinese astronauts to eventually land on the lunar surface. Its predecessor Chang’e 3 delivered a rover called Jade Rabbit to the lunar nearside, where it worked for more than two years. In Chinese mythology, Chang’e is the name of a goddess who lived on the moon.
The Chang’e 4 mission will use its cameras and ground-penetrating radar to understand the composition of the Von Karman crater within the Aitken basin.
There, it’s thought that an ancient meteor impact during the early days of the solar system exposed material from the moon’s deep interior. Obtaining a precise date for the event, and probing the primitive rock it revealed, could help solve lingering mysteries about the formation of the moon and the history of the solar system.
Exploring the Aitken basin has been a priority for the US National Academies of Science, Engineering and Medicine for the past two decades, said Clive Neal, a Notre Dame geologist who is emeritus chair of the US Lunar Exploration Analysis Group. That goal, he said, “has yet to be realised by a Us-led mission”. Still, Zuber said, the Chang’e 4 instrument suite did not include some of the tools required to probe all the questions scientists have.
A spectrometer on the rover will conduct low frequency radio astronomy observations away from the noise of radio networks. The interaction of Earth’s gravity with the moon’s rotation means it faces away from us, making it an ideal site to probe the cosmos without interference.
And the static part of the Chang’e 4 lander carries a small, sealed capsule containing plant seeds and insect eggs. If the delicate cargo can be encouraged to germinate and hatch in the moon’s low gravity, they might form a biosphere – a tiny oasis of life on a cold and airless world.
China’s space programme funding totalled $11 billion in 2017 – compared with $19bn requested by Nasa. The country plans to launch a sample return mission to the moon later this year and has ambitions to crew a lunar base, launch a low-orbit space station and send a probe to Mars by the 2020s.
Nasa administrator Jim Bridenstine congratulated China in a tweet on Wednesday night.
“This is a first for humanity and an impressive accomplishment.”
The official reaction in China was ebullient. The Global Times, a newspaper run by the Communist Party, said China would share the data and pictures it obtained and work with any countries committed to “the peaceful development of space”.
THE FIRST image of the moon’s far side taken by China’s Chang’e-4 probe. | Courtesy of China National Space Administration
AN IMAGE taken by China’s Chang’e-4 probe after its moon landing. National Space Administration | Courtesy of China