China launched its Chang'e-4 rover and lander today, which if all goes well, will land on the far side of the moon in the coming weeks. It will be the first surface mission to land on that side of the moon, which can't be seen from Earth. While China hasn't shared a lot of information about the mission, a study published earlier this year has given us a look at what's likely in store, and if successful, the mission will help us understand this little-studied side of the moon and provide insight into some of the differences known to exist between the two sides.
According to the study, the lander will target the large Von Kármán crater, and once it has landed, it and the rover on board will analyze the moon's soil, study its subsurface structure and probe the solar wind. China's state-run news agency Xinhua News also reported in April that Chang'e-4 will carry seeds and possibly silkworm eggs to see how both fare on the moon. "It's going to a place that is really special for lunar science," University of Manchester researcher Katherine Joy told The Guardian. "The impact crater carved a huge hole in the lunar crust and possibly into the lunar mantle. It potentially unlocks rocks that we wouldn't normally find on the surface of the moon."
Researchers are also planning to conduct a radio-astronomical study. Since the far side of the moon is blocked off from Earth, radio noise coming off of Earth is blocked as well. And that means telescopes stationed on the far side of the moon could be poised to pick up signals that are hard to detect here on Earth. "Astronomers have long dreamed of a radio telescope array built on the far side of the moon," Tamela Maciel, the space communications manager at the UK's National Space Centre, told The Guardian. She said stationing a telescope there "would be like escaping from city light pollution and seeing the night sky from the top of a mountain. With a radio telescope on the far side of the moon, we would be able to explore the furthest and oldest objects in the universe like never before."
Chang'e-4 launched aboard a Long March 3B rocket around 1:22PM Eastern from the Xichang Satellite Launch Center. While an official feed of the launch wasn't provided, unofficial channels offered streams that showed a successful liftoff. Xinhua News has since confirmed the launch and others have reported it to be a success.
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Chang'e-4 follows three other successful missions of the Chang'e program. The first two involved probes that were put into orbit around the moon, while the Chang'e-3 mission put a lander and rover on the near side of the moon. Upcoming missions making up the program's third phase will aim to collect lunar samples and return them to Earth.
China hasn't said when we can expect Chang'e-4 to land, but many predict it will happen during the first week of January. The equipment will communicate with Earth via a satellite launched earlier this year specifically for this mission that's currently in a high orbit around the moon.