From the far side, scientists may eventually be able to peer back to 50 million to 100 million years after the Big Bang, when the first stars were born - or even earlier, he said.
Chang'e 4 had touched down on the surface at 10:26 a.m., the China National Space Administration said. Chang'e is the name of a Chinese goddess who, according to legend, has lived on the moon for millennia.
This isn't a coincidence: Tidal forces from Earth have slowed down the Moon's rotation to the point where the same side is always facing the Earth - a phenomenon called tidal locking.
The spacecraft, which blasted off into the heavens on December 7, was in an elliptical orbit around the Moon, swinging within 15 kilometres (nine miles) of the lunar regolith. Radio waves from Earth can not reach the far side back of the moon, so Change 4's link to the flight control centre in Beijing is dependent entirely on a small, distant relaying satellite called Queqiao. At the height of day, temperatures can hit around 260 dehrees Fahrenheit, but plummet to around -280 Fahrenheit at night.
They may find minerals and other chemicals that tell us more about the origins of the moon, and which could also increase the likelihood of future mining missions. The first human-made object to hit the dark side of the moon was NASA's Ranger 4 craft in 1964, which crashed after a system failure. For example, the chemical and mineralogicial analyses of the rocks will be pretty basic. That was a test run for the Chang'e 5 sample-return effort, which could launch as early as this year.
China launched a ground-breaking mission to soft-land a spacecraft on the largely unexplored far side of the moon, demonstrating its growing ambitions as a space power to rival Russian Federation, the European Union and US.
The project is the latest chapter in Beijing's billion-dollar space program.
Soon-if not already-the lander will deploy a rover named Yutu II (Jade Rabbit II).
Worldwide treaties stipulate that space is free for all nations to explore and no country can make a sovereign claim on the moon, even if they plant a flag.
However, while China has insisted its ambitions are purely peaceful, U.S. officials have accused it of pursuing activities aimed at preventing other nations from using space-based assets during a crisis.
China has two space stations in orbit and plans to launch a Mars exploration vehicle in the mid-2020s.
"Chang'e-4 is humanity's first probe to land on and explore the far side of the moon", said the mission's chief commander He Rongwei of China Aerospace Science and Technology Corp, the main state-owned space contractor.
This article has been updated with background information and comment from David Rothery.