China wants to explore the Moon, especially its far side. But, why?

Helium-3, which exists in abundance on the Moon, could potentially solve energy demands on Earth for 10,000 years

China's Chang'e-4 lunar probe, which this week landed on the far side of the Moon - a world first - has certainly caught global headlines.

And, coming next in the Chinese Lunar Exploration Program, will be missions in which probes will take rock samples from the surface of the Moon and return to Earth with them for laboratory analysis.

But with the attention of NASA and people like Elon Musk focused on Mars - and beyond - the question is why the focus on the Moon by the China National Space Administration (CNSA)?

For China, the Chang'e-4 mission is partly an attempt to catch up with the US and Russia, and for the nation's ambitious government to make it a major space power within the next 10 years.

Up until now, only a handful of Americans have set foot on the Moon, but China can now claim that its scientists have achieved something that no other country has done so far.

Scientists believe Helium-3 could be used as a fuel in controlled thermonuclear fusion reactors

The rover launched from the Chang'e-4 probe will explore the Moon's crust and mantle on its far side and is likely to come up with some new scientific information. Also included on the craft is an experiment involving seed potatoes and arabidopsis plant seeds, devised by scientists at 28 universities in China.

"We want to study the respiration of the seeds and the photosynthesis on the Moon," Liu Hanlong, chief director of the experiment and vice president of Chongqing University, told the Xinhua news agency in April 2018.

The seeds will be grown in a 'lunar mini biosphere' in an experiment intended to see how easy - or otherwise - it might be to grow crops elsewhere in the Solar System.

"We have to keep the temperature in the 'mini biosphere' within a range from one degree to 30 degrees, and properly control the humidity and nutrition. We will use a tube to direct the natural light on the surface of Moon into the tin to make the plants grow," added Xie Gengxin, chief designer of the experiment, in the Xinhua report.

Moon mining

The dark side of the Moon, which is never seen from Earth, has a thicker crust and is more heavily cratered than the side of the Moon that can be seen from Earth.

And CNSA has other plans for future missions that will not only involve analysing the surface and upper sub-surface of the Moon but also taking back rock samples - the first such mission since the Soviet Union's unmanned Luna 24 mission in 1976.

Scientists believe the Moon is rich in natural resources, including rare earth elements - a market on Earth that China's government has sought to corner - as well as uranium and titanium.

Helium-3 is another important element that is rarely found on Earth but is abundant on the Moon. Helium-3 is an isotope which is emitted by the Sun and spread throughout the Solar System by solar winds. However, it is repelled by the Earth's magnetic field, and only a small amount of it ever reaches the surface of the Earth.

The Moon has a weak magnetic field and a thin atmosphere, meaning significant amount of Helium-3 can penetrate through its atmosphere to be deposited on the surface.

The Moon's Helium-3 resources could solve energy demand on Earth for about 10,000 years

Scientists believe Helium-3 could be used as a fuel in controlled thermonuclear fusion reactors and potentially solve energy demands on Earth. Scientists are currently working to develop such reactors and hope to come up with a functional prototype in near future.

It is estimated that just eight tons of Helium-3 in fusion reactors would be able to provide equivalent energy produced by the burning of about one billion tonnes of coal in a thermal power plant. In 2013, Chinese scientist Ouyang Ziyuan said that the Moon's Helium-3 resources could solve energy demand on Earth for about 10,000 years.

China selected the Von Karmen crater as the landing site for its lunar probe, experts believe, to find minerals and other chemicals at this site with the aim in the future of conducting mining missions.

CNSA's follow-up mission, Chang'e-5, is scheduled for in 2019. It is intended to land at the Mons Rümker region of Oceanus Procellarum, "and return a 2 kg sample of lunar regolith, possibly from as deep as 2 meters", according to a NASA report.

However, it won't be until 2036 until a Chinese flag is planted by a human being on any part of the Moon's surface, according to current schedules, and mining for minerals will almost certainly take a lot longer than that.