One major objective of space exploration is the search for alternative energy sources. And after decades of searching, researchers have found such a source right on our doorstep. As the Chang'e 5 lunar mission nears, CGTN's Wu Lei takes a look at this new potential resource.

WU LEI CGTN reporter "As Earth's supply of coal and oil runs low, humans are now looking to the moon for alternative energy sources. Scientists have found huge amounts of untapped energy in the presence of chemical elements on the moon. The most important of these elements is helium-3, a colorless, odorless, and stable isotope of helium. Scientists say using helium-3 is safer and cleaner, and its non-radioactive. It's estimated that 100 tons of helium 3 would be equivalent to a year's worth of energy consumption on Earth. But the total reserves of helium-3 on Earth only amount to about 500 kilograms. Top Chinese scientist Ouyang Ziyuan has estimated over 1 million tons of helium-3 are embedded in the surface of the moon, which could solve humans' energy demand for roughly 10,000 years. But how can this, and the study of the moon's soil, be explored further? And how does it tie in with China's upcoming lunar mission? Find out more on our next episode."