BEIJING -- As the Chang'e-4 probe made the first-ever soft landing on the far side of the moon, a senior Chinese space expert said China will deepen its lunar exploration and venture further into the unknown.

China's current lunar program includes three phases: orbiting, landing, and returning. The first two phases have been accomplished, and the next step is to launch the Chang'e-5 probe to collect 2 kg of samples and bring them back to the earth, said Wu Weiren, an academician of the Chinese Academy of Engineering and chief designer of China's lunar exploration program.

There are still many mysteries about the earth's nearest heavenly neighbor and future missions will be more exciting. The program will also promote China as a major player in space exploration.

"We are discussing and drawing up the plan for the fourth phase of the lunar exploration program, including missions to the polar regions of the moon," Wu said.

Some places at the south pole of the moon receive sunlight for over 180 consecutive days, and some areas in craters there are never exposed to sunlight and might hold frozen water, scientists say.

"We hope to build a scientific research station in the south polar region of the moon. It would be operated automatically and visited by people for short periods," Wu envisioned.

China is also planning to launch a probe in 2020 that would orbit, land and rove on Mars the following year.

A heavy-lift carrier rocket, with a takeoff weight of about 4,000 tonnes and a diameter of 10 meters, is a goal for 2030. It would help realize the aim of bringing Mars samples back to the earth and sending Chinese astronauts to the moon.

China is becoming a major player in lunar exploration, and contributing to scientific discovery.

"Exploring the unknown is human nature. The moon is a mysterious world to us. We have a responsibility to explore and to understand it. Exploration of the moon will also deepen our understanding of earth and ourselves," Wu said.