BEIJING — The lander and the rover of the Chang’e-4 probe switched to dormant mode for the lunar night on April 12, with the rover traveling an accumulated 178.9 meters on the far side of the moon.

The rover Yutu-2, or Jade Rabbit-2, is expected to awaken again on April 28, and the lander to awaken the following day, according to the Lunar Exploration and Space Program Center of the China National Space Administration.

The Chang’e-4 probe made the first-ever soft-landing on the Von Karman Crater in the South Pole-Aitken Basin on the far side of the moon on Jan 3.

As a result of the tidal locking effect, the moon’s revolution cycle is the same as its rotation cycle, and the same side always faces the Earth.

The far side of the moon was regarded as a virgin territory with unique features, and scientists expect important discoveries.

A lunar day equals 14 days on Earth, and a lunar night is the same length. According to the measurements of Chang’e-4, the temperature of the shallow layer of the lunar soil on the far side of the moon dropped to as low as minus 190 degrees Celsius, lower than data obtained by the US Apollo mission on the near side of the moon.