A Chinese probe called Chang’e 4 recently made history: It became the first spacecraft to land on the moon’s unexplored far side. The moon rotates on its axis at the same speed as it orbits Earth. So its far side always faces away from our planet.
Chang’e 4 is outfitted with cameras, scientific instruments, and a small six-wheeled rover it deployed on the lunar surface. The probe will use these tools to explore a 13 kilometer (8.1 mile)-deep crater. Scientists believe the crater formed when a space rock smashed into the moon more than 3 billion years ago. The ancient collision likely exposed some of the moon’s mantle, or layer just beneath its outer crust. By studying the crater, scientists will learn more about the geologic history of the moon.
Chang’e 4 also carries a small sealed container holding water, soil, air, a heating system, and the seeds of several types of plants. This biosphere will help scientists study whether life can thrive in the moon’s low-gravity environment. Researchers celebrated when cotton seeds in the biosphere sprouted—becoming the first plants to grow on the moon. Unfortunately, the plants froze when the probe entered a planned shutdown, which shut off its heat supply. The cotton couldn’t withstand the moon’s freezing temperatures.