Two small Japanese robots landed on a distant asteroid last weekend. The robots took small jumps, making it the first time that any device from our planet has moved on the surface of an asteroid. The two machines, called rovers, landed on the asteroid Ryugu on September 21. The Japan Space Exploration Agency says they were lowered to the surface by an unmanned spacecraft called the Hayabusa2. Asteroids are small, rocky objects orbiting around the Sun. They sometimes have been described as minor planets. The Japanese spacecraft first arrived at Ryugu last June. It flew as close as 55 meters to the asteroid before it released the rovers. Hayabusa2 then rose back up to a waiting position about 20 kilometers above the surface. The next day, Japan’s space agency, known as JAXA, released some pictures the rovers had sent back from the landing area. One shows the dark stone of Ryugu, with a bright line of sunlight lighting up the asteroid’s surface.