Earlier this month, scientists did something they've never done before: they successfully landed rovers on an asteroid!

The two rovers, which landed Friday, Sept. 21, are each the size of a wheel of cheese and are designed to hop along the surface of the asteroid Ryugu, taking pictures and collecting information. The reason they hop rather than drive has to do with the fact that since Ryugu is only half a mile in diameter, the gravity is very low. That makes it very difficult to stay on the surface and drive like other rovers can on Mars, for example.

This mission is part of a 1.5-year-long MINERVA-II1 program from the Japan Aerospace Exploration Agency (JAXA). The spacecraft that transported the two rovers is called Hayabusa2 and is on an asteroid sample-return mission. That’s right – one of the goals of this mission is to return samples of the Ryugu asteroid back to Earth! Ryugu is a certain type of asteroid that scientists think have organic or hydrated (have lots of water) minerals, and may have contributed to the existence of life on Earth.

Normally, Hayabusa2 orbits the asteroid from 12.5 miles away. On Sept. 21, it lowered down to just 180 feet above the surface to safely drop the two rovers before retreating back to its normal distance. In October, Hayabusa2 is expected to drop an even larger rover, MASCOT, and another tiny hopping rover next year.

Interested in learning more? We're currently covering this topic in our all-live planetarium show, "Wonders of the Night Sky," as part of our LSC Space News Now breaking news portion. Click here to see our full list of shows in the Jennifer Chalsty Planetarium, the biggest planetarium in the Western Hemisphere.