The spacecraft Hayabusa 2 casts a shadow on the asteroid Ryugu as it approaches to deploy two rovers on the surface of the tiny space rock. Photo / JAXA
On a primitive piece of space rock more than 100 million miles from Earth, two tiny robotic explorers took their first cautious "hops" this weekend - the first movements made by any human-made spacecraft across the surface of an asteroid.
The twin rovers were deposited Friday atop the half-mile-wide asteroid
Ryugu by their parent spacecraft, the Japanese Space Agency's Hayabusa 2. The following day, JAXA shared an impressionistic image of their landing site: the craggy dark stone of the carbon-rich Ryugu lit by a brilliant beam of light from the sun.
The rovers, dubbed MINERVA-II 1a and 1b, are each roughly the size and shape of a cookie tin. Solar-powered internal rotors loft them in the asteroid's low gravity, allowing them to propel themselves across its surface to snap photographs and take temperature data.
"I cannot find words to express how happy I am," project manager Yuichi Tsuda said in a statement after the rovers' safe arrival was confirmed.
In the coming months, the MINERVA-II rovers will be joined by two more landers. Hayabusa 2 will also smash the asteroid with explosives to blast away part of its surface, exposing underground material that the spacecraft will then collect and eventually send back to Earth. If all goes to plan, it will be the first mission to return a sample from a C-type asteroid, which are often compared to time capsules from the earliest days of the solar system, more than 4 billion years ago.
