A Japanese probe launched a new observation robot towards an asteroid on Wednesday as it pursues a mission to shed light on the origins of the solar system.
The Hayabusa2 probe launched the French-German Mobile Asteroid Surface Scout, or MASCOT, towards the Ryugu asteroid's surface, the Japan Aerospace Exploration Agency (JAXA) said.
"We can confirm that the MASCOT separated from the spacecraft as planned," the agency said in a tweet on its official account.
It was not clear how long it would take for confirmation of the robot's safe landing on the asteroid, where it is expected to collect a wide range of data.
"It is hugely significant to take data from the surface of an asteroid, we have high expectations for the scientific data," Hayabusa2 mission manager Makoto Yoshikawa said at a briefing before the landing.
The 10-kilogramme (22-pound) box-shaped MASCOT is loaded with sensors. It can take images at multiple wavelengths, investigate minerals with a microscope, gauge surface temperatures and measure magnetic fields.
MASCOT's launch comes 10 days after the Hayabusa2 dropped a pair of MINERVA-II micro-rovers on the Ryugu asteroid -- a world first.
Unlike those machines, MASCOT will be largely immobile -- it will "jump" just once on its mission, and it can turn on its sides.
And while the rovers will spend several months on the asteroid, the MASCOT has a maximum battery life of just 16 hours, and will transmit the data it collects to the Hayabusa2 before running out of juice.
The Hayabusa2 is scheduled later this month to deploy an "impactor" that will explode above the asteroid, shooting a two-kilo (four-pound) copper object into it to blast a small crater on the surface.
The probe will then hover over the artificial crater and collect samples using an extended arm.
The samples of "fresh" materials, unexposed to millennia of wind and radiation, could help answer some fundamental questions about life and the universe, including whether elements from space helped give rise to life on Earth.
Hayabusa2, about the size of a large fridge and equipped with solar panels, is the successor to JAXA's first asteroid explorer, Hayabusa -- Japanese for falcon.
That probe returned from a smaller, potato-shaped, asteroid in 2010 with dust samples despite various setbacks during an epic seven-year odyssey and was hailed as a scientific triumph.
The Hayabusa2 mission was launched in December 2014 and will return to Earth with its samples in 2020.