Read our COVID-19 research and news.

An artist’s impression of the MASCOT rover, which carries a suite of scientific instruments, after today’s landing on Ryugu


Japanese spacecraft drops a third rover on asteroid Ryugu

After successfully dropping two small hopping rovers on the surface of asteroid Ryugu last month, the Japanese spacecraft Hayabusa2 today deployed another probe with a suite of instruments that will do some serious science. Hayabusa2, which arrived at Ryugu in June after a 3.5-year journey, descended to 51 meters above the asteroid and released the Mobile Asteroid Surface Scout (MASCOT). Twenty minutes later, the asteroid’s gravity had pulled the 10-kilogram probe, 30 by 30 by 20 centimeters in size, to the surface.

The Minerva hopping rovers deployed on 21 September have cameras snapping some amazing pictures, but minimal scientific instrumentation. MASCOT, jointly developed by the German Aerospace Center and the French National Centre for Space Studies, carries a camera, instruments to measure day-to-night thermal changes and check for magnetism, and an infrared spectral microscope to study the mineral composition and look for any evidence the asteroid once hosted water or organic molecules. MASCOT will collect data in one location, then hop to a second for another round of observations. About 16 hours after deployment, MASCOT’s batteries will run down and the observation phase of the mission will be over.

A photo MASCOT took as it approached Ryugu was posted on Twitter earlier.

Hayabusa2 itself is likely to make the first of three touchdowns on the asteroid to collect samples later this month. It will start its journey back to Earth in late 2019.