Hayabusa2 Samples an Asteroid

Asteroid 162173 RyuguOn February 22, 2019, the Japan Aerospace Exploration Agency (JAXA) space probe Hayabusa2 (はやぶさ2) which has been exploring the small near-Earth asteroid 162173 Ryugu since its arrival on June 27, 2018, descended to the surface and collected a sample of the surface, which will be stored for eventual return to Earth. Here is a video of the descent, with material thrown up by the thrusters for collection.  The video is sped up by a factor of five.  Note the shadow of the spacecraft on the asteroid’s surface.

Ryugu is a very small asteroid, around 1 kilometre in diameter, discovered in 1999 by a search for near-Earth asteroids.  It is a rare type Cg asteroid, which combines characteristics of types C and G.  Such objects are rich in carbon compounds and very dark: its geometric albedo is between 0.044 and 0.050, reflecting around one third as much light as the Earth’s moon—Ryugu is comparable to a lump of coal.  Surface gravity on Ryugu is 0.00011 metres per second², 1/80,000th Earth’s gravity.

The video was taken by a camera called CAM-H, which was funded by a public subscription campaign.

In April 2019, Hayabusa2 will fire an explosively-formed projectile into the asteroid to sample sub-surface material.  As that is expected to be a very “dynamic” event, the spacecraft will hide on the other side of the asteroid when the projectile is fired: a free-flying camera is planned to image the impact.  The plan is to continue to investigate Ryugu until December 2019, when the spacecraft will depart to return the collected sample to Earth, landing its sample return capsule at the Woomera Test Range in Australia in December 2020.

Here is a Scott Manley video describing the mission.


Author: John Walker

Founder of Ratburger.org, Autodesk, Inc., and Marinchip Systems. Author of The Hacker's Diet. Creator of www.fourmilab.ch.

4 thoughts on “Hayabusa2 Samples an Asteroid”

  1. On April 5th at 02:36 UTC, Hayabusa2 plans to fire its copper impactor into asteroid 162173 Ryugu.  The impactor will hit at a speed of 2 km/second and make a small crater, while the main spacecraft is hiding on the other side of the asteroid.  It will then emerge and fly through the debris cloud, hoping to collect samples of sub-surface material which has not been subjected to radiation and baking from the Sun.

    JAXA will broadcast a live Webcast of the event from their control centre, with English subtitles.  The Webcast is scheduled to go live at 01:15 UTC.  Ruygu is presently around 20 light minutes from Earth, so information will arrive that interval after events on the asteroid.  Here is a complete timeline from JAXA.


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