After arriving at asteroid Ryugu on June 27 of last year (2018), Hayabusa2 spent all its time exploring the small celestial body. Then on November 13, 2019 at 10:05 JST (onboard time), the spacecraft left Ryugu to return home. In total, Hayabusa2 had stayed at Ryugu for 504 days.

From November 13 to 19, the “Ryugu Farewell Observation” was performed. On November 19, the attitude of the spacecraft was changed to that needed for the ion engine injection, making it no longer possible to photograph Ryugu.

This image (Figure 1) was captured with the ONC-T (Optical Navigation Camera – Telescopic) during the “Ryugu Farewell Observation” and was posted on our twitter feed on November 21.

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  Figure 1: Animation created from navigation images captured during the departure from Ryugu from November 13, 2019 until the disappearance of Ryugu due to attitude control on November 19, 2019. This image was previously released on November 21. Image frames are not continuous in time. (Image credit※: JAXA, Chiba Institute of Technology, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, University of Aizu, AIST).

When Figure 1 was released, only a subset of our final images of Ryugu had been downloaded to Earth. Later we acquired all the images from the spacecraft. Figure 2 shows the full version of this animation, with images captured by ONC-T and ONC-W1 (Optical Navigation Camera – Wide angle).

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  Figure 2: Animation created from a continuous set of navigation images captured during the departure from Ryugu from November 13, 2019 until the disappearance of Ryugu due to attitude control on November 19, 2019. ONC-T images are on the left and those from ONC-W1 are on the right. (Image credit※: JAXA, Chiba Institute of Technology, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, University of Aizu, AIST).

In Figure 2, the position of Ryugu occasionally shifts suddenly due to the spacecraft changing its attitude. This attitude adjustment was done so that Ryugu does not leave the camera’s field of view. Then on November 19, Ryugu did move out of the camera’s field of view due to the necessary attitude control for ion engine operations.

After watching for nearly one year and five months, it feels lonely now that Ryugu has disappeared. But our departure was needed for the last important task: the return to Earth.

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  The Project members say goodbye to Ryugu. Image taken on November 13, 2019 (image credit: JAXA).

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  Our Ryugu-no-tsukai (Japanese oarfish) in the control room, who watched all the operations while staying at Ryugu (?). Ryugu-no-tsukai is expressing all our feelings by announcing he is “Extremely thankful”. Image taken on November 13, 2019 (image credit: JAXA).

Hayabusa2 Project
2019.12.28

※ Please use the displayed credit when reproducing these images. In the case where an abbreviated form is necessary, please write "JAXA, Chiba Institute of Technology & collaborators".