The Images of asteroid Ryugu taken from an altitude of 1 km

Arriving on June 27, and after a voyage of 3½ years, the spacecraft Hayabusa 2 has gotten to what will be its home for the next 18 months, asteroid Ryugu, small and strange in shape, the spacecraft dropped to about 6 km between July 20 to 21. Next on August 1, Hayabusa 2 remained at an average altitude of 5 km commencing the third phase of the descent operation on August 6 to measure its gravity. 

This gravity measurement operation consisted in the no control of the craft and letting Ryugu attract it, without Earth control, (freefall, free ascent). Doing this, it was possible to appreciate the movement of the spacecraft, and test how string is the gravity of the asteroid. 

Hayabusa's path to Ryugu, based on the 2015 Earth flyby. JAXA

The spacecraft began its descent from the initial position (distance from the Ryugu was of 20 km from the surface of the asteroid) before August 6 at 11:00 (Japan time). Approximately at 20:30 on the same day, the altitude reached 6,000 m and from there it started the free fall. After, it got at the minimum distance of 851 m at around 8:10 on August 7, when it started to use its thruster to rise up. 

Now, the Japanese Space Agency JAXA, has shown us this spectacular close up images of this small and strange celestial body. This small space rock was discovered by the Lincoln Near-Earth Asteroid Research (LINEAR) survey on the night of May 10, 1999, and provisionally designated 1999 JU3 before receiving a number and being renamed Ryugu (“Dragon's Palace” from a Japanese folktale) in late 2015. 

Ryugu is an Apollo-group asteroid, dubbed "potentially hazardous" because it has the potential of passing very close to Earth, as close to Earth as 95.400 km, about a fifth of the Moon's distance. On the short term it will not be dangerous, for the closet it will be to us occurs on December 2076, as close as four times the Earth-Moon distance. 

Touchdown. An artist's conception of Hayabusa 2 sampling asteroid Ryugu. JAXA

Hayabusa 2 will commence it final approximation at the end of September or October, touching the asteroid and doing the first of the three sampling operations. Later, at the end of next year, in November of December, it will leave the asteroid to deliver its capsule sample return to Earth by December 2020. 

Figure 1 and Figure 2 shows the pictures taken with the telephoto optical navigation camera (ONC-T) before the minimum altitude reach.

Figure 1 (a) 

Figure 1 (b) 

Fig. 1 Surface of Ryugu from about 1250 m taken with telephoto optical navigation camera (ONC-T). 8/7/2018 and shoot at 7:37 (Japan time). All the pictures were taken almost at the same time with the with the wide angle optical navigation camera (ONC-W). the red box corresponds to the ONC-T shooting range. Image credit note: JAXA, Tokyo University, Kochi University, Rikkyo University, Nagoya University, Chiba Institute of technology, Meiji University, Aizu, AIST

Figure 2 (a) 

Figure 2 (b) 

Fig. 2 The surface Ryugu taken with the telephoto optical navigation camera (ONC-T) from about 1000 m. 8/7/2018 and shoot at 7:57 (Japan time). Todas las imágenes de Ryuguu fueron tomadas casi al mismo tiempo por la cámara de navegación óptica gran angular (ONC - W). El marco rojo corresponde al rango de fotografía de ONC-T. Crédito de la imagen: JAXA, Universidad de Tokio, Universidad de Kochi, Universidad de Rikkyo, Universidad de Nagoya, Instituto de Tecnología de Chiba, Universidad Meiji, Universidad de Aizu, AIST

Fuentes: JAXA, skyandtelescope, Wikipedia,