Located near Bennu’s equator, site Osprey is set in a small crater with a 33 ft (10 m) radius. Osprey was selected as the backup sample collection site over sites Sandpiper and Kingfisher because it has fewer hazards, it’s easier to navigate the spacecraft in and out of, and it appears to contain relatively more fine-grained material. Osprey's sampling region has a 16 ft (5 m) radius. Given Osprey’s geographical position on Bennu’s equatorial bulge, it is possible that the region contains material from both the northern and southern hemispheres. Osprey has the strongest spectral signature for carbon-rich material among the four sites. A large, dark (low albedo) patch of material in the center of the site is of high scientific interest for the mission team.
Reconnaissance A Imagery
This is the highest-resolution image captured of candidate sample site Osprey as of October 12. Site Osprey is located near asteroid Bennu’s equator in the northern hemisphere. Because the region of interest is so large, only a portion of the crater is shown in this image. Site Osprey’s recognizable features are visible – there is a dark patch of material in the center of the crater, and a large, flat boulder on the northern crater wall (upper left). The image was taken by the PolyCam camera on NASA’s OSIRIS-REx spacecraft on October 12, from a distance of 0.6 miles (1 km). The field of view is 47 ft (14.2 m). For reference, the fracture in the large boulder (upper left) is 10 ft (3 m) long, which is about the length of a standing grizzly bear. The image was obtained during the mission’s Reconnaissance A phase. When the image was taken, the spacecraft was over the northern hemisphere, pointing PolyCam south and to the west.
Digital Terrain Model
This 3D printed model showcases Osprey’s “12 o’clock rock” and the crater floor’s topography. The crater is 66 ft (20 m) in diameter, which is about the length of a bowling lane.
Credit: NASA/Goddard/University of Arizona/CSA/York/MDA
This set of stereoscopic images provides a 3D view of site Osprey, located in Bennu’s northern hemisphere. The two images in this stereo pair were taken from slightly different viewpoints, with one of the images meant for the left eye and the other for the right. The two images are then combined by the brain to give the perception of depth. To see the pair in 3D, print off this image and view it through a stereoscope. The cropped and processed images were obtained on April 4, 2019, by the PolyCam camera during Flyby 5A of the mission’s Detailed Survey: Baseball Diamond phase.
This anaglyph of site Osprey was made from the stereopairs seen above. Each stereoscopic image was encoded using filters of chromatically opposite colors—one made with red and the other with cyan. When viewed through color-coded anaglyph glasses, each of the two images reaches the eye it’s intended for, and a 3D image is produced. Anaglyphs are helpful for selecting a sample collection site because they allow the team to intuitively understand the three-dimensional structure of things like boulders and craters.
These Boulder Maps for site Osprey detail the number and location of boulders present within the region. Because Osprey has several possible sampling regions, a boulder count map was produced for each of these regions. The boulders are counted by the human eye, using a single image at a time. Many of these boulder counts were made by members of the public who participated in the CosmoQuest Bennu Mappers citizen science campaign. The boulder counter marks each boulder by the longest axis (point to point) in order to calculate maximum boulder size. Rocks that are 10-21 cm are marked in yellow. Anything larger than 21 cm is marked in red. Rocks and debris that are ingested by the spacecraft’s Touch-and-Go Sample Mechanism (TAGSAM) head must be no more than 2.5 cm wide.
Sample Site Location