Sandpiper

(-47°, 322°)

Site Sandpiper is in asteroid Bennu’s southern hemisphere, on the southeast floor of a large crater with a radius of 103 ft (31.5 m). The site itself is a relatively flat area with a 16 ft (5 m) radius. Sandpiper is surrounded by steep slopes and large boulders that are scattered throughout the area. There are two smaller, relatively young craters near Sandpiper that may have ejected fresher material into Sandpiper’s sampling region. Sandpiper has the second highest albedo variation among the possible sample collection sites. Hydrated minerals are also present, which suggests that Sandpiper may contain potentially unmodified carbon-rich material.

Reconnaissance A Imagery

This is the highest-resolution image of candidate sample site Sandpiper that’s been captured as of October 5. Site Sandpiper is located in asteroid Bennu’s southern hemisphere, and the region of interest is visible in the center of the image (situated above the large boulder). The image was taken by the PolyCam camera on NASA’s OSIRIS-REx spacecraft on October 5, from a distance of 0.6 miles (1 km). The field of view is 48 ft (14.6 m). For scale, the large, light colored boulder in the bottom center of the image is 16 ft (5 m) wide, which is about the size of a box truck. For scale, the large, light colored boulder in the bottom center of the image is 16 ft (5 m) wide, which is about the size of a box truck. The image was obtained during the mission’s Reconnaissance A phase. When the image was taken, the spacecraft was over the southern hemisphere, pointing PolyCam slightly south and to the east.

Digital Terrain Model

The crater’s steep slopes stand out in this 3D printed model, along with the ruggedness of Bennu’s southern hemisphere where Sandpiper is located.

Credit: NASA/Goddard/University of Arizona/CSA/York/MDA

Stereo Pair

This set of stereoscopic images provides a 3D view of site Sandpiper, located in Bennu’s southern 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, download the image and view it through a stereoscope. The cropped and processed images were obtained on March 21, 2019, by the PolyCam camera during Flyby 3 of the mission’s Detailed Survey: Baseball Diamond phase.

Anaglyph

This anaglyph of site Sandpiper was made from the above stereo pair. 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 objects like boulders and craters.

Boulder Count Map

This Boulder Map for site Sandpiper details the number and location of boulders present within the region. 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.

Scale Comparison

The OSIRIS-REx spacecraft is about the size of a 15-passenger van, so for a familiar perspective, this is site Sandpiper superimposed over a standard parking lot. Sandpiper, which lies within the white circle, covers roughly 6 parking spaces. The width of each parking space is 9 ft (2.7 m).