This colorful new glimpse of asteroid Bennu is the first 3D lidar map created since the OSIRIS-REx spacecraft’s arrival at the asteroid in December 2018.
The three-dimensional shape model is based on data gathered by the Canadian Space Agency’s OSIRIS-REx Laser Altimeter (OLA) instrument.
To create the image, over 11 million laser pulses were fired and captured by OLA between February 12 and 27 as OSIRIS-REx flew less than 1.2 miles (2 km) above the surface – the closest orbit ever achieved by spacecraft.
OLA obtained these measurements by firing laser pulses at Bennu and measuring the amount of time it takes for the light to bounce off the asteroid’s surface and return to the instrument. That time measurement is then translated into altitude data. Using this data, the OLA team created the 3-D model of Bennu’s surface. The colors represent the distance from the center of Bennu: dark blue areas lie approximately 197 feet (60 meters) lower than peaks indicated in red. Some parts of the asteroid have not yet been measured, which creates gaps in the image.
Throughout 2019, OLA will take nearly a billion more measurements to complete the first-ever high-resolution 3D lidar map of a near-Earth asteroid. The data collected will be essential in identifying a suitable sample site.