A rock musician working at a computer might seem an unlikely figure in an asteroid-sampling mission, but Brian May brought a specialist skill to Nasa’s search for a place to land on Bennu. The Queen guitarist, who also holds a doctorate in astrophysics, helped scientists turn spacecraft photographs into three-dimensional views of the asteroid’s rough surface. The work became particularly useful when the images revealed a landscape far more crowded with boulders than mission planners had anticipated. May’s contribution, made alongside planetary scientist Claudia Manzoni, later became part of a book documenting Bennu’s unusual terrain and the challenges faced by Nasa’s OSIRIS-REx mission.
How Brian May turned spacecraft photographs into 3D views
May joined the OSIRIS-REx science team in January 2019, several months after the spacecraft arrived at Bennu. His involvement grew from an existing friendship with Dante Lauretta, the mission’s principal investigator, and a shared interest in astronomy. Lauretta was also a Queen fan, though the guitarist was expected to contribute scientific expertise rather than simply lend his name to the project.May had spent years developing an interest in stereoscopic photography, a technique that allows viewers to perceive depth by combining two images taken from slightly different viewpoints. With the right image pairs, the brain interprets the differences between them as a three-dimensional scene. May had used this approach to produce views of Pluto from Nasa’s New Horizons mission and of Comet 67P/Churyumov–Gerasimenko, which was visited by the European Space Agency’s Rosetta spacecraft.OSIRIS-REx did not carry a dedicated stereo camera. That did not prevent May from applying the technique. By identifying suitable photographs captured at different angles and carefully aligning them, he could create three-dimensional representations from images that were originally recorded by a single camera. These views gave the mission team a better sense of the height, depth and relative positions of features scattered across Bennu.
Why Nasa struggled to find a suitable landing site
When OSIRIS-REx reached the asteroid, scientists had anticipated finding relatively open areas that might accommodate the spacecraft’s sampling manoeuvre. The mission had been designed around the possibility of landing in a comparatively smooth patch of ground.The images told a different story. Bennu, which measures approximately 500 metres in diameter, was covered with rocks and boulders, leaving little of the open terrain that engineers had expected. Some formations rose tens of feet above the surface. From conventional two-dimensional photographs, judging the precise shape of the ground and the distance between obstacles was difficult.May worked through the incoming photographs with Manzoni, searching for image pairs that could reveal the terrain more clearly. The task involved examining numerous craters and assessing whether any contained a sufficiently large, accessible patch of ground. May later recalled that he had spent so much time on the work that his musical activities took a back seat.In the book Bennu 3-D: Anatomy of an Asteroid, Lauretta described how the resulting images helped the team appreciate the difficulty of operating on the asteroid. The three-dimensional views made its uneven surface easier to understand and helped scientists and engineers assess possible sampling locations with greater confidence.
Nasa narrowed its search to two potential landing sites
The search eventually narrowed to two candidates: Osprey and Nightingale. Neither offered the broad, uncomplicated landing area originally envisaged. Osprey measured roughly six metres across, while Nightingale was around eight metres wide, making both considerably smaller than the 25-metre target area in the original mission design.Each site had its advantages. Osprey appealed to the engineering team because there were fewer potentially hazardous rocks around its rim. Nightingale attracted the scientists, who believed its surface material might preserve a useful record of Bennu’s history. The colour and composition of the regolith, the loose material covering the asteroid, made the crater an especially interesting place to collect a sample. The decision meant accepting a difficult approach, with a large boulder near the crater’s edge adding to the hazards. The team had to work out how the spacecraft could descend through the surrounding terrain and reach the sampling point without striking nearby rocks.
The sampling attempt revealed another surprise
OSIRIS-REx touched down at Nightingale in October 2020. The spacecraft used its sampling mechanism to contact the surface and collect material before moving away from the asteroid.The operation exposed another mistaken assumption about Bennu. Scientists had expected the surface to behave more like a firm layer of gravel, with some dust and small particles disturbed by contact. Instead, images recorded during the manoeuvre showed a substantial quantity of debris moving around the spacecraft.Bennu’s surface offered far less resistance than expected. The loose collection of rocks, gravel and dust shifted under the probe, raising concerns about how easily the spacecraft might have become trapped or damaged during the operation. The asteroid’s extremely weak gravity also meant that particles and boulders could behave in unfamiliar ways.Bennu is classified as a rubble-pile asteroid, a body made up of fragments held together by gravity rather than a single solid mass of rock. Its structure helps explain why a seemingly straightforward touchdown could produce such an unexpected response. Material that appeared stable from a distance could move when disturbed.
A successful return with more material than planned
Despite the difficult terrain and the unexpected behaviour of the surface, OSIRIS-REx completed its main objective. As reported by Space.com, NASA’s OSIRIS-REx spacecraft departed asteroid Bennu on 10 May 2021, beginning its journey back to Earth with a sample of rocks and dust that exceeded the mission’s minimum collection target of 60 grams.The sample was returned to Earth in September 2023, when the capsule landed in Utah. Scientists gained material that could be examined directly in laboratories, allowing them to investigate Bennu’s composition and the processes that shaped it. The mission was Nasa’s first to collect a sample from an asteroid and bring it back to Earth.Bennu is of particular interest because material preserved within primitive asteroids can provide evidence about conditions in the early solar system. Its loose structure also matters for planetary defence. Scientists need to understand how an asteroid might respond to an attempted deflection, and the spacecraft’s interaction with Bennu offered useful information about the behaviour of its surface.The asteroid has a small but measurable chance of striking Earth in the coming centuries. Estimates cited by the mission team put the probability of an impact at approximately one in 1,800. That does not make a collision likely, but it gives scientists a reason to study the object carefully.
A book documenting Bennu in three dimensions
May and Lauretta presented Bennu 3-D: Anatomy of an asteroid at London’s Natural History Museum in July 2023. Published with the University of Arizona Press and the London Stereoscopic Company, the illustrated volume brings together photographs and stereoscopic views of the asteroid. It also includes 3D glasses, allowing readers to see the images with a sense of depth.The book records more than the appearance of an unusual space rock. It shows how visual techniques developed outside the usual spacecraft imaging process could help scientists interpret data from a mission facing an unexpected problem.
