Researchers at Kazan Federal University (KFU) have conducted a mathematical modeling study to understand the unique diamond-like shape of the asteroid Bennu, which passes Earth at a distance of 75 million kilometers almost every year. This investigation utilized data from the OSIRIS-REx mission, specifically laser altimeter measurements and multispectral images of Bennu.
The study explores the hypothesis that Bennu's diamond shape is linked to the Roche limit, the region around a celestial body where its gravitational forces dominate. KFU scientists aimed to verify this theory by developing a detailed model of the asteroid that accounts for its topography, rotation, and gravitational effects.
Professor Yuri Nefedyev, head of the Astronomy and Space Geodesy Department at KFU, noted that the model reveals a smoother surface in the equatorial region compared to the poles, attributed to the asteroid's position within a rotating Roche zone.
Crucially, the research confirms the theory regarding the influence of solar wind and gravity on the formation of stable orbits for particles ejected by the asteroid. Smaller particles under one centimeter are expelled, while larger ones accumulate around the equator, contributing to Bennu's characteristic shape.
Bennu, a near-Earth asteroid with a diameter of 560 meters, was discovered in 1999 as part of the American LINEAR project. It completes an orbit around the Sun approximately every 1.2 years. The probability of Bennu colliding with Earth on September 24, 2182, is estimated at 0.04%, making it one of the most hazardous celestial bodies for our planet. A potential impact could release energy equivalent to about 1150 megatons of TNT, far surpassing the power of the most potent hydrogen bomb ever tested.