The asteroid’s equator is tilted by about 175 degrees, so its north pole is pointing “down” relative to Earth’s north pole. Its orbital path is tilted about 5 degrees relative to Earth’s. Bennu makes a close approach to Earth every six years, although its exact distance from Earth during these approaches varies.
It makes one full rotation on its axis every 4.3 hours. By comparison, the smallest planet, Mercury, is more than 3,000 miles across.īennu’s average orbital distance from the Sun is about 105 million miles (168 million kilometers), which is only slightly farther than Earth’s average orbital distance of 93 million miles. Orbit and Rotationīennu makes one orbit around the Sun every 1.2 years. Size and DistanceĪt about one-third of a mile (half a kilometer) wide at its equator, Bennu is minuscule compared to the planets – in fact, it is only slightly wider than the height of the Empire State Building. It may even contain organic molecules similar to those that could have played a role in the start of life on Earth. Because its materials are so old, Bennu represents a type of building block of our solar system’s rocky planets. The best evidence suggests that within 10 million years of our solar system’s formation, Bennu’s present-day chemistry and mineralogy were already established. An ancient relic of our solar system’s early days, Bennu has seen more than 4.5 billion years of history.