NASA’s science probe OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer) arrived at the asteroid Bennu last week. After a few weeks of reconnaissance of the small object, the spacecraft will move in close enough to go into orbit around it. NASA’s OSIRIS-REx Spacecraft Arrives at Asteroid Bennu – NASA

Now, at about 11.8 miles (19 kilometers) from Bennu’s Sun-facing surface, OSIRIS-REx will begin a preliminary survey of the asteroid. The spacecraft will commence flyovers of Bennu’s north pole, equatorial region, and south pole, getting as close as nearly 4 miles (7 kilometers) above Bennu during each flyover.

The primary science goals of this survey are to refine estimates of Bennu’s mass and spin rate, and to generate a more precise model of its shape. The data will help determine potential sites for later sample collection.

OSIRIS-REx’s mission will help scientists investigate how planets formed and how life began, as well as improve our understanding of asteroids that could impact Earth. Asteroids are remnants of the building blocks that formed the planets and enabled life. Those like Bennu contain natural resources, such as water, organics and metals. Future space exploration and economic development may rely on asteroids for these materials.


This image of Bennu was taken by the OSIRIS-REx spacecraft from a distance of around 50 miles (80 km).  Credits: NASA/Goddard/University of Arizona

After a couple of years of study, the spacecraft will obtain a sample of the asteroid and return it to earth: 

When OSIRIS-REx begins to orbit Bennu at the end of this month, it will come close to approximately three quarters of a mile (1.25 kilometers) to its surface. In February 2019, the spacecraft begins efforts to globally map Bennu to determine the best site for sample collection. After the collection site is selected, the spacecraft will briefly touch the surface of Bennu to retrieve a sample. OSIRIS-REx is scheduled to return the sample to Earth in September 2023.

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