NASA’s OSIRIS-REx probe continues on a mission to unravel mysteries and help tell the story of Bennu, affectionately called the “end-of-the-world asteroid”. About to collect rock samples at the site, the equipment has already helped through observation to answer some questions —and bring many other questions—about the space rock.
New studies published in journals such as Science, based on data and images from 2019 collected from infrared scans, show that it is more complex than previously thought.
For starters, the presence of carbonated minerals was detected in one of Bennu’s craters, accompanied by “canals” on the surface that suggest that running water had been present on the asteroid. However, this probably happened at a time when it was still part of one or more larger celestial bodies, whether remnants of a planet or another asteroid. Scientists have also found on the surface porous and fragile dark rocks, which are rich sources of carbon.
Another surprise is a difference in the mineral composition of the hemispheres: the northern part of the asteroid is more rocky and irregular, while the south is rounded, still without an explanation for it. Their coloring is also interesting: a shade of blue rather than red as expected.
There is no explanation for this so far, but the process may be a result of interaction with solar winds and collisions with small meteorites. It is worth remembering that Bennu is a frequent theme of conspiracy theorists, who have identified alleged signs of construction and even traces of life in previously released photos.
In addition, Bennu’s gravity was detailed by one of the studies. It is quite weak and also irregular, being much denser in the center of the rock —something probably explained by a very intense rotation at the beginning of its formation.
The next step in the OSIRIS-REx mission involves collecting space dust that is released from Bennu. The results of the samples, however, will come out only in 2023, with the return of the probe to Earth. The goal of scientists is not only to find out more about the asteroid, but also to get more clues about the moment of formation of the Solar system.