Most people are probably familiar with the sometimes eight, sometimes nine gigantic bodies in our solar system but these planets (and one sometimes not-planet) aren’t the only interesting things in our neighborhood. The smaller but still huge chunks of mass known as asteroids hold just as many interesting secrets and one of them, the mysterious Bennu, may finally reveal some of those thanks to the risky but thankfully successful extraction of some samples by NASA’s OSIRIS-REx spacecraft.
Given how many rovers and orbiters we’ve sent to planets and space, you might presume tackling a smaller celestial body like an asteroid would be a piece of cake. On the contrary, it is actually harder to pull off due to many factors, like its spinning movement, requiring NASA to attempt a Touch-and-Go or TAG procedure rather than simply landing the OSIRIS-REx on Bennu’s surface.
In a nutshell, this meant that the spacecraft had to fire its thrusters at least two times to get into position above a target spot called “Nightingale”, one of the extremely few areas clear of boulders that the craft can briefly land on. OSIRIS-REx then fired a burst of nitrogen gas to stir up material from the surface which it would then collect before firing its thrusters again to escape Bennu’s surface. All of these were automated, including a two-story-high boulder nicknamed “Mount Doom”.
The interest scientists have in Bennu is quite understandable and goes beyond the asteroid’s unusual orbit that takes it closer to Earth than any other asteroid, making it easier to reach with a spacecraft. Scientists believe that Bennu is one of the silent witnesses to the birth of our solar system and may hold clues to how life began on Earth.
That said, OSIRIS-REx’s job isn’t over yet. Scientists will still have to determine whether the craft was able to gather enough material for study, a process that is difficult to do remotely from Earth. If it failed to do so, the spacecraft will have to make another TAG attempt in January, repeating the tense and dangerous process all over again.