NASA's OSIRIS-REX mission will not only take beautiful images of the Bennu asteroid, it will also help scientists learn if the rock will ever threaten the Earth.
There are many reasons to study asteroids. They could be powerful mines for precious resources such as water and heavy elements, and they contain tracks that we can study to learn how the Solar System was similar in its earliest days. But, too, great things that flow into the Earth can have some catastrophic consequences. So scientists are also interested in that.
Bennu is a 1,600-footed asteroid, which orbitates the Sun relatively close to the Earth. OSIRIS-REx, the NASA's mission, which took care of it, launched in September 2016 and reached its goal this past Monday. The spaceship carries five instruments: a camera, a LIDAR system (such as a radar, but with a laser instead of radius waves) and three spectra, which measure different waves of light to determine the composition of the asteroid.
Bennu is a particularly important goal when it comes to our own survival. About every six years, it approaches the Earth ("near" in cosmic terms, but very far from some other measure). Models suggest that during its near agreements between the years 2175 and 2196, it has 1 in 2,700 casualties to fight with us. This is still incredibly small (99.963 percent of failure), but Bennu is a big rock-even slim swelling too much to ignore when civilization is in play.
Why do not astronomers know if we are safe? There are many forces in play, and small differences can change the probabilities. During some of the near approaches of the asteroids, the Earth's importance will give it a little that could move it to a collision. Furthermore, there is the effect of Yarkovsky, according to the launch of Jet Propulsion Lab: the unequal heat of the Sun on such a light body can cause changes in its path. It does not know where Bennu will go after 2135.
OSIRIS-REx and telescopes on Earth will continue to characterize the asteroid, stretching its path and determining how important and effect Yarkovsky will influence its trajectory. The mission will hopefully produce trajectories 60 times more accurately than current rates, according to the press release.
So what happens if Bennu is a threat? Well, you should not be worried personally, because the difficulties are very good for you to be dead. Your children will also probably die (American lifespan decreases, so do not tell me that it is a real thing that we will live longer in the future). But researchers are working on a few solutions. One mission called the Double Asteroid Redirect Test will try to slam a spacecraft in asteroid to cause a change of trajectory. Maybe we could blow asteroids. Or, if we get enough time, we may only paint one side to change how it absorbs solar radiation, utilizing Yarkovsky's effect to our advantage.
Many data are taken before we know what Bennu will do, and many other interesting sciences will lead. But know that Bennu is not the asteroid, of which you are worried about it. The asteroids you should Worry are those who have not yet been detected.[NASA JPL]