You are probably thinking about asteroid Bennu because NASA are going to launch a mission to it on 8th September, the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) mission. No, Asteroid Bennu Won't Destroy Earth

So, yes there is a 1 in 2700 chance that it will hit us some time in the 22nd century, at some point between 2175 to 2196. That means that there are 2699 chances in 2700 that it will not hit, so it is very likely that it won’t hit.

At 490 meters diameter, is too small to have global effects, though it is just large enough to cause a tsunami if it hit the sea according to this paper.

And so long as we have space technology at that point, if we do find it is headed our way when the time comes, a gentle nudge a decade or two before the flyby will be plenty to make sure it misses, to change its velocity by of order of cms per day. Or even less if it does a flyby of Earth first before the impact, as it would then only need of order of microns a day adjustment. With such a long timescale we could prevent it hitting Earth by simple measures such as painting its surface white. But 160 years is also far enough into the future that we could just mine it away to nothing by then if we develop space mining by then. Many possibilities.

But it’s not remotely an extinction level event. And indeed, we are no longer hit by asteroids much larger than 10 km in diameter. The big craters on the Moon date from the early solar system, all of them are from over three billion years ago, and you can’t find a crater anywhere in the inner solar system inside of the asteroid belt for the last three billion years that was created by an impactor significantly larger than 10 km in diameter. Since 100 km diameter and larger objects must come into the inner solar system from time to time, the conclusion, also supported by modeling, is that Jupiter protects us from the larger asteroids by diverting them away, including diverting them to hit the Sun or fly close enough for it to evaporate them - or diverting right out of the solar system or breaking them up into smaller pieces. It doesn’t do such a good job of protecting us from 10 km size asteroids and smaller though many of those also hit Jupiter so it does help with some, others though it might actively send our way.

There are larger asteroids in the asteroid belt that would in theory cause serious harm on Earth if they were diverted our way - but they are all in stable orbits for millions of years into the future, and again there are no craters on Mars, or its moons, our Moon, Mercury, and what we have of the history of Venus or Earth from any objects that large either, so they have been in sufficiently stable orbits to not threaten us for three billion years. Smaller asteroids from the asteroid belt do get diverted inwards by tugs of Jupiter’s gravity.

So in short we only need to be concerned about roughly 10 km scale asteroids at the largest. Those are certainly nowhere near large enough to end all life on Earth. They are also very improbable. 99.99999% certain that we are not hit by one of those in any given century.

The dinosaur extinction event caused extinction of perhaps 70% of all species. But small mammals, turtles, crocodiles, birds, dawn sequoia, many species survived. Humans are amongst the most reilient of all creatures on Earth with just a tiny amount of technology, even stone age technology. Can survive anywhere from the Arctic to the Kalahari desert. And we are omnivores, can eat anything from fruit, crops, animals, sea creatures, shellfish, just about anything. I can’t see even a major impact like that making us extinct, there would be some survivors at least who would then rebuild civilization. And there would be places on Earth opposite the impact especially that would be hardly affected, retain their technology, in submarines also, and many of us would survive the nuclear winter.

So - worst case scenario of the largest asteroid impacts is widespread chaos and suffering. But not extinction.

But - we can detect asteroids, know how to do this, just need the funding for it. We can deflect them easily if we have a long enough lead time. It’s the one natural disaster we can predict to the minute at least a decade or two in advance, and then prevent easily too. The main gap here is knowledge - we hope to find 99% of all the 1 km asteroids by the 2020s. Bennu is a bit below that limit but with some extra funding for a dedicated space telescope we can find just about all the smaller ones too by then.

And the probability of “death by asteroid” is minute. It’s far less than the chance of dying by lightning or tornadoes. And far far less than the chance of death from a traffic accident (as pedestrian, passenger or driver).

For more on this see my Giant Asteroid Headed Your Way? - How We Can Detect And Deflect Them (free to read online) also available as a kindle booklet

Giant Asteroid Is Headed Your Way? : How We Can Detect and Deflect Them (Amazon)

Also my Could Anything Make Humans Extinct In The Near Future?