Okay first on this photograph. That is just huge. This image shows Earth about 280 pixels wide. The asteroid that lead to the mass extinctions at time of the dinosaurs was perhaps 10 km across. Earth is 12,742 km. so on this image, the biggest asteroids we are likely to ever see hit the Earth is about a fifth of a pixel. And the one the news story, if you read the details, is most likely about 580 meters in diameter. So that's about a hundredth of a pixel on this scale of image.
It would be just too small to see.
We did get impacts like this a little over 4 billion years ago. One large impact created the Moon, many think. And after that, the Earth was surely hit by many other monstrous asteroids like this, for some time afterwards n the "late heavy bombardment" that created the largest craters and the lunar mare. But craters as large as say the Hellas Basin and the largest craters on the Moon are all billions of years old.
Our Earth has "swept out" all the largest bodies in our neighbourhood. There is nothing this large in the asteroid belt likely to head our way. And Jupiter does a good job of protecting the inner solar system from objects as big as this from beyond Jupiter. The cratering record speaks for itself. Either they get diverted to hit Jupiter, or the Sun - or they get torn apart by Jupiter or the Sun by tidal forces into smaller objects long before they have a reasonable chance of hitting Earth.
As for this particular object, well we can predict asteroid orbits very accurately now. This one doesn't 'even appear in the Sentry list of asteroids as a potential future impactor. Current Impact Risks
That's the first place to check. If the asteroid doesn't appear there, then that means we know its orbit well enough to be sure it is not going to impact the Earth in the next century.
See also, Is it true that an asteroid will strike earth on 24 September 2015?
Also please see the Asteroid Scares topic.
It would be just too small to see.
We did get impacts like this a little over 4 billion years ago. One large impact created the Moon, many think. And after that, the Earth was surely hit by many other monstrous asteroids like this, for some time afterwards n the "late heavy bombardment" that created the largest craters and the lunar mare. But craters as large as say the Hellas Basin and the largest craters on the Moon are all billions of years old.
Our Earth has "swept out" all the largest bodies in our neighbourhood. There is nothing this large in the asteroid belt likely to head our way. And Jupiter does a good job of protecting the inner solar system from objects as big as this from beyond Jupiter. The cratering record speaks for itself. Either they get diverted to hit Jupiter, or the Sun - or they get torn apart by Jupiter or the Sun by tidal forces into smaller objects long before they have a reasonable chance of hitting Earth.
As for this particular object, well we can predict asteroid orbits very accurately now. This one doesn't 'even appear in the Sentry list of asteroids as a potential future impactor. Current Impact Risks
That's the first place to check. If the asteroid doesn't appear there, then that means we know its orbit well enough to be sure it is not going to impact the Earth in the next century.
See also, Is it true that an asteroid will strike earth on 24 September 2015?
Also please see the Asteroid Scares topic.
About the Author
Robert Walker
Writer of articles on Mars and Space issues - Software Developer of Tune Smithy, Bounce Metronome etc.Studied at Wolfson College, Oxford
Lives in Isle of Mull
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