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An Asteroid Passed By Earth At About Half the Distance Between Our Planet and Moon (smithsonianmag.com)
On Monday at 7:47 A.M. EST, an asteroid thought to be between 36 and 111 feet wide passed roughly 120,000 miles from Earth -- and astronomers didn't spot it until Saturday. Smithsonian reports: According to astronomer Eric Edelman at the Slooh Observatory, 2017 AG13 is an Aten asteroid, or a space rock with an orbital distance from the sun similar to that of Earth. AG13 also has a particularly elliptical orbit, which means that as it circles the sun it also crosses through the orbits of both Venus and Earth. Lucky for us, 2017 AG13 wasn't a planet killer; according to Wall, the asteroid was in the size range of the space rock that exploded in Earth's atmosphere over Chelyabinsk, Russia, in February, 2013. According to Deborah Byrd at EarthSky, that meteor exploded 12 miles in the atmosphere, releasing 30 times the energy of the Hiroshima nuclear bomb. Not only did it break windows in six cities, it also sent 1,500 people to the hospital. That meteor also came out of the blue, and researchers are still trying to figure out its orbit and track down its origins. While 2017 AG13 would have caused minor damage if it hit Earth, the close call highlights the dangers of asteroids.
>> a space rock with an orbital distance from the sun similar to that of Earth
Presumably, that's why it almost hit us.
In what world does 30 times the energy of Hiroshima qualify as "minor damage"?
in the world where it explodes 30 times higher in the sky than the Hiroshima bomb.
Slashdot, fix the reply notifications... You won't get away with it...
(and without radioactivity)
Slashdot, fix the reply notifications... You won't get away with it...
In what world does 30 times the energy of Hiroshima qualify as "minor damage"?
in the world where it explodes 30 times higher in the sky than the Hiroshima bomb.
In a world where larger asteroids could wipe out most complex life on this planet, a rock "only" big enough to destroy a city is still pretty minor.
I browse on +1 so AC's need not respond, I won't see it.
It was Chelyabinsk-sized. A direct hit on a city could kill millions of people.
You can't just divide the numbers. Gravity pulls stuff in, and the windows are tiny. Think Apollo 13 - only a tiny offset makes the difference between direct catastrophic entry and bouncing off the atmosphere.
And we have NO WAY to change that trajectory anyhow.
Also, statistically the chances are that most humans will die in such an impact - they're rare but when they happen they are INCREDIBLY serious. This was a BIG object, it would have changed life forever. It would have been "an event" not just a random meteorite landing on a desert or ocean.
Also, the bit you're missing? We basically missed this. It's been circling the Sun forever, it's been going to hit us forever, and we didn't spot it. We probably don't have a way to effectively spot it and others like it.
And a few thousands of a degree change in its arc and it would have been something that people recorded for the rest of future history and killed millions. It was only sheer chance that we "escaped".
So, actually, as a mathematician and therefore of a scientific mind, this is a damn sight more important than what some orange fool said about some actress. By orders of magnitude.
Roll on the day when THIS is the news and not all that other junk.
A common measure of the "size" of an orbit is the semimajor axis -- which is half the length of the ellipse. You can have an orbit with a semimajor axis intermediate between those of Earth and Venus that can intersect both of them at various times, if its eccentricity is big enough.
Every gravitational interaction between two bodies alters both their orbits, to a degree that depends on their relative masses and on how close the approach is. This one's orbit will almost certainly change significantly -- hell, even Earth's orbit will change, but by an amount too small to observe.
remember this is the real scale of the Earth to the moon.
http://colchrishadfield.tumblr.com/image/57696912776