Huge Asteroid to Fly Past Earth July 3

[Neeyik]

What are you talking about?
Seriously, there are PMs.
If you need to talk to me, use PMs.
I realise that you don't like me but there is no reason to put it out publically.

Like/dislike has nothing to do with this. It's simply a case of pointing out that doing the silly "we're all going to die of black holes/asteriods/LGMs" in virtually every single astronomy thread has got really annoying and, on face value, quite immature. However, most regulars here understand your sense of humour and know quite full well that you're actually not immature, stupid or childish; I was hoping to point out that this was the case by referring to your reply but my last comment, including the "rolling eyes of exasperation", doesn't read very unfortunately and for that you have my apologies.

However, since you're getting quite narky about this, I have no intention of talking any further on this matter. There is simply no need for the silly replies in virtually every astronomy thread about moving objects in the solar system.

 

[_xxx_]

A related problem to look at is Buffon's needle.

What, the italian goalkeeper?

 

[Deepak]

Yah, I'm a bit late t the party but regarding to this quote, yes with a big but. The gravitational well of earth is miniscule compared to the gas giants and the sun. So any objects will have a tendency to head towards larger bodies and ignore earth all together.

This makes any earth impact a rare event indeed. It is thanks to the outer rim planets that life can thrive on earth.

Yeah, I remember reading somewhere that Jupiter has been a great boon for earth as its gravitational pull ensures that most asteroids collide with itself.

 

[Mintmaster]

Whoops, I should have payed a little more attention to this thread.

KILER, yes, read my post again. If 3200 passed by earth and all were guaranteed to be closer than 432,608 km, then there's a 50% chance of all of them missing us. The earth has a radius of 6400 km. Use a little common sense before freaking out.

Now if you only get 1 every 1500 years then there is a 50% chance that the earth will get hit by one every 4.8 million years.

I actually missed that last part of the article talking with the 1500 years figure. However, remember that they say an asteroid passes by within 20,000 km at that frequency, which is substantially closer. Each of these asteroids has a 7.6% chance of hitting us. However, that's only 300m in diameter, and not capable of apocalyptic damage.

We don't know what the frequency is for a situation like XP14. Could be higher or lower.

 

[KimB]

Yah, I'm a bit late t the party but regarding to this quote, yes with a big but. The gravitational well of earth is miniscule compared to the gas giants and the sun. So any objects will have a tendency to head towards larger bodies and ignore earth all together.

This isn't true at all. The gas giants will draw asteroids and comets towards earth just as often as they draw them away. They can help to reduce the total number of asteroids/comets in the solar system merely because they have a greater effective cross-sectional area. But more comets/asteroids colliding with them has nothing to do with the objects heading towards larger bodies. It has to do with the larger bodies being, well, larger, and thus easier to hit.

As a quick example, if Jupiter was much smaller, it might not have disrupted the formation of the planet that would have lied between Mars and Jupiter. Without the asteroid belt, we would be significantly safer from the impact of asteroids (since this is one place where objects that can impact Earth come from).

 

[KimB]

By the way, neither of the objects discussed here would cause extinction-level events if they collided with the Earth. An extinction-level event would be a collision of an asteroid with a roughly 10km diameter (or more). These are believed to happen roughly once every hundred million years, and I don't believe there are any known candidates for collision in the relatively near future.

The asteroid that will make for a near miss in 2029 has a small chance of hitting us the next time around, as its orbit will be disrupted when it passes, by an amount we can't accurately predict. But at 300m, it'd be pretty destructive, but not capable of anything like a mass extinction.

Edit: Oh, and the smaller impacts caused mass extinctions due to the rapid climate change, not the actual impact damage. As an example, the extinction event at the end of the Cretacious period lasted thousands of years. The reason why the dinosaurs died out en masse wasn't because of the impact, but because of the ash kicked up into the atmosphere that changed the climate. Those that couldn't adapt died (which was most of the larger animals). Humans would easily be capable of surviving an extinction event of this magnitude. We wouldn't think everything was all rosy and fine, of course, as it would be a major disaster, but it wouldn't kill us off.

Source:
http://en.wikipedia.org/wiki/Impact_event

 

[LunchBox]

don't worry if an asteroid comes our way...
we can always send Bruce Willis and Ben Affleck to mine it and cut it in half...

on another note...
I forgot which Aerosmith song was in that movie...
I don't even remember the title of that particular movie...
I jusr remember seeing it late at night on cable....