That asteroid is now known as (99942) Apophis. It will approach the Earth very closely indeed in 2029 (approximately 32,000 kms; that's exceptionally close for an object as large as 300 metres in diameter).

The reason that astronomers can't yet conclusively rule out an impact in 2036 is because the orbit of the asteroid will be significantly changed by the Earth's gravity during the 2029 close approach. A very slight discrepancy in the calculated position and velocity of the asteroid at this time would result in a massive difference seven years later.

But what if it collides with the Moon?

If it collides with the Moon, then we don't need to worry !

Originally posted by Raabjorn
But what if it collides with the Moon?

You won't have to worry about that, on the 2029 pass at least, because the Moon will be nearly opposite it from Earth.

Oh, and if it does collide with the Moon - Yes, we would need to worry. Why? Because that could send debris to Earth, which could damage satellites and even impact down here.

[edit on 7/20/2006 by cmdrkeenkid]

If Apophis hit the Moon, a large percentage of the impactor (and the Moon's surface directly beneath it) would be vapourised. Some chunks certainly would be ejected clear of the Moon's gravity, but they would be a tiny fraction of the size and mass of the initial object.

True, but a lot of that vaporized material would then condense rather quickly. Following that, the larger chunks could hit the Earth. If not, we'd probably play host to a rather spectacular display of meteors.

In addition to the vast percentage of the asteroid being vapourised, it is also true that the vast majority of the vapourised material wouldn't escape from the Moon's gravitational field. That would only leave a small fraction of the impactor's mass free to potentially impact Earth.

[edit on 20-7-2006 by Mogget]

[edit on 20-7-2006 by Mogget]

It would entirely depend on the velocity at which the ejecta was blown out. One of three things could happen: A.) It could fall back to the Lunar Surface; 2.) It could stay in orbit around the Moon (and if thick enough possible even form a ring system); or III.) Reach escape velocity where it could pose a hazard to satellites or the Earth itself.

I'm not trying to argue about this with you, just pointing out from that one post you made saying to worry that you shouldn't just brush that idea aside, that's all.

If it did hit the moon, wouldnt it cause a gravity bump wave or something, in turn causeing huge tsunamis ?

I'm not trying to argue about this with you, just pointing out from that one post you made saying to worry that you shouldn't just brush that idea aside, that's all.

Don't worry. I'm not looking for an argument

Those areas of increased gravity are due to large concentrations of iron and/or other metals near the surface of the Moon. The higher density of these materials results in a localised concentration of mass, and this can measurably deflect the trajectory of a satellite in lunar orbit. One impact wouldn't make a detectable difference, so these must be the result of hundreds of impacts in the same general area (presumably by asteroids rich in metallic elements).

I wouldnt trouble your mind if i were you. Just sum it all up. Earth has millions of scientific minds, improving technology ... and chuck Norris' right upper cut. And the giant lump of rock has hmmm momentum? maybe?

So id say thats earth = 1 ... lump of rock 0

Wait, are yo sure about this asteroid. How big is it. Do you have any evidence to substantiate your claim?

Wait! Asteroids rotate around its orbit just like Earth?

Wait! Asteroids rotate around its orbit just like Earth?

Gee, nobody ever mentions Touatis - Asteroid 4179 Toutatis (1989 AC).

She gets close in 2008, but even closer in 2012. If she doesn't crash into us then, then it will be a long time before she catches up to the earth again like on the order of another hundred years or so.

I guess they don't like talking about this rock because its, ahem, 2.7km in diameter.

Qoite: gee, nobody ever mentions Touatis - Asteroid 4179 Toutatis (1989 AC).

She gets close in 2008, but even closer in 2012. If she doesn't crash into us then, then it will be a long time before she catches up to the earth again like on the order of another hundred years or so.: qoite

SO first it takes 19 years to complete a orbit in what ever path for us to line up then it takes 4.... yaaa i don't think thats right.

I very much doubt we will even see that year as i reckon we will have nuked ourselves out of exsistance by then, & thats if we make it past 2012 - or even to 2012 the way things are going.

Originally posted by mashup
I wouldn't worry. The world's gonna end in 2012 anyway.

In the unlikely chance that the world doesn't end in 2012, I'm sure that they'll have some sort of new technology by then.

Either way, I wouldn't worry.

If you think this is going to happen its not, there is no proof exacly, it was the Mayan Calender