I'd be far more concerned with Asteroid Apophis than with XP-14 scheduled to fly by this july 3rd.
I'm referring to the 2029 approach, not the return trip of 2036.

It is predicted to come over 10 times closer than XP-14, at a close encounter of only 20,000 miles! AT 1000 feet or so in diameter, that's close enough to hit with police radar! Well, OK,... at least you'll be able to see it with the naked eye, (yours, not mine; I wear coke bottles)

However, more seriously, that's close enough to take out a satellite (or two), and at such a high incoming velocity, possibly alter the asteroid's course ....or at least cause the asteroid, being subject to huge tidal forces of earth already, to break apart and change trajectory toward earth.
Just speculating;...What do you think?

More on the 2029 close encounter: http://www.space.com/scienceastronom...d_apophis.html

Gsquare

I wouldn't be concerned about either. The probablility of impact for Apophis in 2029 is nil. Same for XP-14. Why should anyone be concerned about something we know absolutely for sure, won't happen? If you want to worry about something look up the NEO page at JPL, find an asteriod which has a positive probability for impact for a relatively near time and be concerned about that one Actually Apophis for 2036 may be a good guess. BTW Apophis is 2029 won't be too big a hazard for satelites. Even if we didn't know it was there the chance of random impact with a satelite is tiny, much smaller than meeting a piece of space junk.

Which brings me to my answer on what I'm worried about. I'm not worried about any of the NEOs we've found. It seems neither is a substantial hazard and in any case we should have an advance warning if one of them were to hit. I'm worried about the ones we haven't found yet. Especially the ones which are mostly within Earth's orbit becouse they are next to impossible to find from the ground. Those are the real danger becouse a large one could hit without us knowing anything about it beforehand.

One more comment about this one. Imagine you're on the motorway driving at 180 kilometers hour. Suddenly your car hits a fly. Would you expect your car to go off the motorway and hit a house 500 meters off the motorway directly to your right? Well, I wouldn't. Even if you hit something bigger, a deer for example and the car slid off the road, I'd still be safe in the house becouse the car would continue to go forward thus missing the house. And no we don't have anything comparable to that in high orbit.

Aphphis is estimated to be about 50000000000 kg. Eckelston summed it up nicely. If it hit a satellite, it wouldn't feel it anymore than your car feels a bug hitting the windshield.

However, it won't hit any satellites. It will be above the plane of the geostationary satellites when it passes their distances. Even if it wasn't, there's just too much space for it to have a realistic chance of hitting anything.

Apophis' self-gravity will be at least a magnitude stronger than the tidal force from Earth. So it will remain intact.

How many Apophis 99942 (2004 MN4) threads do we need?

Asteroid Apophis
Apophis
Apophis - What should we do?
Asteroid Close Call Will Be a Gain for Science
Moving asteroid 99942 Apophis
Asteroid heads for Earth
Will it happend?
asteroid strike.. should we be worried????

Bet I can find more.

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We need more 1950DA threads

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"What you think you thought you saw you did not see." Agent J, MiB - Manhatten Bureau

Obviously Apophis needs its own forum.

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Everything I need to know I learned through Googling.

True. If Peak Oil/Nuclear War/Something gives a whole new meaing to the term "post-industrial" this could really mess up 2880.

Man! I so want to somehow capture that rock and turn it into a space station! Anybody know if it's metallic?

It's strange that I've yet to hear of any doomday cults talking about this asteroid. Maybe the date is a bit too far for them to get worked up over - yet. Give it some time, for now they seem to like 2012 better!

It would be a nice second moon if we could grab it.

A Narrow Miss for Earth
Better luck next time, Apophis.

I'm assuming that speed is relative to earth...

A few nitpicks...
would come within 20,000 miles of Earth — close enough to hit some weather satellites.
And miss all the others?

would crash into the planet, or could land in the Pacific Ocean
Land?

If an asteroid hits Earth, Oppenheimer says there are only two things that people can do: Move out of its way or move the asteroid itself.
I would say that when it hits the Earth, it's already too late.

"The best thing to do, actually, is to fly a spaceship up to the asteroid and attach itself,
Not really a nitpick, but I would think for this particular "rock" that the rocket option to shift it's next pass would be extremely difficult due to having to rendezvous so far away. (quite a chace)

Oops, I think I got the two asteroids mixed up (2004-XP-14 & Apophis).

If we could just grab those things we would never need to worry about an asteriod hitting Earth. Distance has never been the problem. The problem is slowing them down enough to be captured by Earth's gravity.

I was watching the PBS "Nova Now" program the other night, where they had a short segment on Apophis. While <those who calculate such things> are quite sure Apophis won't strike the Earth in 2029, they are less certain about 2036. If I remember correctly, it is not possible at this time to exactly predict how the close pass to the Earth in 2029 will disturb Apophis' orbit.

The show went on to identify a rectangle in space. If Apophis passes through that box, it will come back to strike Earth 2036. The show even predicted that if Apophis hit the center of the box that it would strike the Earth in the Pacific Ocean off the coast of California. I'm not sure how much of this is hype (no probabilities of hitting the rectangle were given).

Still, it got me wondering if would seven years be enough time to mount an adequate defense if it looks like Apophis is on a collision course with our home planet on the second pass.

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I may have many faults, but being wrong ain't one of them. -- Jimmy Hoffa

The box is not hype. It is the keyhole. If Apophis passes through it, it will strike the Earth in 2036. The last time new observations adjusted the 2029 pass position, they adjusted it farther from the keyhole.

Think of the keyhole as the sweet spot on a small hill in the middle of a golf putting green. If you aim just perfect, your ball will roll up the hill to its high point, turn (break as they call it in golf) roll down the hill and into the cup. But if you miss this sweet spot by even 1 milimeter, your ball will roll right past the cup. Miss the sweet spot by 1 inch and your ball will miss the cup by several feet.

This is why it is so difficult to predict whether or not it will hit in 2036. Referring to my golf example, we don't know "down to a milimeter" how far the ball will miss the sweet spot on the hill.

If Apophis were found to be on a collision course after the 2029 Earth passage, a strike in the middle of the Pacific Ocean would kill billions as the tidal waves would affect most of the the Pacific Rim. Or more likely, fewer people would die as they had 7 years notice to abandon the coast.

But I would imagine that unlimited resources would be dedicated to deflecting it, and we would be successful.

I didn't agree with the Nova piece's conclusion that nuking it would be a bad idea because we'd get hit with an equal mass of small debris. This is only if we nuked it hours before it hit. Nuke it 3 years before it hits, and the average spacing between particles will exceed 1 Earth diameter.

Apophis seems to be down to 0 on the Torino scale now. In fact there's only one object at 1 - 2004 VD17, in 2012.

(reference: http://neo.jpl.nasa.gov/risk/)

I agree with Tony on nuking an asteroid. Nuke it far enough away, and it will be like flying through the tail of a comet, we might take a hit or two, but nothing that will threaten civilization.

But we don't know what would happen, that's why we need to experiment with nuking an asteroid. But an experiment will never happen, I can just imagine how people around the world would freak out if the U.S. announced such an experiment.

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I'm not a scientist, but I play one on the internet.
http://www.rrac.org

No earth space agency has a division devoted to diverting NEOs . It is very advisable to put some of NASA,ESA's budget and found a new division. Any object like Apophis (which has a dangerous Torino number of 1) should be destroyed or diverted within the next decade before astronomers realize it is too late.

An asteroid the size of Apophis would be expected to damage at least an area the size of Los Angeles or create a moderate tsunami in the ocean.

I am surprised that NASA/ESA didn't make this a priority back in the 1970s .

Hum,
recent discoveries and computer simulations on the effect of smaller `broken-up asteroidlets` show that they can be far more devastating than a single impact.
Multiple airbursts would create a superheated shock blast that would incinerate hundreds or thousands of square kilometres.

Nuking an asteroid may be the worst thing to do.

See `Libyan glass` or `Kebira Crater`

Read more

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`Irony` actually does mean `metal like`...

Apophis remains at Torino 0:

(reference: http://neo.jpl.nasa.gov/risk/)

It may be worth quoting the definition of Torino 1:

"A routine discovery in which a pass near the Earth is predicted that poses no unusual level of danger. Current calculations show the chance of collision is extremely unlikely with no cause for public attention or public concern. New telescopic observations very likely will lead to re-assignment to Level 0."

Hum,
It s also worth quoting the definition of Torino 10 (for future reference)

The probability of an Impact with a asteroid/comet sometime in the future is 100%

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`Irony` actually does mean `metal like`...

Indeed, but sadly for those of us with rather short life expectancies (mine is, optimistically, around 10 years) this certainty will be overtaken by the probability of a more mundane mortality. Pity, in some ways; when one of the various rocks achieved Torino 4 it was, briefly, worth reflecting on the outcome. Sadly or not, that statistic receded.

What we should focus on now is detection. It might not have the appeal of actually blowing something up but with esentially current technology and reasonable funds we could completely rule out (or confirm with absolute certainty) any major impact for the near future and predict minor ones early enough so we could evacuate people if it became necessary. All we'd need is an LSST type survey telescope and a dedicated space telescope at L1 for interior asteriods.

I guess PAN-STARRS and Gaia will go a long way to addressing these issues. Then if we find something we can start to think about how we can best address the problem and if we don't we can run a relatively cheap program that can give ample warning (20-30 years for anything over 200 m would be good enough) if something is about to hit.

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"The cure for boredom is curiosity. There is no cure for curiosity."

Dorothy Parker (?)

Absolutely, detection. Keep looking. Map our environment. And if any perceived threat helps to justify a larger budget, grab it with both hands. Just don't panic. Yet.

Oh, and if there is a threat, I'd guess that careful deflection would usually beat attempts to shatter the rock.

They should add:

Rash attempts to destroy or divert, may lead to re-assignment to Levels 2, 3, or worse.

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Did those computer simulations take into account the debris spreading out over a couple of years? If disrupted soon enough before the expected impact date could Earth sail through the trail and not get hit by a significant number of objects? Obviously hitting an asteroid the day before impact would not be a good idea. But at our present level of technology and the long period time other scenario's would take, such as the Zarkovsky effect, nukes would most likely be our only alternative.

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I'm not a scientist, but I play one on the internet.
http://www.rrac.org

Hum,
indeed,
if it were possible to shift the orbit just by a few centimetres at the correct time then it would not matter if the detonation broke the asteroid up into a deadlier swarm of asteroidlets, (er, Small Solar System Bodies)...
It would be even better if the swarms orbit could be sent completely away from the Earths orbit (captured & mined, or collision with another planet, etc, )

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`Irony` actually does mean `metal like`...

I am surprised Apophis doesn't have a Torino number of 2, or maybe reconsider the Torino scale so it would. Specifically, I would worry that if Apophis passes through the keyhole in 2029, then it'll only be less than a decade to divert it, which is cutting it close. It seems like it would be better to get it out of earth's environment now when we have time, that way there will be no danger. I'd take care of the VD17 asteroid at the same time also.
These are pretty big asteroids.

More troublesome after we get the asteroids down (I doubt one will hit before we do) will be comets. We don't detect those until the nucleus is fuzzed by the coma, and not long before they would hit anyway.