99942 Apophis

Looks like 2036 and a 1-10,000 possibility are the latest
on 99942 Apophis...

www.csmonitor.com...

excerpt

An asteroid, headed our way

By Peter N. Spotts
Staff writer of The Christian Science Monitor
July 26, 2005

Humans live in a vast solar system where 2,000 feet seems a razor-thin
distance. Yet it's just wide enough to trigger concerns that an asteroid
due to buzz Earth on April 13, 2029 may shift its orbit enough to return
and strike the planet seven years later.

The concern: Within the object's range of possible fly-by distances lie a
handful of gravitational "sweet spots," areas some 2,000 feet across that
are also known as keyholes.

The physics may sound complex, but the potential ramifications are plain
enough. If the asteroid passes through the most probable keyhole, its
new orbit would send it slamming into Earth in 2036. It's unclear to some
experts whether ground-based observatories alone will be able to provide
enough accurate information in time to mount a mission to divert the
asteroid, if that becomes necessary.

So NASA researchers have begun considering whether the US needs to tag
the asteroid, known as 99942 Apophis, with a radio beacon before 2013.

Timing is everything, astronomers say. If officials attempt to divert the
asteroid before 2029, they need to nudge the space rock's position by
roughly half a mile - something well within the range of existing
technology. After 2029, they would need to shove the asteroid by a
distance as least as large as Earth's diameter. That feat would tax
humanity's current capabilities.

More info at the article -
www.csmonitor.com...




[edit on 7/26/2005 by FlyersFan]

The truth is, this rock will hit us eventually. Its in a nice steady earth crossing orbit. It even stands a small chance of hitting us in 2029, though thats unlikely.

We need to take this thing out before something bumps it and it makes an unscheduled stop on earth. At 1000 feet diameter, thats a major destroyer, not global, but enough to wipe out most of a state or small country.

This will be a good test to see if humans can pull themselves out of politic and war long enough to stand up to the cosmos.

As in water displacement... Has anyone worked up those scenarios?

Originally posted by Quest
This will be a good test to see if humans can pull themselves
out of politic and war long enough to stand up to the cosmos.

We won't. Unlike the sweet version of events in the movie 'Independence
Day', the world wouldn't come together to fight a common enemy. The
intelectuals would put their energy into saving the planet from the
asteroid, and then the idiots of the world would take advantage of the
distraction to wage war, bomb people, terrorize, take over the planet
... whatever.

I know, that sounds cynical. But that's what I am.
Either that, or I'm realistic.

Good post with good information.

I too hope it helps wake people up to the danger from overhead. If mankid is threateened as a whole, the differences between us all of the sudden don't look so large.

Originally posted by golemina
As in water displacement... Has anyone worked up those scenarios?

In technical terms...big friggin splash.

I have no idea what the velocity, angle of impact, or density of the rock is, so i couldn't tell you. But i'd guess an ocean impact would cause mild tsunami and a lot of cloud formation depending on where it hit an ocean.

Originally posted by Quest
But i'd guess an ocean impact would cause mild tsunami and a lot of cloud formation depending on where it hit an ocean.

An ocean impact is worse. You saw the images of what 800 pounds of 'copper' did on Comet Temple. An ocean impact multiplies the destructive effects of an impact. A massive worldwide tsunami was generated by the ocean impact of Chicxulub in the age of the dinosaurs. In addition, suborbital insertion of superheated melted rock caused worldwide toxic fallout of an average thickness of 1/2", followed by catastrophic atmospheric changes caused by massive quantities of superheated acidic steam injected into the atmosphere.

Chicxulub was 10km in diameter and made a hole 175km in diameter. Apophis is 1km wide. You could expect at least a ten kilometer hole- six and a quarter miles in diameter. As Quest says, not extinction level. But I would bet even money on an Ice Age following impact.

Tagging neos with radio beacons is a great idea. Altering their orbits with pulse units is an even better idea.

Hopefully, we will be back in the serious space business soon with large, capable expendable boosters. The only proper place for potential impactors is the Sun.

Here's a conspiracy thought: could 'someone' have cleaned up most of the Solar System long ago- and have 'parked' the asteroids out in the asteroid belt for mining?

[edit on 26-7-2005 by Chakotay]

Originally posted by Quest
I have no idea what the velocity, angle of impact, or density of the rock is, so i couldn't tell you. But i'd guess an ocean impact would cause mild tsunami and a lot of cloud formation depending on where it hit an ocean.

I can't comment on the cloud formation--although that does seem likely--but I don't think it would be a "mild" tsunami. Aside from any siesmological events caused by the impact (and there probably would be some), the impact would most likely generate a megatsunami.

en.wikipedia.org...

Megatsunamis were first hypothesized by geologists searching for oil in Alaska in 1958. They observed evidence of unusually large waves in the nearby deep inlet called Lituya Bay, Alaska. This is an ice-scoured inlet 220 m deep with an entrance only 10 m wide. The topology of the inlet is particularly suited to producing local megatsunamis. A nearby magnitude 7.5 earthquake on July 8 generated a landslide within the narrow inlet which produced a wave that washed out trees 200 m above normal sea level.

(Emphasis added)

From the UW Geophysics Dept.:

The earthquake-induced rockslide, shown in upper right-hand corner of this image, generated a 525 m splash-up immediately across the bay, and razed trees along the bay and across LaChausse Spit before leaving the bay and dissipating in the open waters of the Gulf of Alaska. Source: Lander, and P. Lockridge

The reason I point it out as a megatsunami is because of the underlying mechanics, and I very well might have the terminology wrong--if I do, I'd appreciate the correction. My usage of the term is from a bad recollection of a discovery special I saw a few months ago.

A regular tsunami, as we all know to some degree after the Sumatra quake, is caused by a displacement of the earth's crust, most commonly an earthquake of course. The height of the tsunami is proportional to the amount of displacement.

A megatsunami is much taller, as the Lituya Bay example, and is caused by a more dramatic displacement of the water, not just an uplift. In Lituya Bay, it wasn't the earthquake directly that caused the wave, but the landslide. With all that extra material sliding into the bay, it actually lifted the water up instead of just moving it away. The result was a wave that was much, much higher than any normal tsunami, and (if I'm not mistaken) left researchers kinda baffled for a while.

In my quasi-educated opinion, the most likely scenario would be a mega-tsunami of this nature--most likely bigger, given the mass and velocity of the asteroid. I believe these have a tendency to have shorter lifespans than your average tsunami, so depending on where it hits the wave may break before it hits the coast.

Of course, just because the wave breaks before shore doesn't mean all the energy is gone, and it will still most likely be traveling much faster than the Sumatra tsunami. Lot of energy, still massively destructive.

Aside from that initial tsunami, the impact is bound to have affects on the sub-oceanic crust, most likely causing submarine landslides and maybe even a couple of earthquakes that in turn cause displacement and/or landslides. I'd say a bare minimum of one extra "normal" tsunami being generated immediately following the inital megawave. Most likely more than that though.

For a decent example of the megatsunami idea, find a lake or pool or bucket of water, whatever. Get a 1 kg rock (roughly 2 pounds), and drop (no force, just drop) it in the water. We'll figure a height of about 1 meter/3 feet (I know not an exact conversion, but close enough) off the water.

Based on equations from here, it takes about 0.78 seconds for the rock to hit, and is therefore travelling at about 7.6 m/s. Note the size of the splash; probably reasonably large, right?

According to basic conversions along with the calculator given here, the asteroid in question is roughly 29.7 billion times as massive as that rock (assuming density of the rock at 2 g/cc), and the velocity will be more in the magnitude of km/s. Not taking the earth's velocity or the velocity of the asteroid into consideration, falling from well beyond the "height" of the moon it would be travelling at roughly 11 km/s. You now have an event that involves an object almost 30 billion times more massive and moving roughly 1,447 times faster than that rock.

As Quest so aptly put it, yes. Big friggin splash.

Apophis an ancient Egyptian god. An evil one if iirc.

Originally posted by FlyersFan
Looks like 2036 and a 1-10,000 possibility are the latest
on 99942 Apophis...

Ohhh I'm so scared, I sure hope I win the lottery by then.

Originally posted by TPL
Apophis an ancient Egyptian god. An evil one if iirc.

Apophis ( Apepi, Apep )
Egyptian snake god and personified darkness, evil and the forces of chaos.
Apophis was the eternal enemy of Ra and cosmic order. Each night he did
battle with Ra on his journey through the underworld on the barque of the
sun, and each night Ra triumphed to be reborn at dawn in the east. Often
the god Set or the serpent Mehen was the one who defended Ra and the
solar barque from Apophis. During an eclipse it was said that Apophis had
gained a temporary victory however, Ra always triumphed in the end. In
one account, it was said that Ra gained a permanent victory over Apophis
when he cut up and burned Apophis' body.

www.angelfire.com...




[edit on 7/26/2005 by FlyersFan]

Originally posted by Chakotay
Here's a conspiracy thought: could 'someone' have cleaned up most of the Solar System long ago- and have 'parked' the asteroids out in the asteroid belt for mining?

Yeah... laws of gravity!
There just ain't much places where that "surplus stuff" could stay in place without getting fast sucked into collision course, being shot out from solar system or drifting around until finding stable orbit.


And considering bigger than kilometers sized objects (like Chicxulub) it doesn't matter so much where it hits, ejecta falling back to atmosphere would heat it so hot that everything compustible not underground or protected would be ignited.


Reason why Lituya Bay tsunami rised so high was not because of some huge energy but because flank of mountain in opposing side was first place
it hit and in that narrow bay there just wasn't really any space to spread.


And diameter of this asteroid seems to be around 320 meters.
neo.jpl.nasa.gov...
neo.jpl.nasa.gov...

source

According to this astrophysicist in 2029 which happens to be April 13th, Apophis will go by earth closer than our communication satellites. That is scary.

Tyson says we have plenty of time to act, react and reassess. "In 2029," Tyson said, "on Friday the 13th in April, Apophis is a certainty to come closer to Earth than our communications satellites. It'll be the largest thing to come that close in recorded history ... and depending on that trajectory, will determine whether it will hit us seven years later."

If it hits, the impact would equal the force of 100 nuclear bombs, said Tyson, the new host of "Nova scienceNOW." The show will devote a segment of its Oct. 3 season premiere to "doomsday asteroids."

His show is on PBS for anyone able to get that.

There is ZERO chance of Apophis hitting Earth in 2029, although (as valkeryie has correctly pointed out above) it will pass closer to us than the communication satellites in geostationary orbit. As for the possibility of an impact in 2036, I think that it is a very good idea to get as much information about this object's orbit as possible. We need very precise orbital information NOW, so that it's "post 2029" orbit can be determined with great accuracy.

What can really be done about this though? Independence Day was an awesome movie, but I doubt we could pull anything like that off. Unless the government has some kind of kick @ss technology we don't know about yet.

It seems like all we can do is prepare for the worst and hope for the best.

edited to change the bad word I accidentally spelled> a to @, I apologize.

[edit on 31-7-2006 by mooonhoxe]

Originally posted by FlyersFan
So NASA researchers have begun considering whether the US needs to tag
the asteroid, known as 99942 Apophis, with a radio beacon before 2013.

OK I know this is a science thread and I don't want to get political or even religious, but what other country would do this? probably no-one even if they could, and many countries moan about the US acting as world policeman but they won't object if the US is trying to save everyones ass will they.

Any ideas how a muslim country would deal with an approaching asteroid? pray 6 times a day instead of 5?

Originally posted by Moley

Originally posted by FlyersFan
So NASA researchers have begun considering whether the US needs to tag
the asteroid, known as 99942 Apophis, with a radio beacon before 2013.

OK I know this is a science thread and I don't want to get political or even religious, but what other country would do this? probably no-one even if they could, and many countries moan about the US acting as world policeman but they won't object if the US is trying to save everyones ass will they.

Very valid point. How about starting a thread on that and getting a real discussion going on this? I'm not saying I agree with you 100%, but maybe 90%

Well, you would have to say that both Europe and Russia also have the rockets to do the job, and I'm pretty sure that they would be keen to help (particularly if their respective countries were the calculated impact site ! Other countries do have launch capability (China, Japan, India etc), but (IMO) they do not have the experience (or reliability) necessary for such a critical job.

Originally posted by Moley

Originally posted by FlyersFan
So NASA researchers have begun considering whether the US needs to tag
the asteroid, known as 99942 Apophis, with a radio beacon before 2013.

OK I know this is a science thread and I don't want to get political or even religious, but what other country would do this? probably no-one even if they could, and many countries moan about the US acting as world policeman but they won't object if the US is trying to save everyones ass will they.

Uhm, who is currently doing the vast majority of the ferrying to the ISS?

Considering that ESA are in the process of going after comets with the Rosetta program, going for a meteorite shouldn't represent much of a problem.

[edit on 1-8-2006 by kilcoo316]

Originally posted by TPL
Apophis an ancient Egyptian god. An evil one if iirc.

Aye, he looked something like this