Asteroid detected on collision course with Earth

General discussion about Celestia that doesn't fit into other forums.
Matt McIrvin
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Science reporting

Post #21by Matt McIrvin » 29.07.2002, 01:30

Thilo wrote:So please stop quoting magazines with journalists or scientists wanting to get money, and drawing the nicest pictures of death while all this what they're telling you might be crap ;)


At this point I think the journalists-- and to an even greater extent, the headline writers-- deserve much more blame than the scientists.

The coverage of this particular asteroid has come in for some very justified criticism from astronomers, who point out that this was really not an unusual asteroid impact threat at all-- asteroid threats of similar magnitude of risk are found, investigated and dismissed dozens of times a year, as part of the normal functioning of near-earth-asteroid tracking efforts that have been in place for the past few years.

They even came up with such things as the automated public Web pages and the Torino Scale to try to communicate something about comparative levels of risk to the public, after a series of badly overhyped threats in the popular media in the nineties. What's frustrating about the latest round of hype is that it seems to have followed the same pattern as if none of this had been done-- initial reports acted as if scientists were telling us the end of the world was likely (at least if you didn't read all the way down to the last paragraph).

No doubt when more observations accumulate and the thing disappears off the threat list, as it almost certainly will (I see that the early potential impact is already gone), the spin will be "the scientists lied" or "the scientists made a silly mistake," when the only people who really misrepresented anything were a bunch of sensationalist folk in the news media.

The deeper problem is that (a) it's very, very hard to convey intelligent information about probability and risk to the public, and (b) there is an active disincentive for newspapers and TV reporters to do so.

Azagoth
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Post #22by Azagoth » 29.07.2002, 04:31

Please,

The impact that wiped out the dinosaurs was a 9.5mile object, the one you're on about (NT7) is 1.24miles. Basically it'll wipe out, roughly 1000miles from centre of impact on land, if it impacts in the sea it'll probably wipe out a few major coastal cities. Enough warning will be given, and there will be minimal loss of life.

Thilo
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Post #23by Thilo » 29.07.2002, 11:25

Matt: yes, you are right there, and i agree with you. Something that had to be said as well..
Though I referred to the consequences, if such an asteroid would hit the earth, what would happen then.

Another thing i think you need to consider:
All people here are talking about "9 miles asteroid" or "two miles asteroid" while there have some different things to be said as well... So for example the direktion of the two bodies at the impact ... if both bodies do a frontal collision, it is very logical that there's a great deal more of destruction happening, than if for example the asteroid would collide from a different direction .. isn't that so? ;)

Raul.
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Post #24by Raul. » 29.07.2002, 12:00

Not to mention what kind of asteroid impacts. A 2Km iron-type asteroid is very massive (and so the kinetic energy is higher).

There are so many factors involved that you can't be sure unless you've a deep knowledge of the object. Anyway, it's only a matter of time, sooner or later one of those mid-size bodies will hit the Earth. But i'd bet we won't see it in our lifetime (Cryonics believers aside :twisted: )

Matt McIrvin
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Uncertainties

Post #25by Matt McIrvin » 29.07.2002, 12:19

Yes, there are definitely uncertainties. The geometry and relative velocity of a possible near-earth-asteroid impact can actually be calculated pretty precisely, but the mass of the asteroid usually isn't known very precisely-- what's known is the brightness, and an estimate of the composition from surface spectrography.

The exception is that the masses of asteroids with moons can be calculated much more precisely-- and, I suppose, for the case of Eros, the NEAR spacecraft functioned as a moon.

One area of concern for ambitious plans to deflect a dangerous asteroid is the question of whether the asteroid is loosely bound enough to break apart if somebody tries to deflect it with nuclear explosions. Blowing up the asteroid would typically not be a good thing; the pieces would still be headed for Earth, with the same kinetic energy, and it would be harder to get them all. This is one of the reasons why there's such interest in studying them up close and even getting at the interiors.

Thilo
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Post #26by Thilo » 30.07.2002, 07:16

If we'd change the asteroid's heading just right, we'd get a second earth moon :D

Sum0
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Post #27by Sum0 » 30.07.2002, 08:18

No... aim it at the frozen water on the moon... result - much needed rain in desert areas!
"I have been asked, 'Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?' I am not able to rightly apprehend the kind of confusion of ideas that could provoke such a question."

Ferret

Post #28by Ferret » 30.07.2002, 10:50

Isn't 200,000X the power of the hiroshima bomb a tad bit powerful?

I think so...

So..It will do a bit more than flood little coastline...

Ferret

Post #29by Ferret » 30.07.2002, 10:54

Raul. wrote:
Ferret wrote:Here's a thought, what if it hits the polar ice caps, it would kinda flood the world...heh heh...

Well, if it hits the north polar cap there'd be huge tsunamis but sea level won't rise at all (i guess that's what you meant). South pole it's a different story...


The north pole is pure ice, the south is land covered with 2km thick of ice..The north pole is quickly melting and in a few 100(?) years time, a lot of land will be below sea level, an impact would speed up this procces a lot...

ogg
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Post #30by ogg » 30.07.2002, 13:44

this is rapidly getting off-topic, but as far as I understand it, only the melting of ice sheets resting on land will serve to raise the ocean levels, because the ice sheets floating in the northern oceans already displace ocean water like someone floating in a bath. To raise the sea levels you'd want to hit the greenland ice sheet or the west antarctic ice sheet down south.
But anyway... how much would melt, really? I recal someone quoting the figure of 100 Hiroshima bombs for this latest media 'hoax', and that's really not that much of a heat input given the vastness and super-sub-zero temperatures of all that ice. The soviets were letting off blasts of that magnitude in the 60s and 70s and Russia is still just as cold as it was.
___________

ogg
___________

Malcolm

Post #31by Malcolm » 30.07.2002, 14:01

I agree with ogg,, and further :
the most recent 'hoax' in the media is that the N.pole has melted so much that there was now "Open water at the north pole, Shock, Horror"
Until the scientists pointed out that it was summer in the northern hemi. and that it was quite normal for the ice to thin & to break up & to be able to find patches of clear water amongst the n.polar ice cap.

Raul.
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Post #32by Raul. » 30.07.2002, 22:17

Ferret wrote:The north pole is pure ice, the south is land covered with 2km thick of ice..The north pole is quickly melting and in a few 100(?) years time, a lot of land will be below sea level, an impact would speed up this procces a lot...


Assuming you know the north polar cap is floating (except ice on Greenland) the rest is Physics 101 :lol: .

Suppose you have a glass of water and you add a couple of ice cubes, mark water level and let the ice melt. Oh, surprise, water is still on the mark not above :twisted:. :wink:

timmy

ssc code for windows NT7

Post #33by timmy » 31.07.2002, 17:47

"2002 NT7" "Sol"
{
Class "asteroid"
Mesh "asteroid.cms"
Texture "asteroid.jpg"
Radius 1000

EllipticalOrbit
{
Period 2.29006 # 837.006 days
SemiMajorAxis 1.737371050648156
Eccentricity 0.5298591345915969
Inclination 42.35242940965551
AscendingNode 132.1668482301468
ArgOfPericenter 300.6108078384685
MeanAnomaly -57.32033640196821
Epoch 2452473.5
}

RotationPeriod 18.0
Albedo 0.1
}

radius is in meters! not kilometers!

Guest

Post #34by Guest » 31.07.2002, 18:04

Thanks...I thought it was a bit small :)

mmouvet
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Global threats...

Post #35by mmouvet » 01.08.2002, 03:20

Anonymous wrote:A little off-topic, this, but :
Stargazer said :
Asteroids are the only real threat to the survival of the human race for the time being, except from ourselfs, that is...

Anyone who watches the BBC's Horizon programmes (or reads New Scientist) will tell you that as well as huge killer asterioids/comets, small killer asteroids/comets, and ourselves, other threats to our existence include (to name but a few) :
Supervolcanoes - most notably the 70km wide caldera of Yellowstone, which is due for an eruption.
Pandemics.
Earthquakes.
Ultra-huge tsumanis cause by landslides (watch out if you're on the east coast of America - the island of La Palma looks rather shaky).

Scaremongering is all very well, but we can't very well do a lot about a supervolcanoe or earthquakes or tsunamis. So why worry ?
(yes, I suppose we need a better asteroid monitoring system though)

(Mad Boris)


I think you forgot about the probable cause of the dark ages from 535AD and the plague - krakatoa... 8O


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