Thanks, I was interested in this. I heard about it on the regular news but it wasn't on spaceweather.com yet. There was a similar event a few months ago with a bigger object that passed a couple of LDs from Earth and wasn't seen until it had passed as well. Doesn't give one a lot of confidence we will see these things before they hit. [img]/phpBB/images/smiles/icon_eek.gif[/img]

<a name="20020621.2:00"> page 20020621.2:00 aka 2002 MN
On 2002-06-21 05:03, beskeptical wrote: To: 3 KAN 18 ZOTZ
2002 MN has an orbit of 894.9 DAYS ?
120 metres 10 megatonnes
2:01 A.M. preliminary Numb's
2nd edit later

Let's see now. According to the article:
IIRC The Hiroshima bomb was 15 KT. 15 x 600 = 9 MT. But the article also says:
If 2002 MN is twice the length of the Tungusta object, wouldn't that give it a mass of 8 times that of the Tungusta object and therefore put the projected blast int the 70-80 MT range. This doesn't even take into account thae wide range of materials and densities of asteroids (carbonaceous chondrites, stony, stony iron, nickel iron, etc.). The meteor that dug Barringer crater has been estimated to have been a 20 meter stony iron meteor.

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Any day you wake up on "the right side of the dirt" is a good day.

T. Anderson

It depends on the velocity of the object as well. An meteor coming from an apogee beyond pluto will be moving faster in this part of the system than the same sized meteor coming from an apogee near mars.
--Tommy
http://www.tommyraz.com

tesla claims to have cuased the tunguska event in the book "man out of time", it was his "death ray" experiment, it freaked him out and he destroyed it.

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ncredible
Justn

A miss is a miss, is a miss.....


Think of all the time we could spend talking about things that 'didn't' happen..

Uhhh.. did I really say that.. I guess we do that all the time.. (talk about things that 'didn't' happen).

<font size=-1>[ This Message was edited by: Diogenes on 2002-06-21 15:03 ]</font>

Doesn't it concern you at all that this is the second near Earth object recently that was not detected until it passed? I'm not worried about the near miss. But I am a bit concerned about our blind spot.

Not that I'm losing sleep, hmmm... it is late...

I think I'll just take things as they come, big rocks and all.

Should we lose sleep over it? What could we do to stop such a large object from impacting our planet? Are there any contingency plans in operation here?

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With the lowly cattle stringing, Clancy rides behind them singing For the drover's life has pleasures That us townsfolk never know.
- AB Paterson; Clancy of the Overflow

What are we doing about it?
Not a lot. Or, not nearly enough. As those in the know like to say, the number of people mapping NEO's and likely impactors is about equal to the number of people working in a single MacDonalds.
<sigh. During the 80's I had to worry about the Cold War turning hot and nuclear war. Now all I have to furrow my brow is the risk of a big rock falling on me from a great height!

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Garlic Bread?!?!

I took particular notice of this part of the article:

"...the search for dangerous asteroids is overwhelmingly conducted by telescopes in the northern hemisphere. A rock approaching from the southern hemisphere could go undetected."

Here's why we have this ridiculous state of affairs:

http://www.space.com/scienceastronom...ia_020319.html

Unbelievable. A piffling million dollars a year is all that it takes to avert a possible disaster. But since funding was cut by the then newly-elected Liberal party in 1996, any massive asteroid approaching from the south will likely do so unseen and we'll be absolute toast! Nice one, Peter.

I remember reading somewhere else that the Hon. Peter McGauran also said, "I lie awake at night worrying about many things. Asteroids is not one of them". Numbrain (but then again, he is a Liberal MP, so what more could we expect).

Curse the day that snivelling little Johnie and the Libs came to power in '96 and curse the ignorant Aussie masses who've kept them there since. - I can only get away with saying this because I'm Australian myself [img]/phpBB/images/smiles/icon_wink.gif[/img]

Cheers,

JB

__________________
Nowhere in all space or on a thousand worlds will there be men to share our loneliness. ...in the principles of evolution we have had our answer: of men elsewhere... there will be none, forever. - Loren Eisely, The Immense Journey, 1956.

I kinda reckon Australia's got more important things to do with their money, though I'm not going to get into a political debate. We have a smaller population, and therefore less taxpayer funds, to use on such projects, in comparison with many northern hemisphere countries.

Besides that, Australia is the most economically secure nation in the southern hemisphere, and so it makes it difficult to share the burden with the poorer countries.

Anyhow, what would we do if we spent a million dollars to look at the sky and see a great big rock coming at us? "Yep, there it is. Gee, it's big."

Then what?

I think you'd have to convince a politician of serious threat to national interests before they'd approve a budget like that. Besides, their more concerned with the arts and medical sciences these days. They can win votes with those. [img]/phpBB/images/smiles/icon_smile.gif[/img]

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With the lowly cattle stringing, Clancy rides behind them singing For the drover's life has pleasures That us townsfolk never know.
- AB Paterson; Clancy of the Overflow

What can we do?
1) Panic! (not very productive)
2) Carry out an emergency planning and evacuation programme for the impact site.
3) Begin a crash-programme building satellites armed with gigaton nuclear warheads, Asteroids for the Destruction of.
4) Ring up Number 10/White House/Kremlin and say "I told you so"!

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Garlic Bread?!?!

My point is, if it didn't miss, we might not be talking about it..


It is a variation on the theme of " If things were different, they would be different."


Like when creationists like to point out things like: " If the Earth were a little farther from or closer to the Sun, life as we know it, would not exist." ... and they are exactly right, it wouldn't!!

But that does not mean/prove that 'life' would not exist.

<font size=-1>[ This Message was edited by: Diogenes on 2002-06-24 18:00 ]</font>

Lucky, I see your point there, and your "Gee, it's big" comment is well taken: I think the United States military recently admitted that they currently have nothing, absolutely nothing, with which they could prevent the impact of a large asteroid.

However, that doesn't mean that something couldn't be developed if an asteroid with an impact trajectory was located some years before it arrived. And that's why I think we need countries with the really big scopes doing the SNEA/Spaceguard survey. Remember, there is currently no telescope time being allotted to this task anywhere in the southern hemisphere.

A million dollars really is a miniscule percentage of a country's science budget, even for an underpopulated middle power like Australia. As far as I know, the United States currently commits three times that amount to the search for near-Earth asteroids. Good for them, they've got the northern skies at least partially covered, even if the project's scope (no pun intended) is seen as woefully inadequate.

But what about the south? Most southern hemisphere nations are too concerned with their own internal economic and military security issues to even think about looking skyward. I think the onus falls on the prosperous and secure nation of Australia to take up the task. Clearly nobody else will.

I agree that even such a small budget expenditure might cause some grumbling from the electorate. But that's where a small awareness campaign could come in handy (that goes for the rest of the world, too. Ask the average Joe on the street anywhere how much he knows about asteroids).

Dr. Duncan Steel (Steele?) said: "The dinosaurs didn't have a space programme. That's why they all died." Perhaps that's a little extreme, but the man has a point. If you consider that the chances of a 'doomsday' asteroid striking the Earth are about the same as the chances of you or I dying in a plane crash (sorry, can't recall the source for that estimate), then you have to admit that large asteroids, however rare, do pose a significant threat. Just as we are personally concerned about air safety, so should the planet as a whole be concerned about impact-trajectory asteroids.

Cheers,

JB

(edit sp.)
_________________
"Nowhere in all space or on a thousand worlds will there be men to share our loneliness..."

- Loren Eisely, "The Immense Journey" 1956

<font size=-1>[ This Message was edited by: Jovianboy on 2002-06-24 23:53 ]</font>

So, what's wrong with the way we determine how to invest prevention dollars. Easy, no risk benefit analysis, and, short term gain almost always supercedes long term gain even if it is clearly better to go for the long term.

How much should we invest in detecting NEOs?

How likely are we to be hit by a large object? 100%. Odds per year, I'll leave that to the astronomers.

Can we successfully intervene? Probably, given enough time and funds.

Cost to intervene, enormous; cost of not intervening, enormous.

How about alternatives. If we invested enough to thoroughly monitor the skies, and if we detected an object on course to hit us, then the benefit of investing to intervene would be worth the risk of not spending those dollars elsewhere. I mean, gee, what else are you going to spend the money on if we are all dead?

What if we do nothing and use the money on other priorities? Since there is 100% chance we will be hit by a large object, I vote to keep a better look out.

Fortunately, I think the Sloan Digital Sky Survey is going to give us a very detailed picture of the skies. The project is underway. It is an incredible tool that has a 7 degree field of view in great detail due to millions of dollars worth of some fancy digital computer lenses. It will literally be able to scan the entire sky nightly, from my understanding of it. And, since it will be on an orbiting satelite, it shouldn't miss a hemisphere. (If any of you much better informed astronomers are aware of the actual details, please correct any misunderstandings of the project that I may have.)

I just love new tools. [img]/phpBB/images/smiles/icon_biggrin.gif[/img] I can't wait to see the data.

<font size=-1>[ This Message was edited by: beskeptical on 2002-06-25 00:12 ]</font>

I understand what you're all saying. You're right that the buck stops with Australia for keeping watch on the southern skies.

I guess all you have to do now is convince the politicians. I was watching an Australian science program called 'Catalyst', which covered this very topic, and the astronomers all wanted funding to prevent a disaster, but the politicians wouldn't hear of it, using to 'current' realistic options as an excuse. That's where funding comes in.

Maybe a scary meteor shower would be what it would take to wake them up?

Anyway, I hope that somebody comes up with some realistic way to take on an asteroid soon. That'd probably make it easier.


_________________
With the lowly cattle stringing, Clancy rides behind them singing For the drover's life has pleasures That us townsfolk never know.
- AB Paterson; Clancy of the Overflow

<font size=-1>[ This Message was edited by: Lucky on 2002-06-25 04:24 ]</font>

Ummm, no...

First of all, he didn't write "Man out of Time" and second of all, he never claimed that. Crackpots did...



<font size=-1>[ This Message was edited by: Rift on 2002-06-25 13:41 ]</font>

beskeptical writes

"Fortunately, I think the Sloan Digital Sky Survey is going to give us a very detailed picture of the skies. The project is underway. It is an incredible tool that has a 7 degree field of view in great detail due to millions of dollars worth of some fancy digital computer lenses. It will literally be able to scan the entire sky nightly, from my understanding of it. And, since it will be on an orbiting satelite, it shouldn't miss a hemisphere. (If any of you much better informed astronomers are aware of the actual details, please correct any misunderstandings of the project that I may have.)"

Unfortunately, the SDSS is not equipped to searching for NEOs, although we do find some in the data.

The SDSS uses a 2.5 meter telescope at Apache Point Observatory in Sunspot, New Mexico. Can't see the whole sky. The field of view is 3 degrees, still very large for a telescope, and it takes near simultaneous images through five filters ranging from 3800 Angstroms to 9200 Angstroms (there is a ~17 second delay between images due to the fact that the telescope drift scans). The SDSS will iamge ~10,000 square degrees over the course of five years.

The telescope only takes a single image of each part of the sky. You need multiple images to calculate an orbit. Therefore, although the SDSS finds many asteroids (over 10,000 in the Early Data Release covering ~500 square degrees) there is no way of calculating the orbits of newly discovered asteroids. There have been some proposals to try and do rapid follow up observations to try and recover imaged asteroids, but that is difficult due to the length of the data processing pipelines and no one has the time to dedicate to this project.

But that is not the mission of the SDSS. The SDSS focuses on the large scale structure of the universe, not solar system objects. The telescope and survey strategy were designed to reflect this goal.

You may have heard about the LSST (Large Synoptic Survey Telescope), a proposed 8.4 meter survey telescope with a 7 degree field of view. It does have near earth objects as one of its science projects. Unfortunately, it is still in the planning stages. You can find out about it at

http://www.dmtelescope.org/lssto/

The SDSS site is

http://www.sdss.org

and you can access the Early Data Release at

http://skyserver.sdss.org

Hope this helps.

Rob

Thanks for the clarifications. I'm sure I have a lot more intermixed data in my head. So we still have the big problem of blind spots after all.

You can almost guarantee the politicians are the least likely place to get funding for long term gain issues. They usually only want to look good for the next election.

What we do need, in my infinitely wise opinion, [img]/phpBB/images/smiles/icon_biggrin.gif[/img] is to get the politicians to understand the benefit of using scientific research to make better policy decisions.

Of course it wouldn't hurt to have some major impact occur on a nearby planetary body, but that's wishful thinking. The Shoemaker-Levy 9 event was probably too abstract for the average person to imagine a similar event on Earth. And Tunguska memories are too distant.

Wait, that's it. We need tours to Siberia. Even a virtual flyover might do. And, you could superimpose the site over your favorite city. You could add Arizona's Barringer Crater and many many more. Finally, include a time line with the usual 'this event every 100 years, this one every 10,000' etc.

Nah, people don't even wear seat belts or change batteries in their smoke alarms for more than a week or two after an encounter with a related preventable tradgedy. We best hope for the astronomical community to stay on top of the situation.

I'd say universities and amateur astronomers are a better bet to get results faster for NEO watches.

This just popped into my head. Doesn't the USA have something along the lines of FEMA - Federal Emergency Management Agency? (I've no idea if the UK has anything similar). Wouldn't their charter/remit/mission statement include statements along the lines of " - planning for a major disaster"? And would not an asteroid strike count as just that?
Which is all leading to the question: does or did the FEMA carry out any such planning involving the impact of an asteroid? if they have done or will do then this ought to impress governments - a coldly factual report from an official agency about an actual, undeniable threat to the US (and by extension all the rest of us).

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Garlic Bread?!?!

Cheers, Grapes. Nice little story, that one -and now I know how to spell the man's name [img]/phpBB/images/smiles/icon_smile.gif[/img] .

JB

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Nowhere in all space or on a thousand worlds will there be men to share our loneliness. ...in the principles of evolution we have had our answer: of men elsewhere... there will be none, forever. - Loren Eisely, The Immense Journey, 1956.