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Argos
2002-Jan-07, 10:38 AM
The asteroid 2001 YB5 flew by Earth some 300.000 miles this morning. We were unaware of it in November. It could have upset us a lot in this early January. This thought sends a shiver down my spine. The question is: are we really sure that the chances for a collision are as low as it has been heralded?

Dr Benny Peiser of Liverpool John Moores University told BBC News Online: "The fact that this object was discovered less than a month ago leads to the question of if we would have had enough time to do anything about it had it been on a collision course with us"

Are we sure of the statistics related to the near Earth asteroid population?

<font size=-1>[ This Message was edited by: Argos on 2002-01-07 05:40 ]</font>

David Hall
2002-Jan-07, 12:15 PM
Well, let's see. So far we have a list of 359 potentially hazardous objects (YB5 is included).

http://cfa-www.harvard.edu/iau/lists/Dangerous.html

It looks like this list is constantly being updated. At least one new entry from 2002 is already on the list.

I tried to count how many were discovered in each year. Here's my quick tally:

77 in 2001
73 in 2000
48 in 1999
53 in 1998
108 discovered before 1998

So it's only been in the past 5 years that we've even been able to get any idea how many objects are out there. I think it may be a few more years before we are really able to say for sure what the risk is. But for now we seem to be finding about 1-2 new objects per week. When the tally starts to go down again, then I think we can be pretty sure there's not many more out there.

Now as to the actual risks they present, the next page shows the future close encounters with these known objects (up to 2178). Only one of them is predicted to come within lunar orbit distance during that time--in 2140 (But at 0.00079 AU=119,648km, it's pretty darn close!).

http://cfa-www.harvard.edu/iau/lists/PHACloseApp.html

So, in my opinion, there's probably quite a bit more out there to be discovered, maybe 2-3 times what we know so far (my guess), but I don't think the chances of a collision are much higher than we already predict. Hey, we've been lucky so far!

Here's another list of upcoming close encounters listed by date:

http://neo.jpl.nasa.gov/

The last page I'm linking to isn't so directly related, but I think it's so cool I have to post it. It's a plot of the current locations of all inner-system asteroids.

http://cfa-www.harvard.edu/iau/lists/InnerPlot.html

Boy there's a lot of garbage out there. I think the plots of Jupiter's trojan asteroids is the most interesting. I didn't realize they were that dispersed.

GrapesOfWrath
2002-Jan-07, 04:43 PM
You are right, David, that last link is awesome (in the old sense). Old Sol starts to resemble a large version of Saturn, doesn't it?

ToSeek
2002-Jan-07, 05:12 PM
On 2002-01-07 07:15, David Hall wrote:
The last page I'm linking to isn't so directly related, but I think it's so cool I have to post it. It's a plot of the current locations of all inner-system asteroids.

http://cfa-www.harvard.edu/iau/lists/InnerPlot.html

Boy there's a lot of garbage out there. I think the plots of Jupiter's trojan asteroids is the most interesting. I didn't realize they were that dispersed.



It looks terrifyingly crowded out there!

Russ
2002-Jan-07, 07:33 PM
On 2002-01-07 05:38, Argos wrote:
Are we sure of the statistics related to the near Earth asteroid population?

<font size=-1>[ This Message was edited by: Argos on 2002-01-07 05:40 ]</font>

The only things that are sure are death and taxes and we're not so sure about death. /phpBB/images/smiles/icon_wink.gif

My favorite evaluation of this situation is from the late Gene Shoemaker "I think we'll learn about the astroid that's going to kill us all when it enters the atmosphere." I saw him say that on a History Channel show about the KT extinction.

I think his point is that we will probably be hit by some exo-solar-system junk that we'll never have an orbit on. With any luck at all, I'll be at ground zero for that impact.

Azpod
2002-Jan-08, 02:15 AM
On 2002-01-07 14:33, Russ wrote:

My favorite evaluation of this situation is from the late Gene Shoemaker "I think we'll learn about the astroid that's going to kill us all when it enters the atmosphere." I saw him say that on a History Channel show about the KT extinction.

I think his point is that we will probably be hit by some exo-solar-system junk that we'll never have an orbit on. With any luck at all, I'll be at ground zero for that impact.


What a way to go! /phpBB/images/smiles/icon_smile.gif Seriously, though, if we thought the chances of impact with a NEO was remote, impact with a chunk of interstellar debris large enough to wipe us all would be vanishingly rare!

Still, I'd like to be kickin' it on a beach on a terraformed Mars on that day...

Russ
2002-Jan-08, 03:37 AM
Seriously, though, if we thought the chances of impact with a NEO was remote, impact with a chunk of interstellar debris large enough to wipe us all would be vanishingly rare!


OK, lets say the chances are a 100 trillion to one. The nasty thing about probability is, that one chance is just as likely to be in the one or two position as anywhere else.

So at this minute, that rock could be 10 hours out.

Argos
2002-Jan-08, 10:24 AM
On 2002-01-07 07:15, David Hall wrote:
Well, let's see.


Thanks, David. I'll need some time to surf all this dense material. Very good.

Argos
2002-Jan-08, 10:31 AM
On 2002-01-07 14:33, Russ wrote:

With any luck at all, I'll be at ground zero for that impact.


Me too. A last glorious sight before death.

ToSeek
2002-Jan-08, 01:27 PM
On 2002-01-08 05:31, Argos wrote:


On 2002-01-07 14:33, Russ wrote:

With any luck at all, I'll be at ground zero for that impact.


Me too. A last glorious sight before death.




Nah, I want to surf the huge tidal wave that gets created, like in Lucifer's Hammer. /phpBB/images/smiles/icon_wink.gif

Mnemonia
2002-Jan-08, 04:13 PM
On 2002-01-07 12:12, ToSeek wrote:


On 2002-01-07 07:15, David Hall wrote:
The last page I'm linking to isn't so directly related, but I think it's so cool I have to post it. It's a plot of the current locations of all inner-system asteroids.

http://cfa-www.harvard.edu/iau/lists/InnerPlot.html

Boy there's a lot of garbage out there. I think the plots of Jupiter's trojan asteroids is the most interesting. I didn't realize they were that dispersed.



It looks terrifyingly crowded out there!


Ermm.. Map most definately not to scale /phpBB/images/smiles/icon_smile.gif

Chip
2002-Jan-08, 04:32 PM
On 2002-01-08 05:31, Argos wrote:


On 2002-01-07 14:33, Russ wrote:

With any luck at all, I'll be at ground zero for that impact.


Me too. A last glorious sight before death.


That's a bit too "kamakazi." If I have a choice, I'd prefer an invitation to Azpod's surf party on Mars! /phpBB/images/smiles/icon_wink.gif

Roy Batty
2002-Jan-08, 04:57 PM
On 2002-01-08 08:27, ToSeek wrote:

Nah, I want to surf the huge tidal wave that gets created, like in Lucifer's Hammer. /phpBB/images/smiles/icon_wink.gif


Make sure you keep out of the way of 'bugblatter' buildings then /phpBB/images/smiles/icon_smile.gif

Argos
2002-Jan-08, 06:09 PM
On 2002-01-08 11:32, Chip wrote:

That's a bit too "kamakazi." If I have a choice, I'd prefer an invitation to Azpod's surf party on Mars! /phpBB/images/smiles/icon_wink.gif


That would be cool!:lol:

Argos
2002-Jan-08, 06:13 PM
On 2002-01-08 08:27, ToSeek wrote:


Nah, I want to surf the huge tidal wave that gets created, like in Lucifer's Hammer. /phpBB/images/smiles/icon_wink.gif


It would be a helluva ride. Unfortunately, too radical for a country boy like me...