PDA

View Full Version : Meteors and Fireballs



Bruce Keefe
2002-Sep-04, 03:40 AM
Hi All!
Philip Plait stated that meteors are pretty cool (temp wise) when they hit the ground when he wrote up 5 misconceptions at: http://www.space.com/scienceastronomy/top5_myths_020903-5.html

My question is thus; does this apply to "fireballs"?

I witnessed a fireball in 1983 that flew over Ridgecrest, Ca. at about midnight. It was a BIG ball of fire that sailed over the town, then impacted on the range of hills to the north of town. This impact started a fire. Unfortionaly, the impact area was on the China Lake Navel Weapons Base enclosure, so I could not get to the site for a sample /phpBB/images/smiles/icon_frown.gif
It sure seemed to me that the meteor was hot when it hit, so I was very suprised when I read his article. /phpBB/images/smiles/icon_eek.gif

Please explain this to me...

Many thanks,

Bruce Keefe


<font size=-1>[ This Message was edited by: Bruce Keefe on 2002-09-04 13:54 ]</font>

Senor Molinero
2002-Sep-04, 03:58 AM
Austin Powers might be interested in those "Navel Weapons".

GrapesOfWrath
2002-Sep-11, 05:29 PM
On 2002-09-03 23:40, Bruce Keefe wrote:
My question is thus; does this apply to "fireballs"?

It may be a question of semantics--the meteorite is not going to heat up much, according to the BA. But the meteor--the burning light that we can see--might make it to the ground. He says most of that heat is compressed air, not hot rock.

grewwalk
2002-Sep-24, 07:51 AM
I've done my own experiments using torches (oxy-acet, nice and hot!) on some different kind of regular rocks here on earth.

It seems while the surface would heat up to very high temps, the heat did not conduct easily underneath. The surface would cool rather quickly.
If I broke off the hot part, just shortly underneath, it would be reletively cool.

These were just simple experiments with rocks around the yard albiet low iron content, but it did give me a good impression that the heat just did not conduct very well. Especially with the limited time that a meteor had spent burning through the atmosphere.

GrapesOfWrath
2002-Nov-17, 12:28 PM
The APOD for Nov. 18, 2002 (http://antwrp.gsfc.nasa.gov/apod/ap021118.html) (sorry, nebularain) (http://www.badastronomy.com/phpBB/viewtopic.php?topic=2849&forum=2) has a nice photo of The Peekskill Meteor Car, with the meteorite that hit it in 1992, on the ground beside it. It warns "If you are lucky enough to find a meteorite just after impact, do not pick it up -- parts of it are likely to be either very hot or very cold"

<font size=-1>[Fixed url, typo]</font>

<font size=-1>[ This Message was edited by: GrapesOfWrath on 2002-11-17 09:42 ]</font>

nebularain
2002-Nov-17, 04:28 PM
LOL!
Guess I'll have to wait a day....

amcheetham
2003-Jan-15, 10:00 PM
Having started to read the book, I have noted the first mistake :

With regard to the claim (Page 31 of the book) that the use of "meteoric rise" can not be used to describe a rising political star, I would like to suggest that this is not a case of bad astronomy by the press
and public, but rather a case of a lack of understanding of language by yourself.

The term METEOR (Collins English Dictionary) derives from the Greek METEOROS meaning LOFTY. This is in turn comes from META an intensifer such as VERY and AEIREIN meaning TO RISE.

Thus this description better suits a rising politician than it does the falling shooting star (though of course there is the whole question of what is up and down in a relative world).



Will continue to read your book and pull you up on the errors contained therein.

David Hall
2003-Jan-17, 05:55 AM
My opinion on the phrase "meteoric rise" is that 'meteoric' refers to the speed of the action, not it's direction. Fast and sudden, just like a real meteor. You could say "meteoric fall" and it's just as understandable, if a bit unusual due to lack of familiarity.

I haven't gotten my hands on the BA's book yet, so if he has addressed this point, let me know.