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Espritch
2002-Aug-24, 12:35 AM
Today's Charlotte Observer reports that researchers at Stanford and Lousiana State have found evidence suggesting that about 3.47 billion years ago, Earth was hit by an asteroid 12 miles in diameter. By comparison, the one that hit Yucatan 65 million years ago (and is thought responsible for the extinction of the dinosaurs) was only about 6 miles wide. The evidence is glass droplets believed to have condensed from rock vaporized by the impact and a concentrated layer of iridium. The material has been found in both Africa and Australia. According to the article, the impact crater has been erased by geologic forces.

I just noticed, it appears David Hall already posted something about this. Dang.

<font size=-1>[ This Message was edited by: Espritch on 2002-08-23 20:37 ]</font>

Jigsaw
2002-Aug-24, 02:47 AM
'S okay. /phpBB/images/smiles/icon_biggrin.gif

Link to story.
http://www.cnn.com/2002/TECH/space/08/23/ancient.meteorite/index.html

Rift
2002-Aug-24, 03:08 AM
Okay, I have several, probably dumb, questions...

First of all, wasn't the solar system still kind of 'busy' 3.5 billion years ago? Is a 20 mile km asteroid anything to get excited about that early in the history of the solar system. Was there still a lot of junk flying around?

And my second stupid question, wasn't life incrediably simple 3.5 billion years ago? (was it even life?) I don't see how an asteroid, that far back would have the 'significant effect on life' they are talking about. Killed a bunch of bacteria, big deal... /phpBB/images/smiles/icon_smile.gif (I know, somebody is going to bring up "The Sound of Thunder" lol)

I think it's cool they can detect impacts that earlier, but it seems to me that the media is hyping up anything that has to do with asteroids lately...

(Going back to the BA's post in the Planet X folder, I probably should read the primary scientific source and not a media news article, lol)

PS- Just noticed on the AOL start up screen they had a blurb about "Giant Meteroite Nearly Wiped Planet Clean of Life" talk about hype...

_________________
"Ignorance has caused more calamity then malignity" H.G. Wells

<font size=-1>[ This Message was edited by: Rift on 2002-08-23 23:14 ]</font>

xriso
2002-Aug-26, 08:56 AM
On 2002-08-23 23:08, Rift wrote:
Okay, I have several, probably dumb, questions...

First of all, wasn't the solar system still kind of 'busy' 3.5 billion years ago? Is a 20 mile km asteroid anything to get excited about that early in the history of the solar system. Was there still a lot of junk flying around?


It is quite a bit after the heavy bombardment period, so life was definitely around. Life as complex as bacteria, in fact.



And my second stupid question, wasn't life incrediably simple 3.5 billion years ago? (was it even life?) I don't see how an asteroid, that far back would have the 'significant effect on life' they are talking about. Killed a bunch of bacteria, big deal... /phpBB/images/smiles/icon_smile.gif (I know, somebody is going to bring up "The Sound of Thunder" lol)


Yeah, there were probably a lot of bacteria all over the place, and in large populations bacteria is pretty darn resilient. I'm not sure about the numbers but it seems that it would be anywhere from downright nasty to extinction for advanced life.