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orangeSCT
2004-Apr-12, 01:19 PM
Space.com had an interesting article about this site www.lpl.arizona.edu/impacteffects
Kind of cool. Maybe this will help wake a few people up on the importance of near earth object searches. I would hate to be caught off gaurd by even some of the smaller impacts (if it happened to be near enough).

Toutatis
2004-Apr-12, 01:28 PM
Sadly, that utility has 'difficulties' --- Not the least of which is its *woeful* understatement (read flat-out-omission) of sequelae!!! http://www.badastronomy.com/phpBB/images/smiles/icon_evil.gif

Regards
Sarandon

ToSeek
2004-Apr-29, 05:25 PM
ABCNews.com picks up the story (http://abcnews.go.com/sections/SciTech/US/asteroid_collision_040429-1.html)

bmillsap
2004-Apr-29, 08:04 PM
Wait a minute - from the ABC story:

"That means you're 200 times more likely to die in a car crash than by an asteroid strike and 20 times more likely to die by lightning."

Car Crash = 200 x asteroid
Lightning = 20 x asteroid
_____________________
Car Crash = 10 x Lightning?

Gotta be missing a zero or two in there somewhere unless I'm not understanding that sentence correctly.

Eroica
2004-Sep-29, 04:33 PM
The minimum impact velocity on Earth is 11 km/s.
Why? Couldn't an object in a similar orbit to the Earth's "catch up" with us at a very slow relative velocity - like that trick where you catch an egg on a frying-pan without breaking it (the egg, that is!)?

ToSeek
2004-Sep-29, 04:51 PM
The minimum impact velocity on Earth is 11 km/s.
Why? Couldn't an object in a similar orbit to the Earth's "catch up" with us at a very slow relative velocity - like that trick where you catch an egg on a frying-pan without breaking it (the egg, that is!)?

Not if the frying pan accelerates the egg at 9.8 m/s^2 when the egg gets close.

russ_watters
2004-Sep-29, 05:18 PM
The minimum impact velocity on Earth is 11 km/s.
Why? Couldn't an object in a similar orbit to the Earth's "catch up" with us at a very slow relative velocity - like that trick where you catch an egg on a frying-pan without breaking it (the egg, that is!)? Sure, but at some point, the earth's gravity field will accelerate it toward the earth. Starting at just over zero velocity at a high but finite distance away, the impact is at escape velocity: 11 km/sec.

Eroica
2004-Sep-30, 07:33 AM
Not if the frying pan accelerates the egg at 9.8 m/s^2 when the egg gets close. #-o I get it. Thanks.


Sure, but at some point, the earth's gravity field will accelerate it toward the earth. Starting at just over zero velocity at a high but finite distance away, the impact is at escape velocity: 11 km/sec.Ditto.

Ut
2004-Sep-30, 03:01 PM
Yeah, but I somehow expect the terminal evelocity of a giant boulder to be somewhat less than 11km/s.