Meteor nearly hits sky diver. Film at 11.

Wendy

Joined Mar 24, 2008
23,429
I saw that video on MSN. That person should go out an buy lottery tickets, the odds are much better.

Funny thing, if they do find that rock it will be worth about its weight in gold.
 

THE_RB

Joined Feb 11, 2008
5,438
Why would a meteor do 300 mph? They enter the atmosphere doing thousands of mph. And if it had lost enough energy from friction to slow it to 300 (very unlikely) that would be absorbed as heat in the meteor so with a low mass meteor there would be nothing left, and a high mass meteor could not have slowed to 300.

A smooth object (like a rock) dropped from a plane would do about 300 mph.
 

GopherT

Joined Nov 23, 2012
8,009
Why would a meteor do 300 mph? They enter the atmosphere doing thousands of mph. And if it had lost enough energy from friction to slow it to 300 (very unlikely) that would be absorbed as heat in the meteor so with a low mass meteor there would be nothing left, and a high mass meteor could not have slowed to 300.

A smooth object (like a rock) dropped from a plane would do about 300 mph.
That is why I finished with "...supposedly".

The news/web reports all seem to quote a 300kmh speed in Europe and 300mph speed in the US. I don't know where that number comes from.

I just found that terminal velocity of a meteor after deceleration is 100 m/sec

Also, the jump occurred in June but was posted in April 3. I think he just had trouble finishing his April fools joke on time. We will hear the real story in the next few days.
 
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t06afre

Joined May 11, 2009
5,934
A meteor often explode the it reach the more dense part of the atmosphere, 2 to 4 metric mile above sea level. Then meteor pieces will then reach a speed in range of around 200 Km/h. On their way to the ground
 

GopherT

Joined Nov 23, 2012
8,009
OK, now that it is not 5am and I've had my coffee, the conversion of 100 m/sec is about 225 mph. So the AMS states meteor fragments fall at 100 to 200 m/sec so that equates to 225 to 450 MPH (300 in round numbers).

Never mind - the news stories are essentially right, maybe it did happen!


See AMS page (right near the top as page displays)
http://www.amsmeteors.org/fireballs/faqf/#8
 

THE_RB

Joined Feb 11, 2008
5,438
Yeah that's the speed for a dropped object.

So a meteor somewhere above him exploded (but nobody saw or heard that?), then one piece from the explosion fell past him at the same speed as a dropped object, and just missed his jump plane that was above him...
;)
 

GopherT

Joined Nov 23, 2012
8,009
I thought terminal velocity is terminal velocity, the point where air friction equals gravitational pull. Anything falling faster will decelerate and anything falling slower will accelerate until each reaches terminal velocity - assuming there is enough time to reach terminal velocity.

I've seen a video of two skydivers, one dropping baseballs and one throwing a baseball downward. The thrown baseball immediately slows and falls just a few feet ahead of the dropped ball. Whether thrown or dropped,
 

THE_RB

Joined Feb 11, 2008
5,438
I thought terminal velocity is terminal velocity, the point where air friction equals gravitational pull. Anything falling faster will decelerate and anything falling slower will accelerate until each reaches terminal velocity - assuming there is enough time to reach terminal velocity.
...
Time is the key. A meteorite is made of iron or stone or some mix, so it has very high mass/volume, and it is travelling at incredibly high speeds when it hits the upper atmosphere.

From my understanding it would be incredibly rare for a meteorite to hit the ground at terminal velocity, they normally impact the ground at very high speeds. Unless it blew up in the air (like people have said), and some pieces then had lower velocities than the original projectile.

Anyway, all common-sense sepculating aside I give it about 90+% odds that this is just an april fools prank. So easy to do when a skydiver always has a plane above him while he is falling. Just chuck something out the plane and film it. :)
 

GopherT

Joined Nov 23, 2012
8,009
Anyway, all common-sense sepculating aside I give it about 90+% odds that this is just an april fools prank. So easy to do when a skydiver always has a plane above him while he is falling. Just chuck something out the plane and film it. :)
I am a very skeptical person and I've been suspicious from the first day I heard this story. I have found some additional commentary and analysis...from pretty credible people. It is not my job to convince anyone but, I am leaning towards true.

http://www.universetoday.com/110963...it-by-falling-meteor-and-captures-it-on-film/


http://www.slate.com/blogs/bad_astr...eo_of_a_skydiver_almost_hit_by_meteoroid.html
 

tcmtech

Joined Nov 4, 2013
2,867
If anyone did a bit of followup searching a meteor was tracked into their area and exploded at the same time and in the same location so a falling fragment coming that close could have been possible.

BTW the plane is not right above them. When you jump your relative motion and vector from the aircraft quickly changes from horizontal to vertical but the plane direction and velocity stays the same horizontal and going away because is still in powered flight thus after the first few seconds it is now nowhere near being above you.

Didn't anyone pay attention in physics class? :confused:
 

DerStrom8

Joined Feb 20, 2011
2,390
BTW the plane is not right above them. When you jump your relative motion and vector from the aircraft quickly changes from horizontal to vertical but the plane direction and velocity stays the same horizontal and going away because is still in powered flight thus after the first few seconds it is now nowhere near being above you.

Didn't anyone pay attention in physics class? :confused:
I may be misunderstanding you, but you will have the same horizontal velocity as the plane did when you left it. Therefore, assuming your horizontal velocity does not decrease and the plane's horizontal velocity does not increase, it will remain above you until one or the other changes. You will eventually create enough drag to slow down your horizontal speed, but for a time the plane will not appear to be moving at all in relation to you.
 

Thread Starter

ErnieM

Joined Apr 24, 2011
8,377
I may be misunderstanding you, but you will have the same horizontal velocity as the plane did when you left it. Therefore, assuming your horizontal velocity does not decrease and the plane's horizontal velocity does not increase, it will remain above you until one or the other changes. You will eventually create enough drag to slow down your horizontal speed, but for a time the plane will not appear to be moving at all in relation to you.
I understanding tmctech, you will have the same horizontal velocity as the plane did when you left it, but your horizontal velocity will decrease as the plane's horizontal velocity remains constant, it will quickly pull ahead of you.

You instantly create enough drag to slow down your horizontal speed, that's why jumpers are more afraid of hitting the plane they just jumped out of then hitting the ground.
 

DerStrom8

Joined Feb 20, 2011
2,390
I understanding tmctech, you will have the same horizontal velocity as the plane did when you left it, but your horizontal velocity will decrease as the plane's horizontal velocity remains constant, it will quickly pull ahead of you.

You instantly create enough drag to slow down your horizontal speed, that's why jumpers are more afraid of hitting the plane they just jumped out of then hitting the ground.
I see what you're saying. I have never been skydiving (unfortunately) so I wasn't sure how quickly the drag would slow you down.

Thanks for clearing that up.
Matt
 
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