Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: neilep on 26/02/2009 18:00:49

Title: Where Does The Atmosphere Stop & Space Begin ?
Post by: neilep on 26/02/2009 18:00:49
Dearest Beginspaceologists,

Space is my all time favourite thing that the Earth and other stuff lives in. It's like ...well big !...even bigger than a big thing !!...and that's big !

As a sheepy I of course know all that there is to know about the wonders of Space...one merely has to look inside my ear with one of those doctors ear thingys and ewe will see plenty of it in there. So, though I may be an authority on space, this is one query that eludes me.

Look , here's a planet called Earth and it is surrounded by ' Space'. I have labelled them so that ewe can differentiate the two :


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Nice eh ?..being delivered as a hanging mobile next Tuesday .

What I would like to know is Where does the spacey stuff begin and the atmospherey stuff stop ?  Is it a matter of like crossing a line ?..one step forward I'm floating in space, one step back I'm enjoying friction fun ?


As a firm believer in empirical study I snuck into where my neighbour is resting in hospital and launched him space bound. Boy, did I have to use a lot of gaffer tape to stick him to my rocket..I'll invoice him for that !...anyway, until he returns with hopefully an answer I wonder if ewe can assist me........( i did stick a ruler up his bum so that he could measure it for me !! )



Hugs & Shmishes



mwah mwah mwah




Neil
There's An Echo In My Head !
xxxxxxxxxxxxxxxxxxxxxxxxxxx









Title: Where Does The Atmosphere Stop & Space Begin ?
Post by: lyner on 26/02/2009 18:21:58
I should say that Space begins just above the level of the grass (for a sheep) - or possibly just above its head.
Title: Where Does The Atmosphere Stop & Space Begin ?
Post by: lightarrow on 26/02/2009 18:43:38
What I would like to know is Where does the spacey stuff begin and the atmospherey stuff stop ?  Is it a matter of like crossing a line ?..one step forward I'm floating in space, one step back I'm enjoying friction fun ?

It's a good question. There isn't a line, of course, the atmosphere fades in the void without separation. Maybe we could say that it finishes where conventional airplanes can't fly anylonger...  [:)]
Title: Where Does The Atmosphere Stop & Space Begin ?
Post by: Vern on 26/02/2009 19:57:42
Quote from: Google
As the atmosphere has no abrupt cut-off, but rather thins gradually with increasing altitude, there is no definite boundary between the atmosphere and outer space. 75% of the atmosphere exists within 11 km of the planetary surface. In the United States, persons who travel above an altitude of 50 miles (80 kilometres) are designated as astronauts. The FAI defines spaceflight as over 100 km. 400,000 feet (75 miles or 120 kilometres) marks the boundary where atmospheric effects become noticeable during re-entry. The altitude of 100 kilometres or 62 miles is also frequently used as the boundary between atmosphere and space.

Looks like you officially are an astronaut if you venture above 50 miles.
Title: Where Does The Atmosphere Stop & Space Begin ?
Post by: lyner on 27/02/2009 07:59:38
The region where the 'sky' starts to go black could be thought of as the start of space.
Another practical criterion could be the lowest point at which the atmosphere is rarified enough to allow an orbit to be sustained. ("For how long?", I hear you cry. Let's say thousands of orbits)
Title: Where Does The Atmosphere Stop & Space Begin ?
Post by: yor_on on 27/02/2009 16:58:13
In fact I'm glad you asked.
I have a certain expertise in this matter, ah, space that is..

It starts just over ny shoulders, and I'm pretty sure it ends somewhere over my topmost follicle's?
Title: Where Does The Atmosphere Stop & Space Begin ?
Post by: Don_1 on 27/02/2009 17:34:27
Here is where space begins
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