Wednesday, October 22, 2014

Reality check: UFO spotted on spacewalk video

Here's the picture that is supposed to electrify us (AOL site):  the yellow arrow is mine:

Yup, the arrow is supposed to point  to a "UFO". Maybe, but probably not.

You see, there's a tiny source of difficulty when attempting to spot UFOs out the window of one's orbiting spacecraft.

Anything that breaks off one's orbiting spacecraft does NOT  fall away into deep space. Why not? Because  it has exactly the same momentum and velocity as the spacecraft itself, assuming it's simply "fallen off", as distinct from being blasted off in an explosion.

That being the case, it simply accompanies one, orbit after orbit, forever on view outside the window. That's due to lack of air resistance (no air resistance in space) and because gravity in orbit, while still acting, causes objects that have been placed into orbit to go into "free fall" AROUND the Earth instead of downwards towards the Earth (even the young Newton was able to figure that out some 350 years ago). You and your space craft's cast-offs are forever enjoined, unless or until you do something to slow the junk down, speed it up, or attach something (a gas cylinder etc) that sends it off into a different orbit.

You could try blowing it up, but some of the fragments would  probably follow you on your orbit.

All that accompanies one in orbit is not necessarily a UFO. It may be your contribution to space junk.

Speaking of which:

Watch: Russian cosmonauts jettison unneeded antennas on successful spacewalk

Headcam footage shows two russian cosmonauts floating outside the International Space Station on Wednesday on a six-hour spacewalk 



Telegraph article, 23 October 2014

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