New ISS footage from 1st May reveal more UFOs

Originally posted by MarioOnTheFly
reply to post by JimOberg

 

Hey Jim, got one question for you, since you are a scientist. About space junk...i'm sure i'm missing some vital piece of knowledge...since it is deffinately not my arena...but...

why is space junk floating so close to earth? shouldn't it be pulled slightly towards earth and eventually it should crash through the atmosphere and probably burn up. I just don't get what is holding the junk up there? It probably has some inertia obtained during the procedure that "ejected" or propelled it....but how long can it keep it's orbit without any engines or thrusters or something to keep it from being pulled towards earth?

And if the junk is moving...how log can it sustain it's momentum?...I realize it's vacuum out there's and no air resistance...is it really staying that long out there? I would assume that all objects that circle the earth are well within the sphere of influence of earth gravity or am I mistaken?

I'm kinda going by my cartoon logic without any actual space motion physics knowledge, so pardon my ignorance.


thanks
Mario

The only way things stay 'in orbit' is due to tremendous speed, which counteracts the inexorable pull of gravity by literally throwing the object 'over the horizon' so that even though it is always falling 'down' towards Earth, Earth's surface is receding beneath it [round planet effect] at about the same rate.

When air drag slows it down -- you're exactly right on this -- it doesn't quite 'make it' over the horizon, and begins skimming thicker and thicker layers of the atmosphere. That slows it even more and it drops even more, soon hitting serious resistence. Finis.

The lower the altitude, the thicker the thin air. At space station altitude, it loses about 50 meters per day in altitude from drag effects, and needs periodic reboosts. BUT junk is less dense so drops even more quickly, and the orbits near the station are relatively scrubbed compared to thicker zones higher up. But those orbits are also inside the van allen radiation belts so living things are already unwelcome there.

I've tried to compile a lot of space operational explanations in my "99 FAQs on 'Space UFOs'" essay, so people have a stronger background in evaluating strange videos from space -- some of which I have no doubt are of interesting, even dangerous, origin. But one has to weed them out, and the youtube posters never do.

reply to post by JimOberg


So If I understand you correctly, this space junk that "we" generate should very quickly succumb to earth gravity and eventually drop down to earth?

This is what I don't get...how come there's plethora of these things flying up there. On every "space" video...there is apparently loads of it...flying around. How come? Are these videos always filmed right after creating/ejection of this junk? And how come it is increasing? Increasing how? Doesn't it all fall back to earth eventually?

edit:
didn't want to create aditional posts, but you mentioned Van Allens Belt and how it's not hospitable to living things. Your take on it? can a human being pass through the belt at speeds available to us and escape unharmed, without some extensive shilding?

Thanks

Originally posted by MarioOnTheFly
reply to post by JimOberg

 

So If I understand you correctly, this space junk that "we" generate should very quickly succumb to earth gravity and eventually drop down to earth?

This is what I don't get...how come there's plethora of these things flying up there. On every "space" video...there is apparently loads of it...flying around. How come? Are these videos always filmed right after creating/ejection of this junk? And how come it is increasing? Increasing how? Doesn't it all fall back to earth eventually?

This is why i created the "99 FAQs" -- here's an excerpt:

35 Q: How much of it is “space junk”?

A: Very, very little, actually – if you use the standard definition of “space junk” to mean other satellites and pieces off of them, which constitute an impact hazard to human space missions and automated satellites as well. Because all orbiting objects are moving at tremendous speeds in different directions, when they do pass closely to each other, they zip past at several miles per second. Thus they are extremely difficult to detect visually. Anything that was seen over a period of time longer than a few seconds would have to have been something closely following the observer, and thus associated with the vehicle from which the observation was being made. Now, that's unless it was somebody else’s vehicle deliberately keeping pace, of course. But "space junk" as we commonly use the term? Hardly ever, maybe never.



36 Q: How often do astronauts see passing satellites out the window, or on TV screens.

A: Astronauts have observed other distant satellites, but not often. On special research programs, some astronauts have been able to spot ‘Iridium flares’ [Don Pettit, for example]. But on occasion when the crew was advised to look for a particularly close [a few miles] pass of a large satellites, every effort to detect the fly-by visually has failed. I have never found a single case of an observed nearby object turning out to be a passing satellite in independent orbit.



37 Q: But aren’t they flying through clouds of ‘space junk’? How could all those tens of thousands of objects be invisible?

A: I’ve got to admit that this has been really surprising to me since like so many others I had at first overlooked how big space is and how FAST criss-crossing orbits diverge. The earthside analogy of airplanes on different headings being visible to each other in midair as they crossed paths just overwhelmed a rational consideration of the way space is so very different, so unearthly. It makes sense now that eyeballs would almost never notice such fast passersby, so I can understand how the public has fallen for the same false analogy.



38 Q: Don’t astronauts keep a visual or radar watch out for approaching satellites in order to dodge a possible collision?

A: Surprisingly, no. At the relative speeds of objects in space, objects would only be detectable [if at all] within a few seconds of impact. Collision predictions are made hours or days in advance because much more powerful ground radars observe and catalog everything in orbit, and powerful computers predict their future flight paths to see if they may soon get close enough to threaten collision. The shuttle’s Ku-band dish antenna was mainly used for communications via relay satellites, but it could operate in a ‘skin-track’ mode for taking navigation ‘marks’ on a target satellite for a rendezvous or separation – but only at a range inside about 10 miles. And when using the antenna for tracking, it could not be used for data or video relay. There is no radar tracking capability on the ISS.

40 Q: If not from existing swarms of ‘space junk’, where does this stuff come from?

A: I think the overwhelming majority of real ‘stuff’ seen by astronauts or via television or film [motion and still] is derived directly from the vehicle they happen to be aboard. I call it ‘dandruff’ to differentiate it from ‘space junk’ – which I do NOT think accounts for any of these notorious sightings..

thanks for the excerpt. Maybe I missed it but it didn't really answer my question: why doesn't it all fall down to earth? How can it be increasing up there ? Maybe I'm wrong but I don't see how we can produce more junk up there than the earth can attract down?

Beautiful footage of earth from ISS, I see the earth and horizon.....a few stars and some space debris / ice etc zipping by in zero gravity, catching the suns reflection.

Thanks for posting.

reply to post by MarioOnTheFly
He's saying, basically...
Depending on the weight of a single piece of junk, and its distance from the earth, their is a perfect speed that it can travel to stay in orbit.
I think (correct me if I'm wrong) but that speed is around the same speed that the space shuttle or rocket is traveling when it leaves the earths atmosphere. So to me it makes sense to have alot of junk up there. Before it becomes that junk its already going around the speed it needs to be to stay in orbit. Also, I would imagine a lot of the junk is going too fast to be drawn into the atmosphere, essentially that junk would be spiraling away from the earth.

I'd also like to ask this, because I heard it somewhere when I was younger and I can't remember where I heard it.
It might not even be a reality but,
Is it true, that eventually there will be enough junk in space, that it will form a ring around the earth, on its own?

TXML

Looking at the first link, at 1:30, just looks like a rock spinning. The other ones before, didn't really look like anything that shouted UFO.