Q&A: Will We Ever Clear That Space Junk? and more...
In this week's questions show, Fraser wonders how we're ever going to clear all that space junk orbiting Earth, whether it's better to colonize Mars or Mercury, and can water worlds explain the Fermi Paradox?
Q&A: Will We Ever Clear That Space Junk? and more... (YouTube)
Comments (6)
Fraser, I hate to do this to ya. I really do! I came across the following on Planet X. Yeah, I can hear you groan all the way down here in Georgia! ;~) I honestly haven't read that much on the subject since I've heard your and other folks from the scientific community views on it. But, this article maintains that scientists back in the 50's discovered that Sol is a binary, with a brown dwarf sister that has a planetary system. Yeah, couple of problems there -- brown dwarves are, umm, a wee bit tough to see and (I thought) the first evidence we uncovered of extra-terrestrial planets occurred back in the 90's (or later). The article also claims that there is a large Planet X that is in a 3,600 year orbit about Sol. Well, if brown dwarf stars are tough to see, lone planets out in the Oort (or beyond) gotta be even tougher. As unlikely as all this appears, what do you know about these ... scientists ... back in the '50's research??? <a href="https://thedailyconspiracy.com/2018/01/10/is-planet-x-nibiru-for-real/" rel="nofollow noopener" target="_blank">https://thedailyconspiracy.com/2018/01/10/is-planet-x-nibiru-for-real/</a>
Ahhh, Fraser, answer a question, create a question! You mention that the Sun will shed some layers when it blows up into a red giant, thereby losing mass. Less mass means less gravitational attraction to Earth. Hence, Earth should migrate outward. Scientists aren't sure if the red giant will expand enough to gobble up the Earth -- sounds like it might be a close thing. I would like to say they have no doubt factored in the aforementioned mass loss effects, but I figure you'd likely know for sure.
Were humans to stop managing the orbits of geostationary satellites, for what period of time would they stay in orbit?
Once GEO birds run completely out of fuel, they start drifting towards one of two "graveyard" points above the Earth (one near the East coast of Africa, the other near Indonesia due to the fact that Earth's geoiod is not perfectly spherical). Space is big, but if we just let all of them run out of fuel & drift into these spots, eventually there will be collisions, scattering debris throughout the equatorial ring within months to years depending on one's math. No more Direct TV or GOES weather info! Oddly, most things in lower orbits (GPS, e.g.) won't notice for millennia since the debris will generally stay thousands of km above before spreading out in a Saturn-style ring, but our interplanetary missions would most likely need to start using polar escape vectors thanks to the orbital ring of debris. Most of that debris would stay up there for many, many thousands of years, eventually either being tugged away from Earth by the Moon &/or Sun, or more rarely, deorbited due to change in orbits caused by collision, solar wind, etc. This is why defunct GEO birds are usually placed in an even higher orbit with the last of their remaining fuel, rather than taking up/endangering valuable equatorial orbital slots with their presence. Those orbits are stable for millions of years (barring Sun/Moon interaction) & will eventually allow either for salvage & reclamation once tech advances enough to make it worthwhile, or else the satellites will get spun off harmlessly into space. (edit: formatting)
When the Earth formed, it formed from left over stuff from the sun forming. So, the space junk, on a long enough timeline... won't it just be reabsorbed by Earth?
Yep! The problem is that anything above ~1000 km has an orbital lifetime measured in centuries, while equatorial GEO birds will be there for tens to hundreds of thousands of years. . . much longer if it weren't for the Sun & Moon tugging on them. That's one of the reasons orbital debris vs spacecraft is different from birds/hail/etc. vs aircraft: orbital debris sticks around for a while, even in low orbits.