It would be disappointing, to say the least, to travel ten million kilometers only to find it's space flotsam.
1) the orbit is locked into a very odd figure-8 pattern that does not seem realistic to be either an artificial satellite launched from Earth or a natural satellite of Earth or asteroid. Taking into consideration [all of the] gravitation and solar forces on the object, this orbital pattern is about as strange as has ever been seen.
2) The mass of the object is very low, and indicates that it is NOT natural "space rock" material, very small for its total volume and size.
further complicatiing things is that the orbit of this unknown object is fairly stable and not subject to orbital "decay" as one would expect from something launched from Earth.
Is it possible that this object could eventually be shepherded into a more stable orbit around the Earth, not by artificial means but just the Earth's gravitational influence, so it becomes a true satellite.
If this asteroid turns out to be a valuable resource type, it might be a candidate for more ambitious missions to actually gradually move the entire thing to a more convenient location in earth-moon Lagrange or lunar orbit.
I bet Planetary Resources has been looking at this one for awhile already.
Its a cool discovery. It would be interesting to know if there are realistic trajectories to reach it with a manned mission (e.g., with Orion or Dragon 2). Given its substantial inclination, I can imagine that there might be other objects which are more accessible in terms of delta-v. Quote1) the orbit is locked into a very odd figure-8 pattern that does not seem realistic to be either an artificial satellite launched from Earth or a natural satellite of Earth or asteroid. Taking into consideration [all of the] gravitation and solar forces on the object, this orbital pattern is about as strange as has ever been seen. Strange claim. This "figure 8 pattern" is only a projection of the orbit onto the Earth's night sky. If you look at the video in the OP link, its a perfectly normal elliptical orbit around the sun. It just happens to be one slightly perturbed by the Earth in a way such that it keeps the Earth company.Quote2) The mass of the object is very low, and indicates that it is NOT natural "space rock" material, very small for its total volume and size. Even more strange claim. I strongly doubt anyone has been able to measure the mass of this object.Quotefurther complicatiing things is that the orbit of this unknown object is fairly stable and not subject to orbital "decay" as one would expect from something launched from Earth.Orbital decay (for satellites) is not a consequence of having been launched from Earth. Its a function of the number of atoms (from the extended atmosphere) encountered by a satellite on its orbital path, and the resulting "drag" force slowing it down. This effect (which applies to natural and artificial objects equally, of course) is important for the first 1000 km or so, and negligible on human time-scales above that. As this new asteroid is even further away than that (way beyond the Moon's orbit), this is a complete non-issue here. QuoteIs it possible that this object could eventually be shepherded into a more stable orbit around the Earth, not by artificial means but just the Earth's gravitational influence, so it becomes a true satellite.It would need to shed some orbital energy for that. Its not impossible, considering e.g. scenarios involving repeated swing-bys with the Moon, but its not very likely. Exemplified by the fact that neither the Earth, nor the other terrestrial planets seem to have such "captured" small satellites.QuoteIf this asteroid turns out to be a valuable resource type, it might be a candidate for more ambitious missions to actually gradually move the entire thing to a more convenient location in earth-moon Lagrange or lunar orbit.At 40-100 m, its likely to be not worth the effort. Perhaps for fuel, if its volatile-rich, or rare metals, if its an iron. Both are relatively unlikely, at ca. 15% and ca. 2%, respectively. Of course, its viability as a resource will also depend on the delta-v needed to reach it. QuoteI bet Planetary Resources has been looking at this one for awhile already.It has only been discovered in April this year. I doubt PR knew about it before anyone else.
I thought Mars's moons were captured asteroids from the asteroid belt?
Also will this object be given a proper name being as it is a semi-satellite of Earth now and for a number of centuries beyond?
Quote from: Comga on 06/16/2016 09:49 pmIt would be disappointing, to say the least, to travel ten million kilometers only to find it's space flotsam.Unless it's flotsam that's not human-made. :-)
Its a cool discovery. It would be interesting to know if there are realistic trajectories to reach it with a manned mission (e.g., with Orion or Dragon 2). Given its substantial inclination, I can imagine that there might be other objects which are more accessible in terms of delta-v. ...
While it's likely to be some natural object, the forces involved in its' orbit, seem to make that highly unlikely to be of natural origin.
Regarding delta-v and accessibility, there are certainly others with better specific launch opportunities, but in terms of total viable opportunities it's pretty high on the list. NHATS shows a large number of viable round-trips for <7km/s from LEO to re-entry, with the lowest energy ones taking about a year.
Spectral and other data will tell if it's a particularly interesting object or not, and improve size constraints if they can get the right IR data - and perhaps radar can tell if it has companions (which would allow one to determine its mass; I'm not sure why it's shown as not observable from Goldstone or Arecibo, since it reaches a decent declination and pointing uncertainty is low) - but for flexibility and ease of targeting it may be quite attractive.
At a size of between 130 to 325 feet, It'd be a pretty safe bet that it ain't one of ours.
Quote from: JasonAW3 on 06/17/2016 01:46 pmAt a size of between 130 to 325 feet, It'd be a pretty safe bet that it ain't one of ours.I'll bet that size is based largely on brightness, though. If's painted white, it's probably smaller than the typical asteroid of similar brightness.
Again, likely a rock, but a pretty weird one.
Does anyone know how the size was determined? Most size calculations use the measured brightness with an assumed albedo, like Proponent said.
I am further confused on this issue when I read in a couple of articles reporting this news that the Earth already has a number of mini-moons, but it was stated up thread that the rocky planets don't collect such moons?
Quote from: Bynaus on 06/17/2016 06:18 amIts a cool discovery. It would be interesting to know if there are realistic trajectories to reach it with a manned mission (e.g., with Orion or Dragon 2). Given its substantial inclination, I can imagine that there might be other objects which are more accessible in terms of delta-v. ...First, thanks Bynaus for all your insightful comments, they are spot on about about what is known about this item.Regarding delta-v and accessibility, there are certainly others with better specific launch opportunities, but in terms of total viable opportunities it's pretty high on the list. NHATS shows a large number of viable round-trips for <7km/s from LEO to re-entry, with the lowest energy ones taking about a year. It can be done even quicker, coming down to <200 days if you can come up with 11+ km/s. What's pretty unique about this due to its quasi-stable relationship with earth is that the windows are open very consistently, for many years, rather than every few years or more as for other low delta-V NEOs. Spectral and other data will tell if it's a particularly interesting object or not, and improve size constraints if they can get the right IR data - and perhaps radar can tell if it has companions (which would allow one to determine its mass; I'm not sure why it's shown as not observable from Goldstone or Arecibo, since it reaches a decent declination and pointing uncertainty is low) - but for flexibility and ease of targeting it may be quite attractive.