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Small Asteroid Making 400,000 Mile Pass By Earth
AtariKee writes "Universe Today is reporting that a small 10m asteroid, discovered earlier this month and named 2009 BD, is passing within 400,000 miles of Earth. Although the asteroid poses no threat to the planet, the site reports that the asteroid is still very interesting, as it may be a rare co-orbital asteroid (as in, shares the same orbit as Earth)."
Am I the only one who thinks we should attempt to land on it
Yes! Yes you are.
How do you propose to land on a 10 meter wide asteroid?
Having NEOs in stable orbits around the Earth could be of benefit to mankind in the future as missions can be planned, possibly sending mining missions to these rocky visitors so we can tap their resources.
The Near-Earth-Objects in question are only 10m and 20m in diameter. How would it be of any benefit to us to mine resources from these? Surely it would cost far more in resources to -get- there.
Or do these NEOs have some kind of exotic resource that I am unaware of?
A co-orbital asteroid?? Does this make Earth a Dwarf planet? ;-) Isn't one of the criteria for planet-hood that the body has cleared its orbit of debris?
But a 10 meter diameter rock is a lot of material already in orbit that you don't have to pay propellant to get out of earth gravity well. Whether it is doable to have the refinery above or not is another story. But if you DO have the refinery, then it make a lot of sense to mine those NEO for materials, and use it to expand on existing facility above without to have to lift it all. Naturally it all depends on what type of maetrial you are looking for , and rarity of those NEO.
But if the asteroid and earth are on the same orbit, how exactly does one of those objects "pass by" the other. To invoke the inevitable car analogy, that's like saying two cars driving in the same lane on the highway can pass each other. I think, more likely, the would collide.
Seems to me Earth and the asteroid could be in nearly identical orbits and pass each other, or in the same orbit and never collide so long as they're travelling the same speed (or is it velocity?) but two objects traveling the same path at different speeds don't pass each other.
Well, Moons can be defined a lot of ways. If you look at an orbital plot in a reference frame that rotates with the Earth's orbit (so that the Earth and the Sun appear to be fixed, or nearly so), then these "co-orbitals" may appear to orbit the Earth. So from that standpoint, they appear to be satellites.
I might also point out that from the Sun's point of view the orbit of the Moon (the big one) never appears to actually cross itself as it orbits around the Earth (i.e., as plotted from a Sun fixed frame the Moon's orbit is an S-shaped curve, not a series of loops), so you could say that the "real" Moon is co-orbital too
But, I think that the real purpose of calling these "second Moons" is to get these discoveries into the press, and the tactic seems to be having the desired effect.
If it shares the Earth's orbit, shouldn't its speed, relative to the Earth, be zero?
On average, but not necessarily at any given time.
Various astronomers have pointed out that the Earth and Luna are effectively two small planets sharing an orbit. On average, they have the same orbital speed, but because of their masses, they can't maintain a constant distance apart. For a while, they are accelerating toward each other, slowing down the one that's leading and speeding up the one that's trailing. This makes the leading one drop toward the sun slightly, while the trailing one moves out slightly, and they pass. Then they've changed roles, and the process repeats. From either one of them, it looks like the other is a satellite. And while they both have the same average orbital speed around the sun, at any given time both have an instantaneous speed that's slightly different from that average.
There's a similar pair of moons in the Saturn system, that share an orbit and are repeatedly swapping the leading/trailing positions. Actually, this effectively happens with any planet-moon pair, but in cases like Mars or Jupiter, where the satellites are many orders of magnitude smaller than the planet, the effect on the planet can't be detected because the planet's changes of orbital speed are too small to be measured by our instruments.
This new object could be compared to the Earth's moon, but it's a lot smaller and is in a much wider orbit. Or all three could be considered objects with nearly-identical orbits around the sun, constantly swapping leading/trailing roles.
Similarly, I once read a description of the solar system as the sun and Jupiter plus a few billion insignificant pieces of smaller junk sharing a common orbit around the galactic center. What made them a "solar system" was that they were close enough together to be gravitationally bound, so they appeared to local observers to be orbiting each other.
Those who do study history are doomed to stand helplessly by while everyone else repeats it.