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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 and stage an emergency scenerio drill, just to prepare for the day when there is an armageddon-destined asteriod?
Belief? Hope? Preference?The Existential Vortex
Does this mean my Pontiac is going to go on another killing spree?
I swear to God...I swear to God! That is NOT how you treat your human!
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?
Obviously we did already because there's a camera shot from the asteroid of Earth.
Obviously we did already because there's a camera shot from the asteroid of Earth.
That's not a photograph, it's a crappy 3D render.
http://www.universetoday.com/wp-content/uploads/2009/01/earth_toutatis_big.gif
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?
Apparently I was not-so-obviously joking.
I think that the fill-in /. reply here is "WHOOSH".
It is dangerous to be right when the government is wrong.
since the asteroid is coorbital, it's a little misleading to say that it's "passing" within 400,000 miles. what's really interesting is that it will be at more or less that same distance for many months, suggesting that it and earth share a common history.
according to this java simulation of the object's orbit, it won't be this close again until about 2100.
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.
Space is a big place. Think of it more as if I-80, that great American cross-country interstate, wrapped around the world instead of just our little country. Even with one lane, you might never see another car. To add to that, think of I-80 as being a mile wide. The chances of hitting another car go down by a bit then, even if you happen to overtake the other car.
Whenever I hear of something like this, I have to wonder if it is a "lost" interplanetary probe (or the upper stage of one, or some other related debris). With this orbit, 2009 BD could be an old lunar flyby, maybe from the 1960's.
Remember, the size estimate requires an albedo estimate, and rocket pieces tend to be very reflective, and thus will appear to be larger if the albedo is set too low, so if it was a spacecraft it would not be 10 meters, but maybe 4 or 5 at most. The Apollo 8, 10 and 11 third stages would be a possible candidate. (After Apollo 11, the third stages were impacted on the Moon to serve as sources for the seismometers.)
Such lost probes will return to near the Earth, but perturbations will tend to move them slowly further away with time.
3753 Cruithne is in a Earth resonance orbit and is the first asteroid called "Earth's second moon". I don't know how many we are supposed to have now, but with this one, it is at least 3.
Well 640 000 km is, in cosmic terms, the same lane : it's only a little further out than the moon (at 400 000 km).
Think of the Earth/Moon as a car and the asteroid as a moped lane-splitting.
*Landing an object on an asteroid is neither cheap nor convenient...even a robotic device is difficult. *
Yes, but it has already been done:
http://en.wikipedia.org/wiki/Hayabusa
In fact, Hayabusa wasn't supposed to actually land, but it did, for about 30 minutes. It may have a sample of the asteroid that it is bringing back in 2010, just in time for a re-issue of the Late Michael Crichton's Andromeda Strain.
The asteroid was not destroyed by the landing....just like the comet that was hit by a space probe did not disintegrate either:
http://www.space.com/missionlaunches/050704_deepimpact_success.html
"Next to impossible": I do not think this means what you think it means.
Most asteroids are most likely actually just big piles of smaller material. They have very little structural integrity. If you tried to apply a force to one 'spot' on the asteroid the results would be at best unpredictable. Material would shift around, you might even just sort of push through it.
Another related problem is that you need to push against the asteroid THROUGH its center of mass. If that center of mass is not fixed, then you can't really do that.
Beyond that, even if the asteroid is a solid chunk of rock, you still have to despin it before you can push it, thus the whole operation becomes a lot harder, plus if it IS a rubble pile, then you may not even be able to despin it or it would be pretty hard to do so.
A gravity tractor on the other hand suffers none of these disadvantages. All parts of the asteroid are going to be attracted to the tractor. It may STILL be somewhat complicated, but probably less so. In any event we won't really know until we try.
Finally, what difference does it really make how fast you accelerate the asteroid? The point would be to put it on the desired course. Doesn't really matter if the mission is 1 hour long or 10 years as long as you get the results you want.
"Malo periculosam, libertatem quam quietam servitutem." -- Jefferson
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.
The total delta v required to get from Earth to Mars is somewhat under 5 km/s. In order to impart that kind of velocity to an asteroid you would need something like 10 huge nuclear rockets or something (and a small asteroid).
This is why it is important to detect these things well in advance. The delta v required to deflect something that is a year from crashing into Earth is going to be on the order of half the diameter of the Earth in a year. In other words VERY low. A year is really close. Realistically a few mm/s really IS all you need. That's the beauty of it all. If you can arrange it so that you're course correction is initiated at a favorable point in the asteroid's orbit, then the energy required is pretty trivial.
If you're talking about doing it very close, then we're WAY beyond any rocket technology we've even thought about inventing. The highest velocities ever achieved via direct power (not gravity assist) are on the order of 7 km/s and that is for a space probe massing a few 100 kilos. A 10 meter diameter asteroid masses on the order of millions of kilos. Practically speaking even with a gravity tractor and a required delta v in the mm/s range we aren't even close yet to deploying a system with the required capabilities.
And how many 1000's of tons would a 'net' of some sort weigh? On top of the reaction mass and engines, etc. Hard to say what will make sense at some point in the future, but gravity tractors at least would be simple and are far closer to being possible than anything else I've ever heard suggested.
"Malo periculosam, libertatem quam quietam servitutem." -- Jefferson
Seriously, though, it intuitively seems like the danger from rogue asteroids comes from an intersecting orbit, with a high closure velocity prior to impact. This one may cause problems if it enters our atmosphere, but if it's already in a similar orbit, the energy dissipated would be mainly that associated with falling into our gravity well. How much energy is needed to cause Armageddon in this manner? (As distinct from the LHC manner of Armageddon, which seems more efficient, in theory...)
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