Small Asteroid Making 400,000 Mile Pass By Earth 157
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)."
Re: someone did (Score:3, Interesting)
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 [universetoday.com]
Re:Let's land on it. (Score:2, Interesting)
Somewhat more likely, apparently, we may send an aircraft [wikipedia.org] to travel near the asteroid and try to use its small but constant gravitational pull to modify its course.
A lost Lunar Probe ? (Score:5, Interesting)
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.
Re:Mining NEOs? (Score:3, Interesting)
Re:How many "second moons" do we have ? (Score:2, Interesting)
Re:Mining NEOs? (Score:3, Interesting)
Are NEOs abundant enough to do that? How many NEOs are even candidates for mining?
Well, to start close to home, there are a few thousand of them orbiting the Earth. There are lots of dead satellites out there, and most are stuffed full of electronics gadgetry. Granted, the chips might not be worth salvaging. But you can always use resistors and capacitors, and there's gotta be a few thousand km of wires that could be collected and added to the parts closets in your orbiting labs. This should be a lot cheaper than manufacturing replacements and lifting them from Earth. It would also help with the slowly growing problem of dodging all that orbiting shrapnel, before we end up with visible Saturn-like rings around our planet.
Also, if we can develop a reasonably cheap way to intercept incoming NEOs, over time we would clear out most of the population that intercepts our orbit, slowly making life on Earth more secure.
And eventually we're going to find it useful to be able to get our minerals delivered in space without the expense of lifting them up from Earth.
The planet has a good enough population of impact craters of all sizes, that we should take seriously any ideas for collecting the NEOs and putting them to better use.
But the best argument for going after a 10m object is that it would be a good start in learning to handle the 100m and 1000m objects that are also out there somewhere, heading our way.
Re:Earth a Dwarf Planet? ;-) (Score:2, Interesting)
I don't mind the "promotion" of Ceres to the status of a planet. I think that is a long time coming.
Of course, I personally think that physical characteristics such as having hydrostatic equilibrium and perhaps a measurable atmosphere ought to be criteria for a planet instead of solar centric definitions.
If this means Mercury is "demoted" to dwarf planet status and Titan is "promoted" to the status of a full-fledged planet (thus having the Earth's Moon as a dwarf planet too) is also fine with me. These are all bodies of the solar system that are quite interesting in their own right, and having a couple dozen planets instead of the familiar nine would be a good thing.
Besides, a consistent metric for what is a "planet" would help for extra-solar planets, including planets in stellar systems that are still at early stages of development for things that haven't "cleared out their orbits" yet due to a lack of time.
Re:Mining NEOs? (Score:3, Interesting)
5 km/s!!! hehe (Score:3, Interesting)
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.
Re:summary misses the interesting point of coorbit (Score:3, Interesting)
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...)