Beta
×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Small Asteroid Making 400,000 Mile Pass By Earth

CmdrTaco posted more than 5 years ago | from the summon-bruce-willis dept.

Space 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)."

cancel ×

157 comments

Sorry! There are no comments related to the filter you selected.

Let's land on it. (5, Funny)

FredFredrickson (1177871) | more than 5 years ago | (#26607431)

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?

Re:Let's land on it. (4, Funny)

oldspewey (1303305) | more than 5 years ago | (#26607461)

And soon ... those actors aren't getting any younger you know.

Re:Let's land on it. (3, Insightful)

telchine (719345) | more than 5 years ago | (#26607473)

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?

Re:Let's land on it. (4, Funny)

onion2k (203094) | more than 5 years ago | (#26607525)

How do you propose to land on a 10 meter wide asteroid?

Very carefully. :)

Re:Let's land on it. (5, Funny)

Tybalt_Capulet (1400481) | more than 5 years ago | (#26608163)

Easy, I used to land on womp rats back hope with my t-16, and they're no wider than 10m.

Re:Let's land on it. (5, Funny)

mea37 (1201159) | more than 5 years ago | (#26607533)

With an asteroid that small, it would be debatable whether the ship landed on it, or the other way around...

So I guess you'd have to use a soyuz.

(Get it? Because in soviet russia... Never mind.)

Re:Let's land on it. (3, Funny)

dkleinsc (563838) | more than 5 years ago | (#26607929)

In other words: "We didn't land on the space rock. The space rock landed on us."

(with apologies to Malcolm X)

Re:Let's land on it. (0, Redundant)

Aqua_boy17 (962670) | more than 5 years ago | (#26608009)

In Soviet Russia, asteroid lands on you?

Re:Let's land on it. (0)

Anonymous Coward | more than 5 years ago | (#26609649)

In Soviet Russia, asteroid lands on you?

Better than them landing where I live (not Russia)

Re:Let's land on it. (0, Redundant)

gblackwo (1087063) | more than 5 years ago | (#26609959)

I think you guys might be missing the parents REAL joke. In order to land ON the asteroid the following is taken into consideration.

Since he is proposing the ship being larger, the asteroid would actually be landing on the ship.

If you allow the asteroid to land on the soyuz, -- in soviet russian soyuz lands on asteroid.

Thus, the only way to land ON the asteroid is with a russian ship and a bad joke. Get it?

Re:Let's land on it. (1)

Linuss (1305295) | more than 5 years ago | (#26608085)

Land on my ship, asteroid?

Nah, doesn't have as nice a ring to it...

Re:Let's land on it. (1)

balbord (447248) | more than 5 years ago | (#26608569)

I propose one of these [slashdot.org] !

Re:Let's land on it. (1)

tangent3 (449222) | more than 5 years ago | (#26609753)

I used to bullseye womp rats in my T-16 back home. They're not much bigger than two meters.

Re:Let's land on it. (0)

w0mprat (1317953) | more than 5 years ago | (#26610415)

Hey I resent that. I lost my family that way.

Re:Let's land on it. (1)

Locklin (1074657) | more than 5 years ago | (#26610253)

Cut in a few pieces, it might just fit in the cargo fuselage of the Space Shuttle.

Of course, it would be far too much mass to land, and it's way, way outside the Shuttle's range, but it makes the idea of "landing" more like "docking" or "recovering."

Re:Let's land on it. (1)

drpimp (900837) | more than 5 years ago | (#26610477)

With nanobots DUH!

Re:Let's land on it. (1)

cashman73 (855518) | more than 5 years ago | (#26607483)

At least they can reuse those clips of Morgan Freeman standing in for Barack Obama telling us we're all going to die,...

Re:Let's land on it. (1)

Zaatxe (939368) | more than 5 years ago | (#26607573)

No, you are not. And I for one welcome our asteroid drilling overlords!

Re: someone did (4, Funny)

hammarlund (568027) | more than 5 years ago | (#26607591)

Obviously we did already because there's a camera shot from the asteroid of Earth.

Re: someone did (2, Interesting)

A. B3ttik (1344591) | more than 5 years ago | (#26607655)

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: someone did (1)

hammarlund (568027) | more than 5 years ago | (#26607691)

Apparently I was not-so-obviously joking.

Re: someone did (2, Funny)

dotancohen (1015143) | more than 5 years ago | (#26607735)

Apparently I was not-so-obviously joking.

I think that the fill-in /. reply here is "WHOOSH".

ob... (1)

dotancohen (1015143) | more than 5 years ago | (#26607749)

That's not a photograph, it's a crappy 3D render.

That's no moon....

(fuck you saw that coming didnt you?)

Re:Let's land on it. (1)

Thiez (1281866) | more than 5 years ago | (#26607605)

Why would we do something tricky like 'land on it' when we can send a nuke to 'collide with it' instead?

Re:Let's land on it. (1)

Hognoxious (631665) | more than 5 years ago | (#26608775)

Does it have any oil?

Re:Let's land on it. (1)

pbhj (607776) | more than 5 years ago | (#26609457)

Yeah, nuking it from orbit is the only way to be sure ... [wish I new what that meme referred to]

Re:Let's land on it. (1)

Captain Hook (923766) | more than 5 years ago | (#26609629)

Just in case you are actually being serious, although I find that hard to believe http://www.imdb.com/title/tt0090605/quotes [imdb.com]

Re:Let's land on it. (2, Informative)

pbhj (607776) | more than 5 years ago | (#26610245)

Suddenly my whole life makes sense. Thanks.

Re:Let's land on it. (1)

bonehead (6382) | more than 5 years ago | (#26609729)

The movie Aliens.

Re:Let's land on it. (1)

hierophanta (1345511) | more than 5 years ago | (#26607737)

I agree land on it! (unmanned mission) Attach a small transceiver sending data back to earth -- we dont need our own spaceships we could just hitch a ride on the '2009 BD express'

no really couldnt we?

Re:Let's land on it. (1)

Keeper Of Keys (928206) | more than 5 years ago | (#26607801)

Nice idea, but let's try it on an asteroid that's heading somewhere interesting, rather than one that's in the same orbit as the Earth.

Re:Let's land on it. (1)

hierophanta (1345511) | more than 5 years ago | (#26608489)

from the article. So far, little is known about the new 10 meter asteroid in our near-Earth neighbourhood, but it provides us with an exciting opportunity to track its laborious orbit to see whether it will eventually be ejected after making a close pass to the Earth's gravitational field (as was the case with 2003 YN107 in 2006).

while i must admit i did not read that before i wrote my OP. i do still think it would be valuable to stick some sensors on it.

Re:Let's land on it. (2, Interesting)

Schiphol (1168667) | more than 5 years ago | (#26607821)

Why do you people assume that drilling is our best shot against an asteroid? Despite Armaggedon, it is not.

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.

Re:Let's land on it. (4, Funny)

corbettw (214229) | more than 5 years ago | (#26608325)

Somewhat more likely, apparently, we may send an aircraft to travel near the asteroid

If you have to wait for an aircraft to do the job, I think it's probably too late.

Re:Let's land on it. (1)

R2.0 (532027) | more than 5 years ago | (#26609307)

Yes, I remember reading that plan here on Slashdot - it was remarkable in that it seemed to wholly ignore the law of gravity.

Besides, if we really can direct the trajectory of space objects, I'd suggest dropping them on Congress.

Re:Let's land on it. (1)

camperdave (969942) | more than 5 years ago | (#26609543)

Although the idea of using a spacecraft's gravity to tug an asteroid off course may work, I think it would be far, far easier to land the spacecraft on the asteroid "nose first" and push the asteroid. You could impart a delta v of a few millimeters per second to an asteroid in a matter of seconds rather than years.

There are good reasons (4, Informative)

Giant Electronic Bra (1229876) | more than 5 years ago | (#26609907)

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.

Re:Let's land on it. (0)

Anonymous Coward | more than 5 years ago | (#26610089)

It's a Freudian thing. We all want our drills to be the one to pierce the heavens, I guess.

Re:Let's land on it. (2, Funny)

PolygamousRanchKid (1290638) | more than 5 years ago | (#26608861)

Am I the only one who thinks we should attempt to land on it and stage an emergency scenerio drill

I was thinking that we could land on it, set up tax havens, gambling casinos, brothels and Ponzi schemes.

Think of it as a bubbling-broth mix of Las Vegas, Wall Street and the Cayman Islands.

Now a fun place like that would finally put our galaxy on the interstellar map.

not as rare (-1, Offtopic)

Anonymous Coward | more than 5 years ago | (#26607433)

as a first toast!

Not again! (3, Funny)

GodfatherofSoul (174979) | more than 5 years ago | (#26607459)

Does this mean my Pontiac is going to go on another killing spree?

Re:Not again! (1)

jrmcc (703725) | more than 5 years ago | (#26607661)

Accompanied by AC/DC?

Even worse... (1)

wiredog (43288) | more than 5 years ago | (#26607899)

Another AC\DC revival.

Mining NEOs? (5, Insightful)

A. B3ttik (1344591) | more than 5 years ago | (#26607487)

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?

Re:Mining NEOs? (-1, Troll)

Anonymous Coward | more than 5 years ago | (#26607607)

OIIIIIIL they got OIIIIIL!!! Send the Marines now! Let's bomb those NEOs to stoneage!
Ops. I forgot that Dubbya left the White House...

Re:Mining NEOs? (1)

Dripdry (1062282) | more than 5 years ago | (#26607621)

We could crawl before we walk. Once the kinks and difficulties are worked out it would be easier (and probably cheaper) to begin mining more profitable objects.

Re:Mining NEOs? (1)

A. B3ttik (1344591) | more than 5 years ago | (#26607715)

Yeah, I agree it would be a good training exercise to land on them and maybe even work on mining techniques. But the article specifically states "tap their resources."

Maybe they foresee some future orbital spaceyard where its easier and cheaper to get metal from already orbiting NEOs than it is to send up materials from Earth?

Re:Mining NEOs? (1)

Dripdry (1062282) | more than 5 years ago | (#26607837)

Hm. That seems to make sense. Are NEOs abundant enough to do that? How many NEOs are even candidates for mining?

Re:Mining NEOs? (0, Offtopic)

2names (531755) | more than 5 years ago | (#26608449)

Are NEOs abundant enough to do that?

I thought there could be only ONE NEO. Wait...that's Highlander, not the Matrix.

Dammit. I hate it when I get ridiculous movie plots confused.

Re:Mining NEOs? (2, Interesting)

jc42 (318812) | more than 5 years ago | (#26609643)

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:Mining NEOs? (1)

Sibko (1036168) | more than 5 years ago | (#26607651)

Carve out the inside, insert space station. Voila.

Besides that though, is there even a way to get these minerals down to the Earth reliably and cheaply? I imagine there are reasons large re-entry vehicles carrying hundreds of tons worth of ore would not work.

Re:Mining NEOs? (1)

berend botje (1401731) | more than 5 years ago | (#26607765)

Just use parachutes. Large ones.

Continent sized parachutes, think about it!

Re:Mining NEOs? (0)

Anonymous Coward | more than 5 years ago | (#26607695)

Kryptonite, of course. That's needed in case Evil-Superman shows up again! Man, have you no forsight at all? I'm glad my security does not lie in your hands!

Re:Mining NEOs? (1)

ijakings (982830) | more than 5 years ago | (#26607717)

They clearly contain "Bullet-Timeium"

Depends on the NEO composition (1, Insightful)

Anonymous Coward | more than 5 years ago | (#26607781)

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.

Re:Mining NEOs? (3, Insightful)

Vellmont (569020) | more than 5 years ago | (#26607817)


Or do these NEOs have some kind of exotic resource that I am unaware of?

The "exotic" resource would most likely be "every day minerals not stuck in earths gravity well".

It's expensive in terms of energy to lift things into orbit. This stuff is already free of earth's gravity. It _might_ be advantageous someday to mine this stuff if we wanted to make things in orbit.

Re:Mining NEOs? (2, Interesting)

ianare (1132971) | more than 5 years ago | (#26608441)

... Especially since metals behave differently in microgravity [findarticles.com] , possibly leading to new alloys [aist.go.jp] and manufacturing processes not possible or practical on Earth.

Re:Mining NEOs? (1)

Lost Race (681080) | more than 5 years ago | (#26610225)

It's also good near-Earth practice for eventual asteroid belt mining operations.

Re:Mining NEOs? (1)

cpu_fusion (705735) | more than 5 years ago | (#26608181)

Or do these NEOs have some kind of exotic resource that I am unaware of?

Matrixium -- it used to be worth quite a bit, but it has been overmined.

Re:Mining NEOs? (1)

digitig (1056110) | more than 5 years ago | (#26608317)

Or do these NEOs have some kind of exotic resource that I am unaware of?

Might be worth checking for naturally occurring 2(5)6 dilithium 2(:)l diallosilicate 1:9:1 heptoferranide.

Re:Mining NEOs? (1)

nomorecwrd (1193329) | more than 5 years ago | (#26609695)

AKA: Dilithium crystals.
nice!

Re:Mining NEOs? (2, Informative)

mbone (558574) | more than 5 years ago | (#26608455)

There are plenty of larger NEOs that are energetically easy to get to. In fact, there are quite a number that the Apollo spacecraft could have reached and returned from, and there were plans to do this in the late 1960's (using the Saturn V 3rd stage as living quarters in route, and replacing the LEM with provisions), but neither LBJ nor Nixon was really interested in manned exploration beyond the Moon. I have a feeling that JFK would have gone for this, though, as well as for the manned Venus orbiter plans using the same technology.

Obligatory reference (0, Redundant)

jtseng (4054) | more than 5 years ago | (#26607513)

"That's no moon..."

No tractor beam yet... (1)

GerardAtJob (1245980) | more than 5 years ago | (#26607527)

... I'm back to Privateer ... Per

Asteroid mining? (1)

Dripdry (1062282) | more than 5 years ago | (#26607557)

So is something like this a top candidate for learning/testing asteroid mining, or are there other types of objects that are more convenient?

Re:Asteroid mining? (1)

furby076 (1461805) | more than 5 years ago | (#26607877)

Landing an object on an asteroid is neither cheap nor convenient...even a robotic device is difficult. First to hit it is difficult - its a fast moving object - and we will likely have one shot. Second to land on it and not destroy what is landing on it would be nearly impossible. Third to "mine" valuable information from the asteroid is difficult, and may turn up nothing more then ice (the good stuff may be deep inside and outside the range of a small automated vehicle) and forth getting that information sent back to Earth is pain since we have no control which way this object will face.

With current technologies it is next to impossible. We first need to develop tools that can overcome the basic hurdles (getting there safely) then make those tools able to provide us with useful information (otherwise what's the point)?

Re:Asteroid mining? (2, Informative)

NXIL (860839) | more than 5 years ago | (#26608605)

*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 [wikipedia.org]

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 [space.com]

"Next to impossible": I do not think this means what you think it means.

Re:Asteroid mining? (1)

Iowan41 (1139959) | more than 5 years ago | (#26608687)

Nonsense, we've done it before, and at this size it would actually be more like the Gemini 6 and 7 mission. Are we sure this isn't an Apollo 2nd stage booster? We've been fooled by that once before. Too bad we aren't ready for this, it could be a nice place to put a radio telescope for -really- long baseline interferometry. What class asteroid is it? If nickel iron, eventually we could heat it up and blow it up into a small habitat. If icy or chondritic, it wouldn't take very much delta- (relatively speaking) to land it on the moon.

Only /. Headlines Truly Scare Me (-1)

Anonymous Coward | more than 5 years ago | (#26607569)

One of these days...

"Previously Unknown Large Asteroid on intercept path with Earth"

or

"Early reports are that the area 700 miles wide by 83 miles deep that's on fire on CNN is believed to have been destroyed as the planet rotated through a micro black hole believed to have been formed after this week's LHC test."

How many second moons do we have? (1)

itsybitsy (149808) | more than 5 years ago | (#26607697)

Ok, this is the third second moon?

They say there is nothing to worry about but it's just 640,000 KM away which is just outside the orbit of the moon at 400,000 km... yikes... a three body problem... not predictable...

Planet X Discovered!

Vulcan Discovered!

Kinda deflating... kinda cool anyways.

I know we can mount a camera on it pointed at the earth so we can see ourselves. EarthCamOne.

Re:How many second moons do we have? (0)

Anonymous Coward | more than 5 years ago | (#26608045)

Zero.

Co-orbital asteroid != moon.
And also kelvinmega != kilometer.

Re:How many second moons do we have? (1)

itsybitsy (149808) | more than 5 years ago | (#26609267)

Geeze you're a nit picker... it wasn't I who said we had new moons, it was the silly folks writing the article... I'm just playing with that... geeze...

You're right KM != km... oops... a typo... again a nit picker who adds nothing...

Say something funny!

Re:How many second moons do we have? (1)

Teancum (67324) | more than 5 years ago | (#26609825)

Do man-made objects count?

The ISS is certainly much larger than this "asteroid", and it seems to have several interesting qualities about it. The ISS is also going to be "permanently" in space as nobody wants to see that thing come crashing back down to the Earth... ever.

The U.S. Department of Defense currently is tracking about 13,000 different items in orbit around the Earth. All of them are substantial enough to warrant concern if they pass near operational spacecraft.

So does this make moon #13001?

BTW, there is reason to believe that even this "asteroid" may be man-made, and merely something that achieved Earth escape velocity and is now merely orbiting the Sun instead, like the Apollo 12 3rd stage engine of the Saturn V [wikipedia.org] . Not all of the objects that went into solar orbit have been tracked, so perhaps this is one coming back home?

Earth a Dwarf Planet? ;-) (3, Insightful)

macxcool (1370409) | more than 5 years ago | (#26607725)

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?

Re:Earth a Dwarf Planet? ;-) (1)

harperska (1376103) | more than 5 years ago | (#26608039)

I suppose then by that interpretation of the IAU definition, Jupiter [wikipedia.org] is a dwarf planet. IMHO, the whole dwarf planet classification is just silly, and completely meaningless.

Re:Earth a Dwarf Planet? ;-) (2, Interesting)

Teancum (67324) | more than 5 years ago | (#26610051)

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.

earth not a planet? (0)

Anonymous Coward | more than 5 years ago | (#26607729)

if the astroid is co-orbital, then the
earth is not a planet. thanks tyson!
your zeal to demote pluto seems a bit
off axis.
wiki def [wikipedia.org]

zomg! (0)

Anonymous Coward | more than 5 years ago | (#26607791)

omg, we'all gonna DIIIIEEE!!

uh.... no, wait...

Okay, maybe I'm missing something here... (1, Insightful)

killmenow (184444) | more than 5 years ago | (#26607811)

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.

Re:Okay, maybe I'm missing something here... (4, Insightful)

lymond01 (314120) | more than 5 years ago | (#26608065)

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.

Re:Okay, maybe I'm missing something here... (1)

mbone (558574) | more than 5 years ago | (#26608371)

This is just sloppy terminology.

They are in close, but not identical, orbits around the Sun.

Re:Okay, maybe I'm missing something here... (2, Informative)

ianare (1132971) | more than 5 years ago | (#26608591)

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.

summary misses the interesting point of coorbital (4, Informative)

cathector (972646) | more than 5 years ago | (#26607879)

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 [nasa.gov] , it won't be this close again until about 2100.

Re:summary misses the interesting point of coorbit (1)

karlwilson (1124799) | more than 5 years ago | (#26609555)

suggesting that it and earth share a common history.

Or just a coincidence, however unlikely that may be. With all of the asteroids wandering through space, it was bound to happen at some point. Reminds me of the thought I have every now and then about a photons journey from the sun all the way to your retina, and how many refractions and reflections that one photon has been through to end up in your eye.

Re:summary misses the interesting point of coorbit (1)

cathector (972646) | more than 5 years ago | (#26609731)

true, it could be coincidental - earth may have captured it or it could be a total fluke, but looking at the simulation of the orbits, it sure *looks* like they were once one body.

probably it's a lost mesozoic space capsule.

A lost Lunar Probe ? (4, Interesting)

mbone (558574) | more than 5 years ago | (#26608109)

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.

How many "second moons" do we have ? (3, Informative)

mbone (558574) | more than 5 years ago | (#26608137)

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.

Re:How many "second moons" do we have ? (1)

ianare (1132971) | more than 5 years ago | (#26608697)

Isn't a moon defined basically as a natural satellite ? If the body revolves around the Sun why would it be called an Earth moon ? Not being rhetorical, just curious.

Re:How many "second moons" do we have ? (2, Insightful)

mbone (558574) | more than 5 years ago | (#26608935)

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.

Re:How many "second moons" do we have ? (2, Interesting)

TheForgotton (995762) | more than 5 years ago | (#26608747)

I'm in the midst of reading Stephen Baxter's novel Manifold Time, and it seems to be about an NEO mining expedition to Cruithne. Cool timing on this article.

Co-orbital? (1)

HardCase (14757) | more than 5 years ago | (#26609115)

If it shares the Earth's orbit, shouldn't its speed, relative to the Earth, be zero? Objects in the same orbit travel at the same speed, don't they? Am I just being pedantic?

Re:Co-orbital? (1)

NivekEnterprises (309259) | more than 5 years ago | (#26609325)

Not if their masses are different. Different masses require different speeds to keep the same orbit.

Re:Co-orbital? (1)

mbone (558574) | more than 5 years ago | (#26609511)

Different masses require different speeds to keep the same orbit.

Uh, no they don't - that would be a violation of the Strong Equivalence Principal (SEP), which holds exactly in General Relativity, and has been tested via the Nordtvedt effect in Lunar Laser Ranging to better than a part per thousand.

These co-orbitals do indeed have very low speeds relative to Earth. They are not in the same orbit, just very close ones.

Re:Co-orbital? (1)

NivekEnterprises (309259) | more than 5 years ago | (#26609827)

You are quite right, I was thinking something completely different.

v=SQRT(GM/r)

So for a given radius the velocity would be the same.

Thanks for catching it.

Re:Co-orbital? (1)

artson (728234) | more than 5 years ago | (#26610029)

If it is in exactly, precisely the same orbit, then yes, the speed should be about the same, otherwise there will be a collision and one or both of the objects cease to exist, or else the larger object gravitationally captures the smaller object as a moon. I am NOT an astronomer.

Re:Co-orbital? (3, Insightful)

jc42 (318812) | more than 5 years ago | (#26610121)

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.

Re:Co-orbital? (1)

samkass (174571) | more than 5 years ago | (#26610263)

Well, firstly if it's going to pass "within X miles" of the Earth, then it's not in the same orbit, it's in one that's X miles different from the Earth. Secondly, the Earth has gravity (as do Mars and Venus) and will perturb the orbits enough to give them relative motion.

But yeah, if it's in an orbit around the sun that's almost the same as the Earth, the delta-V is going to be very low.

Re:Co-orbital? (0)

Anonymous Coward | more than 5 years ago | (#26610491)

It's complicated. If it weren't for the Earth, 3753 Cruithne would be in a solar orbit slightly larger or smaller than Earth's.

Recall that smaller orbit means shorter "year" and higher speed, larger orbit means longer "year" and lower speed.

When Cruithne "catches up" to Earth, it gets gravity boosted into it's larger orbit. At which point it starts to "fall behind", since it's now in an orbit with a longer period than Earth's. When Earth "catches up" to it, Cruithne is pulled into it's smaller orbit, and then "pulls away" since it's now going faster than the Earth is. Repeat. That is one form of "co-orbital".

Here's an idea... (0)

Anonymous Coward | more than 5 years ago | (#26609441)

I think we should go out there, grab it, and bring it back here. It'd make a great museum piece.

Damit (1)

w0mprat (1317953) | more than 5 years ago | (#26610399)

While I'm pleased they have found my spaceship and not recognised what it is, it appears to have slipped out of parking orbit.
Load More Comments
Slashdot Login

Need an Account?

Forgot your password?

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>