Objects in Space

February 21, 2009 1:44 AM

Do gravity holes harbour planetary assassins?
posted by Artw (23 comments total)

"If we see a big asteroid there, it might be worth taking it out pre-emptively," says Gott, "and by that I mean blowing it to pieces."

Radioactive debris seems like one of the less interesting things we might park in L4 or L5 (assuming they're not filled with crap already).
posted by ryanrs at 2:47 AM on February 21, 2009

Do gravity holes harbour planetary assassins?

Like the death star?

That'd be a no from me.
posted by multivalent at 2:52 AM on February 21, 2009

Christ, what an assassin hole.
posted by weapons-grade pandemonium at 7:43 AM on February 21, 2009 [2 favorites]

Hey, so that's where all the TARP money went! (first shoe hits the stage)

Woah, so that's where my luggage is! (second shoe flies past the drummer)

Well, whatever's up there can't be worse than my mother-in-law visiting us! (concussion)
posted by Lipstick Thespian at 8:02 AM on February 21, 2009 [2 favorites]

Does New Scientist harbor responsible writing?

no.
posted by 7segment at 8:02 AM on February 21, 2009 [6 favorites]

Does "Finding Jupiter's L4 point" give it pleasure?
posted by woodway at 8:05 AM on February 21, 2009 [2 favorites]

"Some have even speculated that alien spacecraft are watching us from the Lagrangian points, looking for signs of intelligence."

I'd think they be getting pretty certain of the results of that by now.
posted by sfts2 at 8:08 AM on February 21, 2009

Gravity hole seems like a horrible misnomer, but I don't want to be the pedant who complicates the explanation.
posted by BrotherCaine at 8:13 AM on February 21, 2009

Off-topic, but reading this was slightly odd - I know two of the astronomers mentioned in the article.
posted by AppleSeed at 8:20 AM on February 21, 2009

Shame on science reporting that thinks science is only fun if it involves alien intelligence and blowing shit up.

The Wikipedia article on Lagrangian points is surprisingly good, particularly the diagram.
posted by Nelson at 8:29 AM on February 21, 2009 [1 favorite]

I was hoping this was going to be a link to one of those single-serving sites, where the whole page is the word "No" in big letters.

Also "Gravity canceling out so it is truly weightless" is also wrong. If that were accurate, things there wouldn't orbit the sun, they'd fly off in whatever direction they were going! The Lagrange points are just other places in or around a planet's orbit where other stuff can orbit in lock-step with earth too. L4 and L5 are actually stable, like a marble in a valley. L1, L2, & L3 are unstable, like a marble balanced on the top of a hill. So L4 & L5 is where the space-marbles will tend to accumulate.

I think a powered spacecraft could stay at L1, L2, or L3 with minimal energy expeditures.
posted by aubilenon at 8:33 AM on February 21, 2009 [2 favorites]

I think I need much, much more talk about space-marbles from Aubilenon.

*runs off to get listening mat and juice box*
posted by Lipstick Thespian at 9:06 AM on February 21, 2009 [1 favorite]

aubilenon: as the article points out, the L1 and L2 points already are used for spacecraft: among others SOHO is at L1 and WMAP is at L2. L3, IIRC, is particularly unstable.
posted by Electric Dragon at 9:12 AM on February 21, 2009

Earth/Luna Lagrange points L4 and L5 are often used in science fiction stories as places to park space colonies. The Wikipedia article mentions that things orbit along the lines of the equipotential surfaces. Doesn't this imply 3D surfaces that extend above and below the orbital plane?


Metafilter : where the space-marbles will tend to accumulate.
posted by Enron Hubbard at 9:15 AM on February 21, 2009

Everyone knows that Gor is at L3.
posted by nax at 9:26 AM on February 21, 2009

Does "Finding Jupiter's L4 point" give it pleasure?

Only if your probe has a dolphin or rabbit sticking out the side with ears at the right angle.
posted by fatbird at 10:07 AM on February 21, 2009

L1, L2, & L3 are unstable, like a marble balanced on the top of a hill.

This is how I thought of them too, until Nelson's excellent diagram showed me they are actually saddlepoints, and therefore unstable like a marble on the lowest point on a ridge between two hills.
posted by jamjam at 12:51 PM on February 21, 2009

What a bizarre, over-the-top, article.
posted by delmoi at 5:29 PM on February 21, 2009

"If we see a big asteroid there, it might be worth taking it out pre-emptively," says Gott, "and by that I mean blowing it to pieces."

wouldn't these pieces be more likely to hit the earth, then? - and some of those pieces would not be insignificant
posted by pyramid termite at 8:19 PM on February 21, 2009

Everyone knows that Gor is at L3.

Be that as it may, the GoreSat is destined for L₁.

I don't know where Al is right now.
posted by dhartung at 8:46 PM on February 21, 2009

Well, sure, if by "gravity hole" you mean "black hole," & by "planetary assassin," you mean "Darkseid."

I thought you of all people would already know this, Artw.
posted by Pronoiac at 11:00 PM on February 21, 2009 [1 favorite]

"wouldn't these pieces be more likely to hit the earth, then? - and some of those pieces would not be insignificant"

Possibly. But it's a lot better to be hit by several smaller pieces than one big piece. Ideally we'd just monitor the dangerous pieces and then launch a blow'em up mission IFF one starts deviating towards us.
posted by Mitheral at 8:21 AM on February 22, 2009

I think that this article was planted by the Yellowstone supervolcano as a diversion. Eternal vigilance &c.
posted by Halloween Jack at 8:33 AM on February 23, 2009 [1 favorite]