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Pulsar Gets the Munchies, Snacks On an Asteroid

Soulskill posted about 7 months ago | from the om-nom-nom dept.

Space 54

astroengine writes "In research accepted for publication in the Astrophysical Journal, astronomers documented the anomalous spin rate of a pulsar that has been observed 'multiple times' between 1988 and 2012. In September 2005, the spin rate of the well-observed PSR J0738-4042 changed and a team of astronomers headed by Paul Brook, of the University of Oxford, think they know why. 'The data lead us to postulate that we are witnessing an encounter with an asteroid or in-falling debris from a disk,' they write in a paper published to the arXiv pre-print service. The moral of the story? It's not just black holes that get the asteroid munchies."

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54 comments

munchies (-1, Offtopic)

Anonymous Coward | about 7 months ago | (#45681923)

I get the munchies for these all the time [youtube.com]

Pulsars need to eat, too (0)

ackthpt (218170) | about 7 months ago | (#45682079)

But when the get gas, it's gamma rays, phew, light a match!

Re:Pulsars need to eat, too (1)

Salgak1 (20136) | about 7 months ago | (#45682095)

No need, the gamma flux will light the match for you. That, and nearby planets as well. . .

Re:Pulsars need to eat, too (5, Insightful)

phrostie (121428) | about 7 months ago | (#45682271)

all jokes aside, if something as simple as debris falling into the pulsar will change it's spin rate, then maybe using these for navigation isn't so reliable after all.

just a thought.

Re:Pulsars need to eat, too (1)

cusco (717999) | about 7 months ago | (#45682509)

Any addition of mass to a pulsar will change it's spin rate, whether it be a large asteroid or an atom of water. I think the fact that we can detect the change created by something as small as an asteroid is incredibly cool. Besides, it's not the spin rate of the pulsar that would be used for navigation, it would be the object's location. The spin rate is just a convenient marker to identify the star. As long as the spin rate is within a certain margin of error they can assume they are looking at the right star.

Re:Pulsars need to eat, too (0)

Anonymous Coward | about 7 months ago | (#45682633)

Idiot. It's called "pulsar navigation" because it's using the spin rate, otherwise we could use plain stars and call it "star navigation". Time measurement allows much more precise triangulation than angular measurement.

Re:Pulsars need to eat, too (0)

Anonymous Coward | about 7 months ago | (#45682829)

For as long as pulsar navigation has been seriously considered, we've known the spin rates of pulsars change over time. Even without collisions, pulsars' spin slow down gradually. The change is pretty slow or in small jumps like this, so for the most part they are still pretty accurate. But schemes using them for navigation usually include measurements from a reference point, like on Earth, that then transmits any relative changes that have been observed to allow for corrections.

Re:Pulsars need to eat, too (1)

egcagrac0 (1410377) | about 7 months ago | (#45682865)

Time measurement allows much more precise triangulation than angular measurement.

No, our instrumentation for angular measurement is less precise than our instrumentation for time measurement.

Either method should allow for precise triangulation, within the limits of the instrumentation.

Re:Pulsars need to eat, too (0)

Anonymous Coward | about 7 months ago | (#45686181)

When you quote something and start your reply with "No,", you better make sure that what you say is the opposite of what you're quoting.

And if absolute precision doesn't matter, then I suggest you develop a commercial product to triangulate position from radio station strength. You should get half of the GPS market because it's going to be precise within the limits of the instrumentation, just like GPS.

Re:Pulsars need to eat, too (1)

egcagrac0 (1410377) | about 7 months ago | (#45689947)

As I read it, AC is saying that trigonometry works better with lengths than with angles.

I say bullshit, the math is fine, the problem is comparing the 29 cent plastic protractor with a micrometer.

I also don't object to us using micrometers instead of protractors, since we know how to build a micrometer pretty well. I do object to indicting the math and saying "measuring angles doesn't work as well!" when the problem isn't the angle, but our ability to measure it.

Let's upgrade that protractor to a sextant and see if the math works better.

Re:Pulsars need to eat, too (1)

ackthpt (218170) | about 7 months ago | (#45684531)

Any addition of mass to a pulsar will change it's spin rate, whether it be a large asteroid or an atom of water. I think the fact that we can detect the change created by something as small as an asteroid is incredibly cool. Besides, it's not the spin rate of the pulsar that would be used for navigation, it would be the object's location. The spin rate is just a convenient marker to identify the star. As long as the spin rate is within a certain margin of error they can assume they are looking at the right star.

Always remember, the pulsar you see is an emission which was sent out as long ago as is far away, with respect to the speed of light, it has likely traveled on a curved path as everything in the universe is in motion. It is by no means a fixed point.

Re:Pulsars need to eat, too (0)

Anonymous Coward | about 7 months ago | (#45682761)

I guess you could use more pulsars than you need and apply error correcting code techniques to detect pulsars that got affected and correct for them. Working out the details would make a nice thesis.

Re:Pulsars need to eat, too (0)

Anonymous Coward | about 7 months ago | (#45688271)

There are hundreds of pulsars. If one of them eats an asteroid and changes its spin rate, you can use the others to figure out how it's changed, and recalibrate. It's fine as long as they don't all glitch at once - and they're hundreds of light-years apart, so there's nothing that could make that happen.

Re:Pulsars need to eat, too (0)

Paul Fernhout (109597) | about 7 months ago | (#45688691)

"There are hundreds of pulsars. If one of them eats an asteroid and changes its spin rate, you can use the others to figure out how it's changed, and recalibrate. It's fine as long as they don't all glitch at once - and they're hundreds of light-years apart, so there's nothing that could make that happen."

Good point! Maybe the Chinese led by engineers will work that out, as opposed to the USA led by lawyers?
http://singularityhub.com/2011/05/17/eight-out-of-chinas-top-nine-government-officials-are-scientists/ [singularityhub.com]

Amazing to think I was able to watch the Chinese Chang'e-3 lunar landing live through China TV!
http://science.slashdot.org/story/13/12/14/055230/change-3-lunar-rover-landing-slated-for-1340-utc-saturday [slashdot.org]

Although a lot of that technology was engineered by US Americans decades ago...

CCTV is now talking about how US manned space flight to the moon ended in 1972... And how NASA is 1/2 of one percent of the US budget... Although now they are talking about private space exploration in the USA...

Re:Pulsars need to eat, too (0)

Anonymous Coward | about 7 months ago | (#45689619)

Good point! Maybe the Chinese led by engineers will work that out, as opposed to the USA led by lawyers?

Of course, the risk of picking random science articles to make off topic political rants, you end up with a situation like this where systems for dealing with glitches and changes in pulsars when using them for navigation have already been developed by places like NASA, ESA and even one that was featured on Slashdot recently from Australia. And there is on going work on the topic at NASA currently.

Thanks, must have missed that one (1)

Paul Fernhout (109597) | about 7 months ago | (#45694507)

http://slashdot.org/story/13/08/26/0437213/using-pulsars-as-gps-for-starships [slashdot.org]

Of course, the source article is paywalled as a form of "artificial scarcity" dreamed up by lawyers. :-) Lawyers who base their work ultimately on the public domain of public law and court proceedings, but tell everyone else not to share...

Re:Thanks, must have missed that one (0)

Anonymous Coward | about 7 months ago | (#45695289)

The article is free on arXiv [arxiv.org] like a vast number of physics and astronomy articles.

Re:Thanks, must have missed that one (1)

Paul Fernhout (109597) | about 7 months ago | (#45702631)

Thanks for the link. By the way, eight of the authors there are from China, including the first author. Four are from Australia, one from the USA.

BTW, to be fair to lawyers, it's true that some US lawyers do good things for the general benefit -- civil rights, environmental defense, open access journal articles, open government, FOSS licensing, etc.. Examples:
http://en.wikipedia.org/wiki/A_Civil_Action [wikipedia.org]
http://web.law.duke.edu/cspd/ [duke.edu]

I guess it comes down to who has the most money to pay the lawyers, and whether some lawyers are willing to make significantly less money to work in the public interest. I guess engineers can also face the same problem -- like working on some destruction-emphasizing defense projects or monopolistic systems like DRM vs. more productive ends or more sharing-oriented approaches.

Another aspect of that:
"Our One-Party Democracy"
http://www.nytimes.com/2009/09/09/opinion/09friedman.html?_r=0 [nytimes.com]
"Watching both the health care and climate/energy debates in Congress, it is hard not to draw the following conclusion: There is only one thing worse than one-party autocracy, and that is one-party democracy, which is what we have in America today.
    One-party autocracy certainly has its drawbacks. But when it is led by a reasonably enlightened group of people, as China is today, it can also have great advantages. That one party can just impose the politically difficult but critically important policies needed to move a society forward in the 21st century. It is not an accident that China is committed to overtaking us in electric cars, solar power, energy efficiency, batteries, nuclear power and wind power. China's leaders understand that in a world of exploding populations and rising emerging-market middle classes, demand for clean power and energy efficiency is going to soar. Beijing wants to make sure that it owns that industry and is ordering the policies to do that, including boosting gasoline prices, from the top down.
    Our one-party democracy is worse. The fact is, on both the energy/climate legislation and health care legislation, only the Democrats are really playing. With a few notable exceptions, the Republican Party is standing, arms folded and saying "no." Many of them just want President Obama to fail. Such a waste. Mr. Obama is not a socialist; he's a centrist. [Actually, more of a corporatist?] But if he's forced to depend entirely on his own party to pass legislation, he will be whipsawed by its different factions. ..."

The fact is, many public benefit things like FOSS or basic R&D should be funded collectively, and government should be spending money or redistributing it to account for positive and negative externalities. For example, renewables have been cheaper than fossil fuels or nuclear since the 1970s if you account for pollution, defense, and risks. But instead of paying more for gas at the pump, we pay a lot of taxes (or incur public debt) for "defense" spending in the middle east, and we have higher medical bills, and people live in fear of Fukushima-style meltdowns, etc..

Still, while I think the climate is changing, but it's not clear the best approach to that is CO2 limits. If I had to choose between CO2 limits versus a global basic income along with free mobility between nations (lawyer-y things), I'd take the latter, given that it is too late to stop lots of climate change and wealth and mobility is a way most people globally could at least deal with it.

And the US Republicans themselves are getting conflicted about things too:
http://hardware.slashdot.org/story/13/11/22/1716216/a-war-over-solar-power-is-raging-within-the-gop [slashdot.org]

Space settlement is another example of a future public good that an enlightened far-sighted government should be investing in. The USA has mostly turned it back on that. China and India seem to be forging ahead, as was the USSR earlier.

Still, a basic income would at least make it possible for the average citizen to contribute towards these public-minded projects (including better space navigation via pulsars) by having the free time to do so if so inclined.

And when they pull the mask off the Pulsar. . . (0)

Salgak1 (20136) | about 7 months ago | (#45682081)

. . . . the gang finds that it was Farmer Brown all the while !!!

I'm always impressed (0)

Anonymous Coward | about 7 months ago | (#45682083)

by how we can explore the universe from our computer chairs. Some people think the only way to explore the universe is to personally walk on the object. Good thing these people weren't around in the 19th century to find helium in the Sun's atmosphere or in the 1950s to find out what's underneath Venus' clouds.

Re:I'm always impressed (2)

barlevg (2111272) | about 7 months ago | (#45682239)

I agree with you that people erroneously assume that manned space exploration is done primarily for the purpose of scientific exploration. While it is certainly true--especially in previous eras--that exploration of our solar system is often best accomplished by intelligent and adaptable human beings as close to the "action" as possible, there's another reason why we need to develop capabilities for manned space flight: http://www.youtube.com/watch?v=xkj2lR9CT08 [youtube.com]

Ask ten different scientists about the environment, population control, genetics and you'll get ten different answers, but there's one thing every scientist on the planet agrees on. Whether it happens in a hundred years or a thousand years or a million years, eventually our Sun will grow cold and go out. When that happens, it won't just take us. It'll take Marilyn Monroe and Lao-Tzu, Einstein, Morobuto, Buddy Holly, Aristophanes .. and all of this .. all of this was for nothing unless we go to the stars.

Re:I'm always impressed (0)

Anonymous Coward | about 7 months ago | (#45682477)

Unfortunately, evolution is still happening, and in less than a million years there won't be a human species in any case. And what exactly does " It'll take Marilyn Monroe and Lao-Tzu, Einstein, Morobuto, Buddy Holly, Aristophanes .. and all of this .. all of this was for nothing unless we go to the stars." mean anyways? When you personally die, you won't remember any of these people either. Wouldn't life extension be the first priority then? Because otherwise you're just projecting your insecurities and neuroses onto future people. What gives you the right to decide that the future must be used to remember the past, specifically a white eurocentric middle-aged man's past?

Re:I'm always impressed (1)

occasional_dabbler (1735162) | about 7 months ago | (#45685211)

The examples were emotive. The real loss to the universe will be the maths and physics we've discovered, and DNA. These are worth preserving, if only so later intelligences can use them for comparison

Re:I'm always impressed (0)

Anonymous Coward | about 7 months ago | (#45685225)

So send out a plaque. Oh wait... But good to know all the Spacers have on their side is emotion.

Re:I'm always impressed (1)

scarboni888 (1122993) | about 7 months ago | (#45685581)

The second law of thermodynamics means that all of this is for nothing regardless of if we manage to escape the gravity well that birthed us before our star boils off the planet.

Since no information can travel between universes that means the heat death of THIS universe is the end of any coherent information whatsoever.

Not just atoms will fall apart but even protons will decay.

There may be a lot of time yet but entropy will win, in the end.

Re:I'm always impressed (1)

barlevg (2111272) | about 7 months ago | (#45685779)

Re:I'm always impressed (1)

scarboni888 (1122993) | about 7 months ago | (#45686757)

Or the Bible. Or whatever else it is you have to use to escape the truth on a day to day basis.

Fact of the matter is now that we can receive safe and effective sterilization procedures there's no real need for any further suffering or the furtherance of fairy tales in the vain attempt to shelter against the cold hard reality of the absolutely, unequivocally, and horrifiying nothing.

We can stop the madness.

I know I have.

Re:I'm always impressed (1)

barlevg (2111272) | about 7 months ago | (#45686861)

My point in posting that was simply that we don't know what advances in physics will arise in the next few billion years. Just because the Second Law seems unbreakable now doesn't mean it will always be that way.

Re:I'm always impressed (0)

Anonymous Coward | about 7 months ago | (#45689647)

Vanilla heat death of the universe is quite manageable though. If it turns out the proton decays, or that accelerating expansion leads to a point where bonds between atoms can no longer form, there might be a problem. But if not for those scenarios, computing devices can be constructed that operate slower and slower with time, and as a result could go on to compute for an infinite amount of time at an ever slower rate. There was some basic work done on this that shows, assuming human consciousness can be transfered to a machine (or just use an AI instead if not), it could not "die" even with the heat death of the universe.

Why is it? (1)

BisuDagger (3458447) | about 7 months ago | (#45682175)

That black holes are the punchline of every scientific joke.

Really? (1)

Anonymous Coward | about 7 months ago | (#45682191)

The moral of the story? It's not just black holes that get the asteroid munchies.
 
Massive bodies attract other masses in their local neighborhood? Wow. This is amazing information!

Re:Really? (1)

g01d4 (888748) | about 7 months ago | (#45682527)

Wow. This is amazing information!

It is, kind of. One might think the area around a pulsar would be fairly cleaned out and you've got to wonder where the asteroid came from and what kicked it in. While we've detected planets and asteroid/dust belts around stars, this might be the smallest extra-solar object ever detected.

Re:Really? (0)

Anonymous Coward | about 7 months ago | (#45682529)

Contrary to popular belief, the attraction of a pulsar/blackhole/etc is not enough to explain a collision. In a two-body system, a local mass will either form an elliptical orbit around the pulsar, or have already collided with it on its first orbit. From this we can deduce that the local mass must have been recently perturbed by another body first.

Re:Really? (0)

Anonymous Coward | about 7 months ago | (#45683465)

It is enough to explain it. While it might be more likely for a body to form an orbit it's certainly not unthinkable that something will hit sooner or later. If you want to dispute this you're going to need some serious citing as I think it's pretty apparent that blackholes and other large mass objects certainly do attract other mass.
 
And small body masses changing their orbit is not uncommon either.
 
I think you're just being obtuse in order to sound informed but the reality is that you're a moron.

Re:Really? (1)

mrsquid0 (1335303) | about 7 months ago | (#45685799)

Nope. The first anonymous coward is correct. Orbits do not suddenly change on their own. That would violate various conservation laws. The fact that an asteroid-mass object appears to have hit a pulsar means that something perturbed that astroid's orbit. This was probably an encounter with another asteroid.

Re:Really? (0)

Anonymous Coward | about 7 months ago | (#45689743)

In a classical two body system, if the orbits don't intersect surface of each other (which gets harder when both objects are small), then they will never hit each other. GR allows for energy to be radiated as gravitational waves, but unless both bodies are close and extremely dense/heavy (e.g. some combination of neutron stars and black holes), the decay rate of the orbit would involve timescales longer than the age of the universe. Otherwise you are stuck with angular momentum that prevents the two bodies from falling straight toward each other. If they get close enough to each other, an atmosphere around the star can slowly decelerate the asteroid, assuming it is not eroded or broken up before getting close enough to have any noticeable effect on the star. Otherwise, you need some third body to create more drastic changes, something to sling shot or exchange angular momentum with the asteroid so one thing get flung further out and the other further in.

This is an extremely important issue for neutron stars and black holes, as transport of angular momentum in accretion disks is a on going topic of research. Effects like the magnetorotational instability are critical for allowing material to actually fall from an accretion disk into a neutron star or black hole, as otherwise the exchange of angular momentum is too slow.

not surprising (2)

slashmydots (2189826) | about 7 months ago | (#45682281)

If an asteroid "landed" on earth, it wouldn't go back up either. So yeah, this isn't terribly surprising that other massive bodies om nom nom asteroids too.

Re:not surprising (1)

gl4ss (559668) | about 7 months ago | (#45682467)

but would we get longer days from massive asteroid collision?

Re:not surprising (1)

Anonymous Coward | about 7 months ago | (#45683193)

Yes. We certainly could. There are documented incidents of relatively trivial happenings slowing/speeding the Earth; earthquakes, tsunamis and the like.

Re:not surprising (1)

Immerman (2627577) | about 7 months ago | (#45687757)

Depends entirely on if it hits going east or west. If going east it's impact would increase the Earth's spin, shortening the day. Similarly the north or south component will impact the inclination of the Earth's axis depending on the season and whether the impact is on the day or night side of the planet.

Re:not surprising (1)

fredrated (639554) | about 7 months ago | (#45682883)

"massive bodies om nom nom asteroids"
Say what?

Re:not surprising (0)

Anonymous Coward | about 7 months ago | (#45683569)

Sadly, I understood that perfectly.

Re:not surprising (1)

RobertLTux (260313) | about 7 months ago | (#45683779)

Pretend the Pulsar is a Kitteh and the asteroids are cheezburger "sliders"

high score on asteroids (0)

Anonymous Coward | about 7 months ago | (#45682389)

Nice, but can it beat my high score of 156,111?

Pulsars evolve? (1)

CrunchyGammaRays (1967588) | about 7 months ago | (#45682525)

I wonder what happens to a pulsar when it gets fed a steady stream of matter. Does it collapse further and become something else, or will it burn everything and emit even more gamma? I have always assumed the latter, but from this it seems that the former may be true... Eh, just a random thought that has no place here.. Sorry, continue on.

Re:Pulsars evolve? (1)

mythosaz (572040) | about 7 months ago | (#45684285)

Based on my complete lack of understanding of these sort of objects, I imagine it's a race of sorts -- a contest between whatever intergalactic debris it might suck in versus its rate of burn.

Re:Pulsars evolve? (1)

Immerman (2627577) | about 7 months ago | (#45687831)

I would think that neutron stars likely eject very little matter - any incoming matter gets condensed until protons and electrons fuse into neutrons, which would then be unaffected by any of the electromagnetic disruptions that eject plasma from a "normal" star.

Hmm, though now I'm wondering how exactly a neutron star can maintain a magnetic field to begin with. Is it assumed to be ionized? Is their some sort of "quark soup" hocus pocus going on in it's core? And Google offers me no easy answers, grr.

Re:Pulsars evolve? (0)

Anonymous Coward | about 7 months ago | (#45689691)

A neutron star is not solid neutrons all the way through, as the pressure gets lower the closer you get to its surface. The pure "neutronium" eventually transitions to a very dense soup of protons and electrons as you increase your radius (and there is a bunch of amusing pasta themed names for all of the intermediate states in the transition). That really dense proton plasma has an extremely high conductivity, so it takes a long time for magnetic fields to move through it and for currents to dissipate. So any fields present in the original star or created in the collapse process get trapped. Strong electric and magnetic fields also allow for some particles to be accelerated to relativistic speeds, so there will still be some emission from a neutron star, not to mention the process of jet formation with accretion disks.

Re:Pulsars evolve? (1)

Immerman (2627577) | about 7 months ago | (#45689999)

From my research last night that does sound like it's part of the explanation. It also sounds like the neutrons themselves have a magnetic moment due to the charged quarks composing them. And it sounds like the neutron gas core of the star is moving into territories where our understanding of the nature of matter are still quite tentative. Curious thing to think of something that massive being more strongly governed by the quantum wavefunction equations of state than classical physics.

Pulsar Clocks (0)

Anonymous Coward | about 7 months ago | (#45682635)

Does that mean that the concept of using a Pulsar as a clock, no matter where you are or how fast you are travelling, might not be as accurate as previously thought?

Re:Pulsar Clocks (0)

Anonymous Coward | about 7 months ago | (#45683933)

that was never thought to start with.

Lucky workers... (0)

Anonymous Coward | about 7 months ago | (#45684029)

Enjoy while you can...

Here they got rid of the Past, now of Nature. Maybe the Past of far away objects will be next, and you will be as jobless as a Canadian postman (I hope Postman Pat did not move to Canada).

Stop anthropomorphising inanimate objects (1)

wonkey_monkey (2592601) | about 7 months ago | (#45685273)

Stop anthropomorphising inanimate objects. It's patronising to us, and they really hate it.

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