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Space Science

Comet Unexpectedly Brightens a Millionfold 276

Posted by kdawson
from the portents-in-the-heavens dept.
swordgeek writes "Comet 17P/Holmes, a relatively obscure and (until a few days ago) dim object, has suddenly flared to be literally a million times brighter, going from magnitude 18 to 2.8. It is just outside of the constellation Perseus, which puts it high in the sky and ideal for viewing at this time of year. The comet still appears starlike even in binoculars but should grow to several arcminutes across over the next few nights. The comet is now readily visible to the naked eye. This is a completely unexpected once-in-a-lifetime event, so get out your finest optics (even if it's just your eyes) and go comet watching!"
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Comet Unexpectedly Brightens a Millionfold

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  • i don't think we've seen a really big bright comet in how long? hasn't it been decades, or centuries even? anywhere in the world?

    i mean a really big bright one that eats the whole sky

    we need a big bright comet because history teaches us that warring factions oftentimes stop their fighting and lay down their arms when shocked at the sight

    so we need a big bright comet pronto
  • by camperdave (969942) on Thursday October 25, 2007 @10:01AM (#21112851) Journal
    Perhaps I'll go look. Despite all the hype, Halley was a bust. Kohoutek may have been the comet of the century, but that was last century. I hope this one doesn't disappoint.
    • by rk (6314)

      I thought Hale-Bopp [wikipedia.org] was spectacular. You could clearly see the two tails and it was close enough that scientists discovered a third cometary tail.

      And to the British guy who asked: I think the constellation Perseus is the same constellation in the UK. You may be screwed if you're in Australia though. I don't think you can see Perseus from there, but I'm not sure.

    • Re: (Score:3, Interesting)

      by hypnagogue (700024)

      Despite all the hype, Halley was a bust.

      Baloney. It was beautiful in March and April 1986, by far the best comet views in my lifetime, with a bright detailed tail 8 degrees long. Hyukatake and Hale-Bopp were good, but not that good.

      Let me guess, you went out to see Halley in October or November of 1985, before perihelion, long before peak, when it was in the night sky. Sorry, the views were in the spring, in the morning sky. Just like they were telling folks on the news; no one listened.

    • This comet isn't exactly one to get hyped about. It's not that bright. Magnitude 3 is about as bright as the Little Dipper. You won't see it from the city and you have to know where to look to identify it from better conditions.

      Of course, naked eye comets always get a brief mention in the news, even when dim, but this one caught attention because of the dramatic increase in brightness. It's all the more surprising when you consider that this is a short period comet in a relatively circular orbit. It make
  • Why? (Score:2, Interesting)

    by squoozer (730327)
    Does anyone have any idea why this comet has suddenly got so much brighter? Presumably it is flying past a star but surely it would do this on a fairly regular basis.
    • Re:Why? (Score:5, Informative)

      by jamie (78724) * Works for Slashdot <jamie@slashdot.org> on Thursday October 25, 2007 @10:08AM (#21112957) Journal

      Well, the only star it's flying near is the big yellow one you see in the daytime. I haven't seen anything about the reason it got brighter, but my guess would be it has an icy core that has been gradually heating internally as it orbited closer to the sun, until suddenly it burst out as steam. If that's the case, maybe it'll get brighter as it gets closer and warmer... or maybe the lid's been taken off the pot and after a day of spewing a ton of stored-up H2O now it'll settle down and get dimmer.

      (Like a balloon when something bad happens!)

      • Re: (Score:3, Informative)

        by Anonymous Coward
        Nope. This comet made its closest approach to the sun back in May. It's now moving away from the sun. It also follows a relatively circular orbit compared to most bright comets, so significant changes in brightness are unexpected.

        However, there may have been an unusually large pocket of vapor that form some reason burst out at this point (out-gassing), or it might have been hit by a smaller object.
    • Re: (Score:3, Informative)

      Does anyone have any idea why this comet has suddenly got so much brighter? Presumably it is flying past a star but surely it would do this on a fairly regular basis.

      Comets appear bright because they start to evaporate as they approach the sun, and the sun illuminates the evaporating gas and dust.

      The best guess as to why this one has suddenly brightened so much is that it has either broken apart or experienced a sudden outgassing for some other reason.

      BTW, the comets we see are gravitationally bound to o

    • by Zocalo (252965)
      The reason thought most likely is that the core has broken up, so this may turn out to be the comet's last trip around the sun as anything other than a cloud of rocky fragments.
    • Re: (Score:3, Funny)

      Obviously, It's coming right for us!
    • by SpacePunk (17960)
      It got brighter because it's firing retro rockets that'll put it on a collision course with Earth in 2012. /it would be soooo screwed up if I were right.
    • Thermal pulse (Score:5, Informative)

      by mdsolar (1045926) on Thursday October 25, 2007 @10:33AM (#21113347) Homepage Journal
      This comet orbits between 2.2 and 5.2 AU and it's last closest approach to the Sun was in May, 2007: http://en.wikipedia.org/wiki/17P/Holmes [wikipedia.org]. An AU is the average distance between the Sun and the Earth.

      Comet crusts, the dark stuff that is left over after the ice sublimates, are thought to conduct heat slowly. One theory on why we see outbursts as comets move away from the Sun, as this one is doing, is that the warming pulse from the closest approach takes time to sink down to a reservior of carbon monoxide gas which then sublimate internally and blows off fairly large chunks of the comet. Another theory is that the same thermal pulse reaches a reservior of amorphous water ice, which is more common in space than crystalline ice and thus might be present in comets since their formation. When amorphous ice is warmed, it will become crystalline and release energy because the ordered state of crystaline ice is a lower energy state. This can lead to a chain reaction of further crystallization and energy release that could lead to enough warming to cause sublimation in the interior and then do the same kind of thing as in the carbon monoxide scenario.
      --
      Get your power from the Sun for what you already pay now: http://mdsolar.blogspot.com/2007/01/slashdot-users-selling-solar.html [blogspot.com]
    • by njfuzzy (734116)
      Flying past a star? Stars are too far apart for us to see anything flying between them. Even at the speed of light, it takes years to go between even the closest of star systems. Comets are small hunks of ice and dirt, orbiting our star in unusual orbits originating in a cloud of cold gunk way beyond the planets. More likely, it's physical composition was disrupted somehow, causing it to be more volatile.
    • Re: (Score:3, Funny)

      by wximagery95 (993253)
      Does anyone have any idea why this comet has suddenly got so much brighter?

      Global warming.
  • by 140Mandak262Jamuna (970587) on Thursday October 25, 2007 @10:05AM (#21112915) Journal
    I remember a group of people waiting for you. Some 32 people in some large farm house or something in California. All wearing some kind of black clothing and Nike shoes. They took your promise to come in 1999 or so and committed suicide but you are coming so late. OK atleast the rest of the believers can now die and meet you.
    • by jollyreaper (513215) on Thursday October 25, 2007 @10:10AM (#21112971)

      I remember a group of people waiting for you. Some 32 people in some large farm house or something in California. All wearing some kind of black clothing and Nike shoes. They took your promise to come in 1999 or so and committed suicide but you are coming so late. OK atleast the rest of the believers can now die and meet you.
      I can't take credit for the lyrics but they're still funny!

      Song Lyrics:
      Magic Comet Ride

      (Parody of Magic Carpet Ride by Steppenwolf)

      I like to dream
      Yes, yes
      About flying around in a space machine
      When a big blue ball appears in the night
      Our leader says that the time is right
      Hale Bopp draws near
      Clean the house and pack that gear

      Well, UFO is right behind
      Why don't you come with me, boys and girls
      On a magic comet ride
      Well, UFO's got a extra seat
      Why don't you take a trek with me?
      Beam us up, we'll visit ET

      Grab a ride, girl
      Say good bye, world
      Let Hale Bopp take you away

      Last night I packed a travel sack
      And said goodbye on video tape
      Before the ship could come for me
      Some witch doctor had to take my nuts away
      I donned a gown
      Brand new shoes from Niketown

      Well, you won't know if you stay behind
      Why don't you come with me, cyber geek
      On a magic comet ride
      We'll follow Doe and you will see
      Why don't you go to sleep with me?
      This plastic bag will set you free

      Say goodbye, world
      Log your last URL
      Let the ship take you away

      Well, UFO is right behind
      Why don't you come with me, boys and girls
      On a magic comet ride
      Well, UFO's got an extra seat
      Why don't you take a trek with me?
      Beam us up, we'll visit ET (Marcus Tee)
  • Odd behavior (Score:5, Interesting)

    by Muad'Dave (255648) on Thursday October 25, 2007 @10:05AM (#21112929) Homepage
    According to SpaceWeather.com [spaceweather.com], not only did the comet brighten unexpectedly, it "... has no tail, [and] a remarkable golden color ...". Unless the geometry of the sun-earth-comet trio is such that the tail is pointing directly away from the earth, you'd think there'd be a massive tail given the million-fold increase in brightness.
    • by Alioth (221270)
      Of course, we won't see the tail because what They are not telling us is that it's headed directly for us - and that means that you of course won't see the tail, and we are all going to be extinct by next Friday!

      (In less paranoid mode, we've had a good long period of settled weather with nice clear skies. As soon as something new and interesting shows up in the sky? A week's unsettled cloudy weather is forecast! Typical.)

      • Don't worry, NASA is readying two shuttles right now, and Ben Affleck and Bruce Willis are on the way to the Cape as we speak...
      • Re:Odd behavior (Score:5, Informative)

        by aadvancedGIR (959466) on Thursday October 25, 2007 @10:48AM (#21113649)
        Just a few facts to ruin the joke.
        -If a comet is heading directly for us, don't worry. If it is heading where we will be by the time it gets there, on the other hand...
        -The comet tail is almost not related to its trajectory, but mostly to the direction of the solar wind hitting it, you can approximately draw a line Sun->comet->tail.

        So odds are that if we ever have to collide with a comet, we will most likely be idealy placed to see its tail just before the collision.
    • by Tmack (593755)

      According to SpaceWeather.com [spaceweather.com], not only did the comet brighten unexpectedly, it "... has no tail, [and] a remarkable golden color ...". Unless the geometry of the sun-earth-comet trio is such that the tail is pointing directly away from the earth, you'd think there'd be a massive tail given the million-fold increase in brightness.

      More proof that its no comet, but a spaceship firing retro rockets!

      Tm

    • by khallow (566160)
      Recall that the comet used to be magnitude 18. It doesn't "have" a tail because you can't see that initial tail. I wouldn't be surprised if it takes some time for the material currently being ejected to sort into a tail. The solar wind has low density and this pulse of material initially will have a relatively high density. It will get blown out into a tail over time.
    • by dintech (998802)
      has no tail

      That's because it's obscured. It's coming right for us!
    • by TexVex (669445)

      "... has no tail, [and] a remarkable golden color ..."
      Maybe those Heaven's Gate folk drank the Kool-Aid for the wrong comet!
  • WARNING (Score:5, Funny)

    by LiquidCoooled (634315) on Thursday October 25, 2007 @10:05AM (#21112931) Homepage Journal
    The comet is now readily visible to the naked eye.

    WARNING
    Do not look into the comet with your remaining eye.
    • Re:WARNING (Score:4, Funny)

      by R2.0 (532027) on Thursday October 25, 2007 @10:29AM (#21113299)
      A coworker bought a balisong (butterfly knife) as a youth, and being a methodical chap, bought "The Balisong Book", or somesuch.

      The instructions started out with "First, take off the blade of the knife prior to practicing, or you will cut yourself". Being young and cocky, he ignored it and started playing with it. After cutting his hand rather badly, he decided to consult the book again.

      The next line read "Now that you have bandaged your hand, tape off the knife edge like the previous instructions said".
  • by saudadelinux (574392) on Thursday October 25, 2007 @10:13AM (#21113035)
    Where's the Argo/Yamato? Tell 'em to power up the Wave Motion Gun to deal with this intergalatic menace!
  • so get out your finest optics (even if it's just your eyes) and go comet watching!"


    It's raining and overcast here, you insensitive clod!

    (and always is for any significant astronomical phenomenon)
  • I'm not familiar with the scale used to measure magnitude so I looked it up in Wikipedia. http://en.wikipedia.org/wiki/Apparent_magnitude [wikipedia.org] Can anyone explain to me why it goes -1.7, -0.7, 0, -0.24, 3, 4.6...?
    • by Bob54321 (911744)
      My guess is wikipedia has a mistake. Unlikely I know, but there have been rumors of one or two cases of misinformation previously. Well at least that link clear up why going from 18 to 2.8 is getting brighter.
    • by Myrano (952282) on Thursday October 25, 2007 @10:28AM (#21113271)
      Magnitude is a log scale, with brighter objects having lower magnitudes. Like so much in astronomy, the reason is historical: when the first guy (Greek, probably) decided to categorize stars by brightness he said the brightest stars should be first magnitude, the next brightest second, and so on. Because of the nature of the human eye, the scale is logarithmic. Objects brighter than what this guy considered first magnitude thus have a magnitude of less than one, or even less than zero.

      The numbers are funny (rather than -1, 0, 1, 2) because they're giving you sample objects so you can get an idea about the range of the scale.

      Hope that helped!
  • Er, where? (Score:4, Insightful)

    by sm62704 (957197) on Thursday October 25, 2007 @10:32AM (#21113325) Journal
    ...high in the sky and ideal for viewing at this time of year.

    On what part of the planet? Northern hemosphere or southern? The Americas or Asia? What time of night (or day)?

    In 1974, the American media were excitedly predicting a very bright comet named Kahoutek, and then when it appeared wrote how dissapointing the show was, that it wasn't even visible.

    I was in Thailand that year, Kahoutek drowned out all the stars in half the sky there.

    Some of you folks need to learn that the internet is a global phenomena and not restricted to your own country. Is this thing visible in my country (US)? What part of the sky, and what time? If I can see it, people in Australia can't.

    -mcgrew
    • by Riktov (632)
      The summary says it's in the constellation Perseus. If you can figure out where Perseus is, there are simple ways to figure out when and where you'll be able to see it from your location.

      On the other hand if you don't know where Perseus is, no amount of additional information will help you find the comet.
    • by papasui (567265)
      Fuck man you are too old to be on this website.
    • by Don853 (978535)
      I'm curious how that worked, since unless the comet was only bright during a 12 hour window it shouldn't have been any more visible in Thailand than America. TFA also mentions that the comet was viewed in Barcelona, New Mexico, and Yokohama, and explicitly states that it should be visible in the entire northern hemisphere.
    • by Riktov (632)
      The clock time during which a celestial object is in the sky on any day is essentially the same anywhere in the world. The angle of its path relative to the horizon, and thus rising and setting time, varies with latitude, but the time it reaches its highest point (zenith) in the sky will be at the same clock time. Just like the sun at noontime.

      Depending on latitude, its path through the sky may be entirely below the horizon and thus invisible. For example, the Little Dipper "rises", "sets", and "reaches zen
  • Ill have time this weekend, I think ill get the telescope out and see what I can see.

    It is always fun to check out new objects that show up in the sky. ;)
  • by clickety6 (141178) on Thursday October 25, 2007 @10:39AM (#21113467)


    You think that's unexpected?

    Wait until it suddenly changes direction!

    Now thatwill be unexpected!

  • by yeremein (678037) on Thursday October 25, 2007 @10:47AM (#21113617)
    here [flickr.com]. There was no visible tail, just a fuzzy circle.
  • by east coast (590680) on Thursday October 25, 2007 @10:48AM (#21113647)
    So that's why it's going to be cloudy over my area for the foreseeable future?

    Never fails.
  • It's firing at us?
  • Great scale (Score:3, Funny)

    by sacrilicious (316896) on Thursday October 25, 2007 @11:06AM (#21113891) Homepage
    literally a million times brighter, going from magnitude 18 to 2.8.

    Dr Evil: ... and so we will demand... one million dollars! (*laughs evilly*)
    Henchman: Um, well, it turns out that a million dollars isn't so much money any more.
    Dr Evil: Hmm. In that case... we will demand... fifty cents!!!

  • All Hail Galactus, Devourer of Worlds!
    • by njfuzzy (734116)
      Everyone is saying how Radd it was when the comet was Heralded. The danger will be Fantastic, but hopefully Ultimately it will be Nullified.
  • taking out another million or two Aku'Ultan.
  • has suddenly flared to be literally a million times brighter,

    It's the Silver Surfer! Aaaaah, we're all gonna die when the giant cloud-thing comes and eats our planet.

    Last call.

  • by trongey (21550) on Thursday October 25, 2007 @12:22PM (#21115155) Homepage
    The comet hasn't brightened. What you're seeing is the afterglow from the nuclear explosion that Bruce Willis set off yesterday.
  • by kmahan (80459) on Thursday October 25, 2007 @12:45PM (#21115511)
    Obviously a ship starting its deceleration burn.
  • by N0GNU (238662) on Thursday October 25, 2007 @01:53PM (#21116571)
    The /. title "Comet Unexpectedly Brightens a Millionfold" demonstrates a common mistake.

      Each "fold" means a doubling, or 2 to the n'th power. For example, three-fold is 8-times. Take a piece of paper and fold it three times- unfold it and count the number of rectangles outlined by the creases. This is where the expression actually came from...

      People incorrectly use the "fold" term because they think it sounds more intelligent, but they demonstrate their ignorance by misusing it.

      A brighting of 2 to the millionth power would be so massive that we and our entire solar system would be almost instantly vaporized and blown away by the photons striking us.

    ron
  • by swordgeek (112599) on Thursday October 25, 2007 @03:15PM (#21117717) Journal
    I'm slightly appalled.
    I write up what I consider to be an interesting story for /. readers, check my grammar and links, and then click submit. Lo and behold, it gets accepted. Cool!

    Then I read what I supposedly wrote, and find that words have been put in my mouth. Specifically:

    "The comet still appears starlike even in binoculars but should grow to several arcminutes across over the next few nights. "

    I did NOT write that. I didn't suggest it. The comet does NOT appear starlike in binoculars at all--it's quite a clear extended disk. ONE person quoted in Sky & Telescope believes that it will expand to several arcminutes in size, but that's strictly conjecture.

    Furthermore, I didn't use the word "millionfold" in my subject line. That was kdawson again. /. editors: If you're going to actually edit submissions (and why start now, after ignoring fundamental grammatical errors and duplicate stories for a decade?) then get it right!

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