Comments on: September was Historic, astronomically

September was Historic, astronomically

spock — Wed, 03 Oct 2012 04:48:21 -0800

For the first time ever, a meteor has grazed in and out of Earth's atmosphere, slowing enough to become a temporary satellite that lasted a full orbit. In other astronomical news, a comet was discovered by a couple of Russian astronomers that appears to have all of the ingredients to be one of the greatest comets in our lifetimes, and maybe one of the greatest in human civilization's history. New comet might blaze brighter than the full Moon This will be the second great comet of 2013.

By: spock

spock — Wed, 03 Oct 2012 04:54:15 -0800

Before this discovery, we were looking forward to another great comet in the Spring of 2013 (known by the designation C/2011 L4 PANSTARRS ) This comet alone would be enough to make most comet lovers wet their pants, as it is expected to flirt with negative visual magnitudes in March 2013: C/2011 L4 ( PanSTARRS ) but it has now been joined by a very big brother that looks to wildly overshadow it. 2013 is going to be a once-in-a-lifetime year for comets.

By: Jimbob

Jimbob — Wed, 03 Oct 2012 04:56:11 -0800

"Ever"? Who says?

By: DU

DU — Wed, 03 Oct 2012 04:57:52 -0800

hang on a second.... OK, I just got back from my time machine and I confirmed: yes, the first time ever. So cool. And I can't wait to see these comets through my homemade telescope!

By: infini

infini — Wed, 03 Oct 2012 04:59:53 -0800

Do you think this was why the Mayan astronomer priests were having kittens?

By: caddis

caddis — Wed, 03 Oct 2012 05:07:15 -0800

WE ARE ALL GOING TO DIE ......... . . . (eventually)

By: GallonOfAlan

GallonOfAlan — Wed, 03 Oct 2012 05:08:08 -0800

'tis a portent!

By: ardgedee

ardgedee — Wed, 03 Oct 2012 05:14:45 -0800

PANSTARRS really should have been the name of a 1980s electronic pop act with a couple minor hits and one strong LP and whose fanbase is small but continues to be fiercely loyal to their memory thirty years along.

By: Burhanistan

Burhanistan — Wed, 03 Oct 2012 05:17:16 -0800

No death cults, please.

By: limeonaire

limeonaire — Wed, 03 Oct 2012 05:41:46 -0800

Ahh, and so it begins. [smiles a small, contented smile to self]

By: localroger

localroger — Wed, 03 Oct 2012 05:42:29 -0800

Aerobraking.

By: EndsOfInvention

EndsOfInvention — Wed, 03 Oct 2012 05:45:12 -0800

Skimmed over this post and for a second thought a comet had skimmed the atmosphere and entered orbit around the Earth.

By: eriko

eriko — Wed, 03 Oct 2012 05:46:18 -0800

By: Dr Dracator

Dr Dracator — Wed, 03 Oct 2012 05:50:58 -0800

I would settle for 1960s secret spy satellite with amazingly precise analog optics, rivaling modern digital equipment and entirely unknown outside of a couple of government agencies and some geocities web pages.

By: kinnakeet

kinnakeet — Wed, 03 Oct 2012 05:54:11 -0800

Jolly fun. Here's hoping this one meets expectations... or exceeds them.

By: eriko

eriko — Wed, 03 Oct 2012 05:55:53 -0800

From the last link. Sun on 28 November 2013, current predictions are of an object that will dazzle the eye at up to magnitude —16. That's far brighter than the full Moon. If predictions hold true then C/2012 S1 will certainly be one of the greatest comets in human history. I'm not one for hyperbole, but HOLY FUCK. Seriously, if this comet is sitting at magnitude -16, this would be unforgettable. The full moon is magnitude -12.7 to -12.9, call it -13. That's 15 *times* brighter than the full moon. That's a comet you can read by. If this comet is a tenth as bright as they're guessing, it'll be one of the greats. The last ultra-bright comet was Ikeya-Seki, which was clearly visible during the day when it topped at magnitude -10. This would be almost 250 times brighter.

By: DU

DU — Wed, 03 Oct 2012 05:56:39 -0800

Skimmed over this post and...orbited once before crashing into the comments section.

By: notsnot

notsnot — Wed, 03 Oct 2012 06:05:41 -0800

Holy crap. I think I may have seen a late chunk of this re-entering about midnight on the 22nd. It was headed west (as was I) somewhere over Kansas. Is that possible? At the time I just thought, "Huh, stray meteor."

By: ardgedee

ardgedee — Wed, 03 Oct 2012 06:12:14 -0800

Incidentally, wherever you are the weather's going to be overcast and rainy on November 28, 2013.

By: DU

DU — Wed, 03 Oct 2012 06:14:34 -0800

Comets are visible for days and often weeks or months on either side of the closest approach.

By: misteraitch

misteraitch — Wed, 03 Oct 2012 06:26:10 -0800

Previously.

By: elpapacito

elpapacito — Wed, 03 Oct 2012 06:26:36 -0800

if my memory serves, there's a significant risk... that the said ubercomet will be vaporized by sun before we get to see it at its brightest?

By: Skeptic

Skeptic — Wed, 03 Oct 2012 06:28:10 -0800

The Space Masters have decided to reboot the system. They didn't expect the mammals to be as much of a fiasco as the dinosaurs, but "Homo Sapiens" has shown them otherwise. Some terrestrial arthropods are showing promise, though.

By: aught

aught — Wed, 03 Oct 2012 06:28:30 -0800

For the first time ever, Almost certainly not, though it might be the first one to have been tracked by astronomers.

By: nfg

nfg — Wed, 03 Oct 2012 06:31:06 -0800

I saw the fireball mentioned from the west of Ireland, it was really quite stunning - about 15 or 20 pieces all burning intense orange and crumbling, strung out over maybe 20 degrees in the sky; they passed due west over the horizon all taking about 20s. We actually speculated at the time that it might have "skipped" off the atmosphere (like the daylight fireball of 1972). When it passed over us it was definitely traveling significantly slower than other meteors I've seen. I was so impressed with the sight that I'm trying to work on a painting of it at the mo!

By: Devils Rancher

Devils Rancher — Wed, 03 Oct 2012 06:33:50 -0800

Everybody has their roll of quarters ready, right?

By: Ghidorah

Ghidorah — Wed, 03 Oct 2012 06:36:22 -0800

So... dragons?

By: smirkette

smirkette — Wed, 03 Oct 2012 06:37:40 -0800

Well, I was looking for an excuse to take a road trip up the CA coast in November. This is it!

By: jet_manifesto

jet_manifesto — Wed, 03 Oct 2012 06:42:24 -0800

And thus the Old Ones return...

By: dances_with_sneetches

dances_with_sneetches — Wed, 03 Oct 2012 06:46:26 -0800

I, for one, welcome our new Triffid overlords.

By: metaBugs

metaBugs — Wed, 03 Oct 2012 06:49:40 -0800

Wow, that photo of the meteor passing behind the tower is fantastic. I love it for the incredible luck that helped create it, as much as for the image itself. I can still remember getting excited about Hale-Bopp as a kid, so if the two (!!) comets next year live up to expectations, it'll be ! My impression is that comets tend to be on the same orbital plane at the Earth, give or take, and so should be visible from both hemispheres. Is this right, or do I need to make travel plans? Also, what do you see if you look at a comet through a consumer-level telescope? I'd guess that you see a bigger version of the same white fog, but is there a chance of seeing any features, like the core(s)?

By: Iteki

Iteki — Wed, 03 Oct 2012 06:56:41 -0800

Is there some sort of mailing list or Facebook group I can join that will inform me of cool shit in the sky as it happens in my part of the world? As in "go out tonight and look up (and to the northwest). I would be willing to pay for something like this that worked reliably.

By: Shutter

Shutter — Wed, 03 Oct 2012 07:02:38 -0800

Iteki: These people have an App, satellite flybys, which claims it'll tell you when the ISS and whatnot should be visible. I haven't tested it yet, but I'm hopeful. I used to get emails for aurora sightings in my area, but I can't recall how that worked.

By: nfg

nfg — Wed, 03 Oct 2012 07:20:11 -0800

Heavens-Above is free and has excellent information on visible satellites (as well as other phenomena like comets).

By: Nelson

Nelson — Wed, 03 Oct 2012 07:23:20 -0800

I think it's fascinating that the best data we have about this event is a bunch of random folks who were out driving around and one of them pulled over by the side of the road and estimated the orbit by eyeballing it against the road. Oh and some folks who happened to see it a few hours later on the other side of the earth, and some guesswork that maybe it's the same object. Just seems surprising we don't have some whole-earth automated imaging. OTOH I just did a back of the envelope and realized that'd be really hard; either take zillions of cameras making a mosaic of the Earth or else some ridiculously detailed camera way high up in orbit.

By: Chrysostom

Chrysostom — Wed, 03 Oct 2012 07:30:57 -0800

C/2012 S1 will be officially named Comet Hamner-Brown.

By: mosk

mosk — Wed, 03 Oct 2012 07:35:38 -0800

posted by spock Fascinating. I mean, seriously: fascinating post, spock!

By: Cheezitsofcool

Cheezitsofcool — Wed, 03 Oct 2012 07:47:52 -0800

The timing of this couldn't be more perfect/terrifying, as I just watched Melancholia a few days ago.

By: spock

spock — Wed, 03 Oct 2012 07:52:39 -0800

It is worth noting that the great Daylight Comet of 1910 (often confused with Halley's Comet which also came around that year, but was not visible in daylight) came within .12 AU of the sun at perihelion. C/2012 S1 (ISON) is calculated to come within .012 AU (or 10x closer to the sun). Closer to the sun means more melting/out-gassing and thus one HECK of a tail. Yes sungrazing comets can be broken into piece or even, if their mass is insufficient, melt completely. However, this would seem unlikely for C/2012 S1 (ISON), given its apparently good-sized mass - based upon how far away it still was upon discovery. It's parabolic orbit makes astronomers think this is its first trip around the sun after falling out of the Oort Belt.

By: spock

spock — Wed, 03 Oct 2012 08:19:08 -0800

PS... next time you count your blessings, don't forget to include the earth's atmosphere.

By: pracowity

pracowity — Wed, 03 Oct 2012 08:49:27 -0800

Comets are visible for days and often weeks or months on either side of the closest approach. There will be clouds for the duration.

By: arcticseal

arcticseal — Wed, 03 Oct 2012 08:51:47 -0800

There will be clouds for the duration. We prefer the term "cloaking".

By: Podkayne of Pasadena

Podkayne of Pasadena — Wed, 03 Oct 2012 08:56:01 -0800

Yah ... I call B.S. on the brightness prediction. It makes for great page hits to say it will be "teh greatest comet evah!" but you'll note that Astronomy Now magazine never actually reports who is making that brightness prediction. This is probably because there is no established science that can make such a prediction at his stage of the comet's discovery and orbit. None of which will keep such webzines from inaccurately reporting bizarre predictions in order to keep the page hits up.

By: Devils Rancher

Devils Rancher — Wed, 03 Oct 2012 08:59:06 -0800

PS... next time you count your blessings, don't forget to include the earth's atmosphere. I gaze in wonder at the atmosphere all the time. You know how people will occasionally comment when I big jet flies over - "How do they stay up there?" I usually reply that "Air is thicker than it looks." I blame psychedelics for the occasional moment of existential dread, when I'm outside and I suddenly realize that there is nothing between me and the cold, dark vacuum of space other than a couple miles-worth of air.

By: Podkayne of Pasadena

Podkayne of Pasadena — Wed, 03 Oct 2012 09:00:17 -0800

Also, what do you see if you look at a comet through a consumer-level telescope? I'd guess that you see a bigger version of the same white fog, Pretty much. You get better tail definition but that's about it/ but is there a chance of seeing any features, like the core(s)? No chance at all. The core is completely shrouded by gas and dust

By: spock

spock — Wed, 03 Oct 2012 09:05:40 -0800

"Blessed are the pessimistic, for they shall never be disappointed." (P of P) Cynicism is to be expected on the Blue. I hope it isn't considered urinating in your Cheerios to mention that, while the comet was only recently discovered, they went back through pre-discovery sky survey images and found it going back some 9 months. This gave them over 50 data points from which to plot its orbit. Certainly comets are not always predictable, and there have been disappointments in the past, but the comet nerds on the Comets-ml mailing list are scientists - not bloggers looking for web hits - and they are saying that if they drew up a fictitious "dream comet" it would look like the data so far on this one.

By: BeeDo

BeeDo — Wed, 03 Oct 2012 09:08:27 -0800

Awesome.

By: ChuraChura

ChuraChura — Wed, 03 Oct 2012 09:27:50 -0800

Is "greatness" determined by brightness?

By: spock

spock — Wed, 03 Oct 2012 09:42:52 -0800

In a nutshell, yes.

A Great Comet is a comet that becomes exceptionally bright. There is no official definition; often the term will be attached to comets that become bright enough to be noticed by casual observers who are not actively looking for them, and become well known outside the astronomical community. Great Comets are rare; on average only one will appear in a decade. While comets are officially named after their discoverers, Great Comets are sometimes also referred to by the year in which they appeared great, using the formulation "The Great Comet of...", followed by the year. Source - Wikipedia

Here is a foremost comet expert's list of "The Bright Comets", (seen between 1800 and 2000 that attained an observed maximum brightness of magnitude 0 or brighter, together with a few additional objects of special interest). So 2013 will be exceptional. Rather than one such object "per decade" we will have two in the same calendar year.

By: eriko

eriko — Wed, 03 Oct 2012 09:46:58 -0800

Is "greatness" determined by brightness? It's definitely a factor, but what really makes for a "great comet" is basically being obviously visible to a large fraction of the human population. Brightness, long tails, and long periods in the sky all factor in. Closeness at perihelion tends to favor brightness -- there is a family of comets (the Kreutz Sungrazers) that have perihelions that are very close to the sun, often under one solar radius. A comet in the distant pass came in and broke up, the fragments are still about today, and many of them are considered great comets, including X/1106 C1, the Great Comet of 1106. X/1106 C1 was a subfragment of the original comet, fragments of X/1106 C1 became C/1882 R1 (The Great Comet of 1982) and Comet Ikeya-Seki (C/1965 S1, the brightest comet in the last century.) Brian Marsden of the MPC has done a lot of work finding the fragments of the progenitor comet. The term may be overused of late, but there's no doubt that Hale-Bopp and McNaught deserved the acclaim. Anything that's obviously visible over city skyglow, or in the daytime sky, is probably going to qualify.

By: Chrysostom

Chrysostom — Wed, 03 Oct 2012 09:51:08 -0800

spock: "Certainly comets are not always predictable, and there have been disappointments in the past" I was hoping for a Kohoutek tag on this post.

By: pracowity

pracowity — Wed, 03 Oct 2012 10:04:20 -0800

Kohoutek was my first comet disappointment. The only one I've ever seen that was really lovely and comety for me was (*checks wikipedia*) either Hale-Bopp or Hyakutake. I think it must have been Hale-Bopp.

By: bukvich

bukvich — Wed, 03 Oct 2012 10:07:12 -0800

Hale Bopp was fifteen years ago. Time flies. Does anybody have a good book recommendation about these poor souls? There were like ten thousand tasteless jokes on the internet after about going to the next level. I also agree that predicting a great comet is bogus. You have to have some 20/20 hindsight for a case like this.

By: marvin

marvin — Wed, 03 Oct 2012 10:53:55 -0800

Melancholia.

By: bukvich

bukvich — Wed, 03 Oct 2012 10:57:05 -0800

Do's last chance video. Aye aye aye aye aye aye aye

By: theodolite

theodolite — Wed, 03 Oct 2012 11:09:54 -0800

Wikipedia sez C/2012 S1 will whip by Mars at a distance six times closer than Earth. The Curiosity photos are going to be just completely rad.

By: punkfloyd

punkfloyd — Wed, 03 Oct 2012 11:23:50 -0800

Worst. Moon. Ever.

By: Kevin Street

Kevin Street — Wed, 03 Oct 2012 13:12:31 -0800

"It's parabolic orbit makes astronomers think this is its first trip around the sun after falling out of the Oort Belt." That's just amazing. It's been out there for 4.5 billion years, and thanks to some subtle interplay between gravitational fields is only now coming close enough to be seen.

By: homunculus

homunculus — Wed, 03 Oct 2012 13:59:59 -0800

In other news: International space station veers to avoid space junk

By: TheWhiteSkull

TheWhiteSkull — Wed, 03 Oct 2012 14:05:03 -0800

Remember: "Green sky at night/The Mayans were right!"

By: ovvl

ovvl — Wed, 03 Oct 2012 17:36:06 -0800

The timing of this couldn't be more perfect/terrifying, as I just watched Melancholia a few days ago. I would love to hear a brief scientific critique of the astronomy in the movie 'Melancholia', which had nice art direction, and the usual Von Trier dynamics. I thought it was one of the more interesting movies of last year.

By: spock

spock — Wed, 03 Oct 2012 17:52:44 -0800

Let me Google that for you: http://www.rationalskepticism.org/astronomy/science-of-melancholia-t22920.html, http://www.slate.com/articles/health_and_science/explainer/2011/11/lars_von_trier_s_melancholia_what_are_the_chances_of_a_planetary_collision_.html, http://answers.yahoo.com/question/index?qid=20111110034523AAsmEtx

By: Twang

Twang — Wed, 03 Oct 2012 19:28:48 -0800

I call B.S. on the brightness prediction. Of course this comet is very likely the one predicted by the Mayans in a text located very recently at a famous site. A team of reputable experts reports that the trajectory of this brilliant comet is depicted at Nazca. Another expert reports it's shape is that of the well-known Underwater Aquatic Object or UAO recently mysteriously discovered deep under the surface of the Baltic Sea. SEND your donations TODAY.

By: roystgnr

roystgnr — Wed, 03 Oct 2012 19:43:57 -0800

Here's the predictions from aerith.net I found. The upside: they do think it'll be brighter than the full moon. The downside: it looks like it'll be practically next to the sun (in Libra) at the time, so the relative brightness might not be all that spectacular.

By: Pruitt-Igoe

Pruitt-Igoe — Wed, 03 Oct 2012 21:45:00 -0800

fireball of 1972 TIL that wasn't just a Deep Purple album.

By: homunculus

homunculus — Wed, 03 Oct 2012 22:30:38 -0800

Do you think this was why the Mayan astronomer priests were having kittens? I think they were presciently pissed about this: Archaeologists Disturb Tomb of Badass Mayan Warrior Queen, Prove That Science Has Learned Nothing from Hollywood

By: spock

spock — Thu, 04 Oct 2012 05:32:20 -0800

roystgnr: You are concentrating too much on the head of the comet and forgetting the tail (which points away from the sun). Sunrises close to perihelion will be preceded by an impressive "tailrise" - a shaft (or maybe a fan) of light coming up from out of the horizon.

By: Podkayne of Pasadena

Podkayne of Pasadena — Thu, 04 Oct 2012 08:19:31 -0800

but the comet nerds on the Comets-ml mailing list are scientists - not bloggers looking for web hits - Oh My - Scientists!! Yeah. Do not mistake knowledge for cynicism or misplaced enthusiasm for scientific fact. The brightness of a comet will depend on many factors (the least of which is it's orbit) including what the comet is composed of and how much volatiles it actually contains neither of which it is possible to ascertain or even guess at at this point. A mailing list is not a published journal and people talking on a mailing list are not putting their professional reps on the line - they are just people talking. When you are an astronomy nerd such as I and have lived as long as I then you begin to see a pattern which is that less than 1/5th of "it's gonna be a big one!" comet predictions actually come true (cough couch... Kohoutek.. cough...Hale Bopp...cough...). Even Halley's was kind of a downer last time. You can't possibly predict brightness at this point or even make an accurate guess. It seems, from past predictions that no one really knows what's happening brightness wise until a couple months prior to perihelion which won't be until late next summer.

By: Sokka shot first

Sokka shot first — Thu, 04 Oct 2012 08:40:08 -0800

you begin to see a pattern which is that less than 1/5th of "it's gonna be a big one!" comet predictions actually come true (cough couch... Kohoutek.. cough...Hale Bopp...cough...) I'm sure this skepticism is well-founded, but Hale-Bopp was awesome, so I find the harrumphing a little mystifying.

By: ovvl

ovvl — Thu, 04 Oct 2012 20:39:00 -0800

Thanks for the data, Spock. I was kinda hoping for a personal touch.

By: charlie don't surf

charlie don't surf — Thu, 04 Oct 2012 21:53:00 -0800

The timing of this couldn't be more perfect/terrifying, as I just watched Melancholia a few days ago. I have been referring to 2012 DA14 as Asteroid Melancholia. BTW, I saw that movie and I wonder if my reaction was typical. I was about 10 minutes in, when I became terribly impatient to see all those horrible people obliterated.

By: dhartung

dhartung — Fri, 05 Oct 2012 00:47:06 -0800

I agree that Hale-Bopp was awesome. One factor at play is the number of people who live in cities, which outside of say North Korea are heavily light-polluted. You just can't see things in the sky the way you used to, unless you're in a very rural area. I went to what I thought was a very dark location for the 2011 Perseids and the light pollution from the neighboring (really, almost surrounding) city meant I saw virtually nothing. I had to drive some ten miles out of town before I began to see the shower well. The number of people who will do this, even for a comet, is vanishingly small. I also think there's an issue something like the Nate Silver poll thread stuff. We just know too much about comets in advance, too far in advance, and thus the astonishment and surprise are lost. Of course predicting actual visibility/greatness is a bit of a crapshoot, but I don't think that's actually a bug here. Those mailing list participants are posting with hope, not advising us of a factual future. I don't think this is really that different from, say, baseball prognosticators looking at some 19-year-old phenom who will turn out not to be Hank Aaron but Clint Hartung. It just comes with the territory and ultimately should be viewed as, well, part of the fun.

By: spock

spock — Tue, 09 Oct 2012 15:32:45 -0800

If you didn't think that Hale-Bopp was awesome then your modern sensibilities would seem to require calling something a Great Comet only if it can overcome your city's light pollution. I could see Hale-Bopp from out my kitchen window with the lights in the house on. I don't know of a comet that was more impressive (at least in the Northern Hemisphere) in my lifetime.