Lulin and Galaxies (2009 March 7)

[orin stepanek]

http://apod.nasa.gov/apod/ap090307.html

I think comets are neat; I just wish there were more naked eye views ( closer encounters) that came around.

Orin

[apodman]

I think comets are neat ...

Agreed.

... I just wish there were more naked eye views (closer encounters) that came around.

The only trouble with that is a getting hit by a big one more often. Of course the big one isn't going to hit in my lifetime (probably) anyway, so go ahead and enhance the view - send some massive probes through the Kuiper belt and Oort cloud to perturb some of those lazy non-participating comets into fascinating Earth-grazing orbits. Or, to be safe, supplement the real comets digitally like the tv view of fireworks at the 2008 Olympics.

[neufer]

... I just wish there were more naked eye views (closer encounters) that came around.

The only trouble with that is a getting hit by a big one more often. Of course the big one isn't going to hit in my lifetime (probably) anyway, so go ahead and enhance the view - send some massive probes through the Kuiper belt and Oort cloud to perturb some of those lazy non-participating comets into fascinating Earth-grazing orbits. Or, to be safe, supplement the real comets digitally like the tv view of fireworks at the 2008 Olympics.

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<<Off on a Comet (French: Hector Servadac) is an 1877 science fiction novel by Jules Verne. The story starts with a comet that touches the Earth in its flight and collects a few small chunks of it. Some forty people of various nations and ages are condemned to a two-year-long journey on the comet. They form a mini-society and cope with the hostile environment of the comet (mostly the cold). The size of the 'comet' is about 2300 kilometers in diameter - far larger than any comet or asteroid that actually exists.>>
----------------------------------------
The 36 inhabitants of Gallia include a German Jew, an Italian, three Frenchmen, eight Russians, 10 Spaniards, and 13 British soldiers.

The main characters are:

* Captain Hector Servadac of the French Algerian army
* Laurent Ben Zoof, Servadac's aid
* Count Wassili Timascheff of Russia
* Lt. Procope, the commander of Timascheff's yacht, Dobrina
* Isaac Hakkabut, a German trader
* Nina
* Pablo
* Colonel Heneage Finch Murphy and Major Sir John Temple Oliphant of Britain's Gibraltar garrison.
* Palmyrin Rosette, the French discoverer of the comet and previously Servadac's teacher.
----------------------------------------
<<From the beginning Verne had problems with this novel. Originally he intended that Gallia would crash into the earth killing all on board. This may have been the motivation for his ghoulish and rather unfunny joke naming the hero "Servadac" with the mirror of the French word cadavres (="corpses"), predicting all would die on the "return". His publisher Hetzel would not accept this however, given the large juvenile readership in his monthly magazine, and Verne was forced to graft a rather unsatisfying ending onto the story, allowing the inhabitants of Gallia to escape the crash in a balloon.>>

----------------------------------------------------

<<When Hector (Ἕκτωρ, "holding fast") sees Achilles coming, he turns and runs three times around the walls of Troy, then makes his stand. Achilles stabs his spear through Hector's throat. After Hector died, Achilles then slit Hector's heels, and took the girdle that Ajax had given him and passed it through the slits of the heels. He then fastened the girdle to his chariot and drove [Hector's corpse] through the DUST to the [Greek] camp.>>

[orin stepanek]

I think comets are neat ...

Agreed.

... I just wish there were more naked eye views (closer encounters) that came around.

The only trouble with that is a getting hit by a big one more often. Of course the big one isn't going to hit in my lifetime (probably) anyway, so go ahead and enhance the view - send some massive probes through the Kuiper belt and Oort cloud to perturb some of those lazy non-participating comets into fascinating Earth-grazing orbits. Or, to be safe, supplement the real comets digitally like the tv view of fireworks at the 2008 Olympics.

I don't want one that close; but if it was big enough and hit, we wouldn't be able to talk about it.

Orin

[orin stepanek]

http://query.nytimes.com/gst/fullpage.h ... A963948260

Art! Jules Verne was a great Science Fiction writer. My favorite was 20000 leagues under the sea. 8) I didn't recall 'Off On A Comet though. I think tearing of a chunk of Earth would probably put an end to life on Earth as we know it.

Orin

[neufer]

http://query.nytimes.com/gst/fullpage.h ... A963948260

Art! Jules Verne was a great Science Fiction writer. My favorite was 20000 leagues under the sea. 8)
I didn't recall 'Off On A Comet' though.
I think tearing of a chunk of Earth would probably put an end to life on Earth as we know it.

I remember reading 'Off On A Comet' while I was often "off on a comic" :


To avoid cometary deaths (both coming & going) Verne had to perform some "Avrà cadaveres."
_____________________________ { Avrà cadaveres: He will have cadavers (Italian) }

<<ABRACADABRA: The original Aramaic was עברא כדברא, AVRA KEDAVRA,
which means "what was said has come to pass" or "caused to perish like the word."

Over time, it was corrupted to its current pronunciation with the replacement of both "v" sounds with "b" sounds: b and v can be interchangeable in Aramaic. The word is now commonly used as an incantation by stage magicians and their imitators. In ancient times, however, it was taken much more seriously as an incantation to be used as a cure.>>

[DavidLeodis]

I would be grateful if someone could please clear up something that I'm unsure about in the picture.

In the description to the image that is brought up through the "the remarkable picture" link it seems to state that the dust tail is an antitail (the ion tail if it was present is said not to be visible in the picture). If it is an antitail, then is the dust tail that is usully seen in any picture of a comet always an antitail? The strange thing is I don't seem to recall much (if any) mention of antitails before Lulin.

Thanks.

[neufer]

I would be grateful if someone could please clear up something that I'm unsure about in the picture.

In the description to the image that is brought up through the "the remarkable picture" link it seems to state that the dust tail is an antitail (the ion tail if it was present is said not to be visible in the picture). If it is an antitail, then is the dust tail that is usually seen in any picture of a comet always an antitail? The strange thing is I don't seem to recall much (if any) mention of antitails before Lulin.

The ion tail always points away from the sun and
the dust tail usually also points away from the sun as viewed from earth.

However, here are some other APOD dust anti-tails:

http://antwrp.gsfc.nasa.gov/apod/ap040422.html
http://antwrp.gsfc.nasa.gov/apod/ap980220.html

[DavidLeodis]

Thanks neufer.

From those two APODs it would seem that the tail in the APOD of March 7 2009 is not an antitail that I thought it would likely be. I also learned from the APOD of April 22 2004 that it is known as "an anti-tail or anomalous tail". I now wonder what is the correct usage. Is it antitail or anti-tail.

[neufer]

From those two APODs it would seem that the tail in the APOD of March 7 2009 is not an antitail that I thought it would likely be. I also learned from the APOD of April 22 2004 that it is known as "an anti-tail or anomalous tail". I now wonder what is the correct usage. Is it antitail or anti-tail.

Probably antitail is more correct:
http://www.morewords.com/contains/anti/
http://wordnavigator.com/contains/anti/
However, anti-tail is probably somewhat clearer in meaning.

Perhaps, the more interesting question is whether it OK to call the
http://apod.nasa.gov/apod/ap090307.html antitail simply "a tail"
when there is no additional ion tail to confuse the issue in the first place?

[apodman]

Speaking strictly of the linguistic aspects of the question, the prefix "anti" falls under the same stylistic guidelines as the prefix "non". These prefixes are used without the hyphen when the word thus formed is easily readable; that is, when the reader automatically sees the prefix as a prefix. The hyphen is used when the word that would be formed without it is not automatically read as intended. Dictionaries disagree about exactly which words fall into which category, but I think "antitail" is a horrible looking word that would give pause to many readers, so I would go with the hyphenated version "anti-tail". Too many hyphens in general make a mess of text, but they should be used for clarity with "anti" and "non" whenever there is any doubt.

[DavidLeodis]

Thanks neufer and apodman.

Yes, "antitail" just does not seem right when reading it. I think anti-tail is better, though neither form really feels right.

[orin stepanek]

(The largest galaxies seen left of the comet's head or coma are cataloged as NGC 3016, NGC 3019, NGC 3020 and NGC 3024 and lie at a distance of 100 million light-years or so. When the exposures were made, on February 28, the comet was about 3.6 light-minutes from Earth. )

I'm seeing only 3 large galaxies left of the coma. What am I missing?

Orin

[bystander]

I'm seeing only 3 large galaxies left of the coma. What am I missing?

Blow it up! There's one in the middle of the three. I could only see it at max res.

[orin stepanek]

Thanks bystander! "I can see clearly now." I did blow it up before; but, I think I looked everywhere but in-between. I still had to take it to 125% after blowing it up to make sure. It's amazing how we can determine such far specks are large islands of millions of stars. 8) Sometimes I wish I were a young pup being around to see what technology man may have at his disposal years from now.

Orin