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  #2341 (permalink)  
Old 04-December-2006, 09:20 PM
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Quote:
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It's unlikely that you'll find two of these in the Southern hemisphere.
Well, Terror and Erebus the volcanos were named after ships.
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  #2342 (permalink)  
Old 04-December-2006, 09:46 PM
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Is this a colorful question? They're all white objects, under normal conditions.
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  #2343 (permalink)  
Old 04-December-2006, 09:51 PM
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Is this a colorful question? They're all white objects, under normal conditions.
George,

I'd disagree - two brown/black, one red and one steel grey...
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  #2344 (permalink)  
Old 04-December-2006, 10:01 PM
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The steel grey one participated in the Apollo programme...
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  #2345 (permalink)  
Old 05-December-2006, 12:14 AM
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Well, Terror and Erebus the volcanos were named after ships.
Ah, USS Arneb crossed the Antarctic Circle, as did Terror and Erebus of course. USS Crux I couldn't find much about, but considering its name...
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  #2346 (permalink)  
Old 05-December-2006, 12:25 AM
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There's even a USS Ozark. [Also a George, but no hhEb09'1, sorry]
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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.
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  #2347 (permalink)  
Old 05-December-2006, 12:38 AM
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Terror and Erebus were James Ross' ships on his Antarctic expedition in the 1840's. MAybe he was stargazing while crusing south?
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  #2348 (permalink)  
Old 05-December-2006, 01:55 AM
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Ah, USS Arneb crossed the Antarctic Circle, as did Terror and Erebus of course. USS Crux I couldn't find much about, but considering its name...
The USS Crux did spend some time in Brisbane, and New Guinea
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  #2349 (permalink)  
Old 05-December-2006, 06:04 AM
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Ah, USS Arneb crossed the Antarctic Circle, as did Terror and Erebus of course. USS Crux I couldn't find much about, but considering its name...

Very close and close enough given the discussion nature of the question.

Operation Deepfreeze I saw USS Arneb cross the Artic and Antarctic circles in the same year (first ship to do so). Her trip south stopped in New Zealand - red crux, and Franklin Island (antarctic). Terror and Erebus were the link to Franklin island.

Incidentally, and not intended, Terror, Erebus, Crux and Arneb are all Craters of sorts. Crater Cirque is part of th Arneb glacier formation, Erebus and Terror are both volcanic craters, Erebus is also the first crater for Opportunity on Mars and USS Crux is/was Crater class.
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Old 05-December-2006, 10:49 AM
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Are they the names of weather ships used by NOAA?

[Edit: Drat! Missed a page of posts!]
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Last edited by Eroica; 05-December-2006 at 03:13 PM.
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  #2351 (permalink)  
Old 05-December-2006, 12:19 PM
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Quote:
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Very close and close enough given the discussion nature of the question.
Interesting.

Give me a few to come up with something.
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  #2352 (permalink)  
Old 08-December-2006, 01:03 AM
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How far out is a lunar stationary orbit?

PS: Of course, the Earth is in lunar stationary orbit, but I mean, without regard to the Earth. OK, with and without. And earth/moon lagrange points too.

Last edited by hhEb09'1; 08-December-2006 at 02:48 AM.
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  #2353 (permalink)  
Old 08-December-2006, 04:30 PM
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How far out is a lunar stationary orbit?

PS: Of course, the Earth is in lunar stationary orbit, but I mean, without regard to the Earth. OK, with and without. And earth/moon lagrange points too.
Given that a seleno-stationary orbit (ignoring gravitational capture by the earth) would have a period of 27.32 days, around a tichy moon - the distance is going to be a long way!
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  #2354 (permalink)  
Old 08-December-2006, 05:32 PM
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- the distance is going to be a long way!
I"m going to need more precision that that

Make whatever assumptions you like.
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  #2355 (permalink)  
Old 08-December-2006, 06:49 PM
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Well my calc suggested something of the order of 86,900 km....
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  #2356 (permalink)  
Old 09-December-2006, 08:08 AM
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Quote:
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Well my calc suggested something of the order of 86,900 km....
I get 88459.303746763245858854948692471 km from the centre of the Moon!
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  #2357 (permalink)  
Old 09-December-2006, 04:28 PM
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Originally Posted by Eroica View Post
I get 88459.303746763245858854948692471 km from the centre of the Moon!
Question - did you use the sidereal or synodic period? The moon's rotation is once every 27.32 days. We could also disagree on the mass of the moon.
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  #2358 (permalink)  
Old 09-December-2006, 04:41 PM
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Quote:
Originally Posted by ozark1 View Post
Question - did you use the sidereal or synodic period? The moon's rotation is once every 27.32 days.
Sidereal, of course. but the figure I used was 2,360,586 seconds!

That may be 1 second too long. Wikipedia gives 23.321582 days, which is 2,360,584.6848 seconds.
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  #2359 (permalink)  
Old 09-December-2006, 05:11 PM
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My answer agrees with Eroica, down to the first place past the decimal (I went a little farther than that, but not two dozen places!). I used the wiki page for mass, and Eroica's derived period, and this wiki page for G.

Notice that that is farther than the Lagrange point, so the Lagrange point, unstable as it is, might make a better lunar stationary point.

Eroica's up.

PS: I just noticed that your discrepancy is just a bit more than the radius of the moon. Did you measure from the lunar surface, or the center as Eroica did?
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  #2360 (permalink)  
Old 11-December-2006, 08:15 AM
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While we're waiting for ozark1, here's my question:

What is the astronomical link between the following three characters in Greek mythology: Castor, Polydeuces and Phaethon?
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  #2361 (permalink)  
Old 11-December-2006, 05:44 PM
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Castor and Polydeuces are brothers, twins in fact. Phaethon is a comot whose dust causes the annual Geminid meteor shower happening as we speak.
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