[Fwd: A Whale of a Full Moon]
Hello Sunwatchers, The following link might be of interest to those who will turn to moon watchers these days. Günther Faltlhansl 48.1497° N 16.8803° E Received: by garius (mbox faltl) (with Cubic Circle's cucipop (v1.31 1998/05/13) Mon Dec 20 20:36:09 1999) X-From_: [EMAIL PROTECTED] Mon Dec 20 00:56:19 1999 Return-Path: [EMAIL PROTECTED] Received: from sslab.msfc.nasa.gov (sslab.msfc.nasa.gov [128.158.133.122]) by garius.magnet.at (8.9.3/8.9.3/magnet) with ESMTP id AAA12365; Mon, 20 Dec 1999 00:56:13 +0100 (MET) X-ListName: Science at Marshall Headline List [EMAIL PROTECTED] Received: by sslab.msfc.nasa.gov (MX V5.1-X An9n) id 2; Sun, 19 Dec 1999 17:06:41 -0600 Date: Sun, 19 Dec 1999 17:06:41 -0600 From: NASA Science News [EMAIL PROTECTED] Reply-To: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Message-ID: [EMAIL PROTECTED] Subject: A Whale of a Full Moon MIME-Version: 1.0 NASA Space Science News for Dec. 19, 1999 A Whale of a Full Moon: A bigger, brighter full moon will herald the beginning of northern winter on Dec. 22, 1999 as lunar perigee, the winter solstice, and the full moon all happen within a 10 hour period. FULL STORY at http://www.spacescience.com/newhome/headlines/ast19dec99_1.htm a href= http://www.spacescience.com/newhome/headlines/ast19dec99_1.htm link for AOL users/a You are subscribed to NASA's Space Science News mail server. This is a free service. To UNSUBSCRIBE, or CHANGE your address on this service, go to http://science.nasa.gov/news/subscribe.htm a href=http://science.nasa.gov/news/subscribe.htm; Link for AOL users/a. Linda Porter Code SD23 Science Systems Department NASA/Marshall Space Flight Center Huntsville AL 35812 [EMAIL PROTECTED] http://science.nasa.gov/
Re: passing time
Schist as well you explained this to us Tony ;-) For the puzzled: 'Schist'...A fine-grained metamorphic rock with component minerals arranged in layers'
Re: Solstice Perigee
I decided to get out xephem 3.0 and do some calculations for the upcoming solstice/lunar perigee/full moon. Times are Mountain Standard Time (UT - 7). According to the xephem's solver, here are the time and other values at the solstice (I found this by using the solver to minimize the solar declination): Limb Equ: Geo 2000.0 12/22/1999 0:26:37 MST: RA Dec EaDst Elong Phase RiseTm SetTm Sun 17:59:59.17 -23:26:21.5 0.9837 7:48 17:04 Moon 5:34:25.99 19:57:13.2 356675 173.1 100 17:28 7:33 Lunar perigee (found by minimizing lunar-earth distance): Limb Equ: Geo 2000.0 12/22/1999 3:54:08 MST: RA Dec EaDst Elong Phase RiseTm SetTm Sun 18:00:37.55 -23:26:21.2 0.9837 7:48 17:04 Moon 5:43:46.84 20:11:20.4 356654 174.9 100 17:28 7:33 Full moon (full moon calculation built in): Limb Equ: Geo 2000.0 12/22/1999 10:33:19 MST: RA Dec EaDst Elong Phase RiseTm SetTm Sun 18:01:51.38 -23:26:19.0 0.9836 7:48 17:04 Moon 6:01:49.93 20:33:15.8 356731 -177.1 100 17:28 7:33 Finally, here is the upcoming perihelion, almost twelve days later (found by minimizing the solar-earth distance): Limb Equ: Geo 2000.0 1/02/2000 23:35:12 MST: RA Dec EaDst Elong Phase RiseTm SetTm Sun 18:52:59.00 -22:52:49.6 0.9833 7:51 17:12 Moon 16:13:27.56 -16:35:37.9 405794 -37.9 11 4:07 14:40 I am not claiming high precision; I used default settings for comparison tolerances, etc. Jim 40N45, 111W53 --- -- | Jim Cobb | 540 Arapeen Dr. #100 | [EMAIL PROTECTED] | | Parametric| Salt Lake City, UT | (801)-588-4632 | | Technology Corp. | 84108-1202 | Fax (801)-588-4650 | --- -- Where there is a will, there is an Inheritance Tax.
FAQ website is up!!!
Hello all dialists: Yesterday afternoon I began to panic when I found out that I was unable to send you an attachment of the FAQs About Sundials by bulk e-mail. I think I heard that there are over 300 subscribers to the Sundial List, and I had visions of me trying to send individual e-mailings to each and every person. Dave Bell came to the rescue and offered to place the FAQs on his Sundial Image Archive website. I just checked and it's already up and running! Thank You Dave! (And thanks to Jeff Adkins for also offering his site). It's actually better than an attachment because it's more user friendly. Looking at how Dave has structured it, I think that it might serve well as the basis for the finished FAQ website. I encourage everyone to have a look at the new FAQ website (a work in progress) and to send me their comments following the instructions on the first page. I know that it is the holliday season and that you are all busy, so please take your time, there's no rush. website URL for Frequently Asked Questions About Sundials: http://dialist.webjump.com/ or http://www.crosswinds.net/~dialist/ Have a merry Christmas! John Carmichael 925 E. Foothills Dr. Tucson Az 85718 USA tel :520-696-1709 e-mail: [EMAIL PROTECTED]
Re: Solstice Perigee
[EMAIL PROTECTED] wrote: In regard to the excitement over the close perigee occuring when the earth is closest to the sun (very close to the December solstice.) My local paper made a comment that the Moon will appear 17% larger than a full moon last summer (that is in June-July for you down underlings), but the full moon in January will appear 40% larger. I suspect it was a misprint, but I thought I'd send it out so you could chew on it. ~troy Hello Troy, Well, let's find out. Full Moon June '99: 06/28 21:38 UTC Earth-Moon distance: 401955.3 km (249764.0 miles) True Equatorial RA: 18h 26m 34.5s Dec: -20°10'09 Topocentric coordinates: RA: 18h 26m 58.8s Dec: -20°25'17 Full Moon Dec.'99: 12/22 17:33 UTC Earth-Moon distance: 356733.3 km (221664.4 miles) True Equatorial RA: 06h 01m 47.3s Dec: +20°33'07 Topocentric coordinates: RA: 05h 59m 38.1s Dec: +19°45'39 The calculated ratio between the full moon distances above is 1.1267. However, to keep things straight note that the June '99 full moon is about three days after apogee and the Dec '99 full moon is very close to perigee, i.e., approx. 6hrs after. We'll see that this really doesn't matter much though and will keep things relative to the June '99 full moon. The intensity of light varies as the inverse square of the distance between a light source and the observer. Therefore, the intensity difference between these two distances is 1.2696 or approximately 27%. This is not trivial by any means. The trivial part is as follows. There has been some recent clamor about the claim of the Dec. 22 full moon not being the brightest full moon in 133yrs. Well, the fact is that those denying this are correct but what is the real magnitude of such a disclaimer? Well, let's take the same June '99 full moon distance, i.e., 401955.3 km and see what value we get when we divide it by the closest perigee in the years 1750 through 2125, which was 356375 km on January 4, 1912 and as it turns out was very close to being entirely full. So, 401955.3 km / 356375 km = 1.1279 and 1.1279^2 = 1.2722. Drum roll please, (1.2722/1.2696) * 100 = 0.2%. Is anyone impressed? A lot of disclaimer for 0.2%! The question of apparent size relates to the subtended angle of the moon at its various distances and is just the 2 * arc_sin(lunar radius / lunar distance). The lunar distances should be calculated as topocentric distances to be as accurate as possible. My suggestion, ENJOY IT! For a much more detailed treatment visit the following URL: http://www.fourmilab.ch/earthview/moon_ap_per.html Best, Luke
R: passing time
Frank Evans wrote : It's suggested by some in our newsgroup that time does not exist. In that case we sundialists are in the wrong business. Time does not exist, that's true, but sundialists have the great privilege of creating it Alberto Nicelli Italy (45* 28' N ; 7 52' E) -Messaggio originale- Da: Frank Evans [mailto:[EMAIL PROTECTED] Inviato: sabato 18 dicembre 1999 22.04 A: sundial@rrz.uni-koeln.de Oggetto: passing time Greetings, fellow dialists, It's suggested by some in our newsgroup that time does not exist. In that case we sundialists are in the wrong business. But there is a universal answer to this sort of nonsense, given, according to Boswell, by Dr. Johnson in reply to another nonsensical question. He said: I refute it thus. (Kicks a large stone.) Try it. Frank. 55N 1W -- Frank Evans
Re: Solstice Perigee
Thanks for the very detailed explaination Luke. So is the answer 27.2% brightness difference between the June Moon and the Dec. Moon? That would mean the paper was wrong. The newspaper also predicted the January Moon would be even brighter (something you didn't cover). Another thing that bothered me is after the astronomical explanation, they author of the article interviewed an astrologer, who basically told him the moon was in Cancer (it may have been another constellation for you sticklers), and the brightness didn't matter. Then he rambled off general predictions depending on your astrological sign. It's hard to believe we are about to enter the 2000s...Frankly, I'm disappointed. No flying cars, and astrologers are still taken seriously. ~Troy
Re: Graphic File Compression
From what I've read about graphics formats most prevalent on the Web (JPGs and GIFs), the general rule is: Use JPGs for color photographs, and use GIFs for simple graphics and line drawings. This is true. Also, I've heard that you must be careful about saving JPGs multiple times. Apparently, any graphics program such as Photoshop will compress the image each time it is saved. So, if you open, save, reopen, save, and so on, to a JPG, it will eventually have a rather noticeable degradation of quality. Of course, simply opening and closing without saving won't cause a loss of quality. ryan weh - Original Message - From: Tim Yu [EMAIL PROTECTED] To: sundial@rrz.uni-koeln.de Sent: Sunday, December 12, 1999 10:12 PM Subject: Re: Graphic File Compression [Roger Bailey] The ultimate solution was to download LView from the web http://www.lview.com and use it to save the bmp and tif files as JPEG files. The compression was over 30 times! Although JPEG is a lossey compression, the quality was indistinguishable for me from the originals. From what I've read about graphics formats most prevalent on the Web (JPGs and GIFs), the general rule is: Use JPGs for color photographs, and use GIFs for simple graphics and line drawings. Can I get added to your list Tony? Add me to the sub-list, too, please. Thanks. Tim Yu
