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Old 2008-04-18, 07:09   #1
9021951
 
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Thumbs up Something wondrous and rare to see . . .

I just want to share with those of you who enjoy marveling at our neck of the Galactic woods, especially the Solar System:

Yes, that is Luna peering at the GOES West satellite ( 75 degrees west ) from somewhere probably high over eastern Europe.

There is an IR pix too which I may post at my own site:

http://www.nicolavalley.org/moonpix

shortly ( please wait patiently if it's not there yet. )

Does anyone know the mathematics involved in predicting these events?

Simon
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Old 2008-04-18, 08:26   #2
xilman
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Quote:
Originally Posted by 9021951 View Post
I just want to share with those of you who enjoy marveling at our neck of the Galactic woods, especially the Solar System:

Yes, that is Luna peering at the GOES West satellite ( 75 degrees west ) from somewhere probably high over eastern Europe.
Nice one indeed.

Good example, too, of atmospheric refraction.


Paul
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Old 2008-04-19, 01:40   #3
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Quote:
Originally Posted by 9021951 View Post
Yes, that is Luna peering at the GOES West satellite ( 75 degrees west ) from somewhere probably high over eastern Europe.
When you take into account that Luna is ten times as far beyond Earth on the other side as GOES is from Earth on its side, the sublunar point is far east of Europe -- my first guess would be East Asia or south of there.

Then, estimate the angular width of Earth as seen from GOES. Geosynch orbit = 22200 miles above surface, Earth radius = 4000 miles. Earth limb is 4000 miles from center at (approx) right angle to GOES-center line. So angle at GOES from Earth center to Luna is about (4000 / (22200+ 4000)) radians = about 9 degrees. The corresponding angle at Earth's center would a bit more, say 10 degrees.

So Luna is only 10 degrees away from being above the Earth longitude directly opposite GOES, 105 degrees east. Luna subpoint is roughly 95 degrees east, Burma's longitude.

Quote:
Does anyone know the mathematics involved in predicting these events?
Some planetarium/star-charting software may have the ability to find alignments as seen from a satellite, or at least from some longitude at geosynchronous orbit.

Last fiddled with by cheesehead on 2008-04-19 at 01:49
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Old 2008-04-20, 09:47   #4
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Hey, cheesehead, you more or less nailed where the moon would be seen at transit time.

I have it placed at 97 degrees east, near a town or city named Kyaikto, Burma.

If you were on a boat at sea on the Earth's equator, the Moon would be about 7 degrees north of the zenith, about 100 to 200 km west of the Batu Islands off Sumatra.

I have usually used Dance of the Planets, but need to do some interpolating.

The rarity of these events on GOES satellites is the rigidity of the imaging schedule for
full disk pix, and that of presentation at some websites on the Internet. If you had a GOES receiver, most images would be full disk. The fact though that most of these images are on the hour, or half hour, still complicates the process.

All of the images from Asia were via the GMS 5 satellite of Japan, which is now defunct, and has been replaced by GMS 6, but still located at 140 degrees east if I am remembering correctly.

I have posted a lot more images from 2001 January and February; one or two leave one thinking that the Earth has a zit, being so close to the Earth's limb.

Simon

Last fiddled with by 9021951 on 2008-04-20 at 09:51 Reason: tidying some typing and grammar
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