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Is this right?



 
 
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Old July 14th 05, 05:40 PM
TeaTime
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"Dr John Stockton" wrote in message
...
JRS: In article , dated
Sun, 10 Jul 2005 06:29:05, seen in news:uk.sci.astronomy, Simon Coombs
posted :
The way I view this is that distances between all the planets in our solar
system and earth are continuously varying and some planets have eliptical
orbits too so any statement of distance has to be for a given date.


"Steve" wrote in message
...
Quote from Sky&Telescope website:

"Mercury is about 8 light-minutes distant, Venus is about 12
light-minutes
away, and Saturn is 85 light-minutes from us. Jupiter is 45
light-minutes
distant."

Surely that can't be correct about Venus?
Light from Venus should reach us before light from Mercury?


Please put responses after trimmed quotes, as per newsgroup FAQ and UK.*
and Usenet norms.

No doubt Sky and Telescope, in choosing the word "is", were referring to
the (then-) present time. Such Web pages can, easily enough, be
regularly updated, either by software or by staff. The time in minutes
from Mercury, at least, should have changed by now or will soon do.

All planets have elliptical orbits (none ate truly circular; and a
circle is just a limiting case of an ellipse anyway), neglecting very
small effects of moons, other planets, relativity, etc.

At present, Mercury must be somewhere near maximum elongation, being
visible, and so at around 90 deg to Earth; and Venus, being near it
visually, must be at about 45 deg to Mercury. Evidently Venus is in the
more distant (from us) part of its orbit. The figures given are
compatible with that.

Doubtless there are Web sites showing the present Solar System as seen
from above (do Australian sites show a mirror-image?).

--
© John Stockton, Surrey, UK. Turnpike v4.00
MIME. ©
Web URL:http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms &
links;
Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm,
etc.
No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail
News.


Here we can see the current displacement of the planets close enough for
discussion:
http://www.fourmilab.ch/cgi-bin/uncgi/Solar
Mercury is approaching its closest point relative to us.. Mars is heading
for closest around Halloween... Venus is about 100 degrees away from Mars
at this time..

Who cares what the Australian web sites show... they can't even call Marmite
by its proper name..

That's enough elipses and elipsis for one night.

getting near TeaTime


 




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