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Date: 14 May 2007 07:15:35
From: Bullseye
Subject: Jupiter and Saturn oppositions
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Do Jupiter and Saturn have such dramatic oppositions as Mars? If so
when is the best upcoming time to watch them?
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Date: 16 May 2007 03:24:53
From: oriel36
Subject: Re: Jupiter and Saturn oppositions
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On May 16, 6:42 am, David Nakamoto <david.nakam...@verizon.net > wrote:
> oriel36 wrote:
> > On May 14, 7:16 pm, David Nakamoto <david.nakam...@verizon.net> wrote:
> >> Bullseye wrote:
> >>> Do Jupiter and Saturn have such dramatic oppositions as Mars? If so
> >>> when is the best upcoming time to watch them?
> >> Don't know what you mean by dramatic? If you mean, "Does Jupiter or
> >> Saturn have as dramatic a size increase or brightness increase at
> >> opposition as Mars does?, the answer is no. Such things are determined
> >> by the relative distance differences when the planet is far away as
> >> opposed to when it's nearest to Earth.
>
> >> For Mars, this is considerable, because Mars' orbit is closer to Earth
> >> than either Jupiter or Saturn.
>
> > Very good,you are on the right track
>
> >> Jupiter and Saturn do look fainter and
> >> smaller when they're near the Sun as opposed to when they're at
> >> opposition, but the differences are minor compared to Mars.
>
> >> --- Dave
>
> > Then you jump the tracks and lapse into geocentricity in speaking of
> > Jupiter and Saturn being fainter in luminosity when 'near' the Sun.
>
> No, you misinterpreted my statements. We're amateur astronomers,
Everybody is an astronomer insofar as our existence depends on the
daily and annual cycles of the Earth, a really good astronomer knows
the details of those cycles and how our motions were discovered by
using the observed behavior in the motion of the other planets to
derive our orbital motion and planetary rotation to explain the daily
cycle.
>so
> most things are expressed as how they appear in the sky, as in "Near the
> Sun" meaning when either planet is visible in the sky NEAR THE SUN.
>
> --- Dave- Hide quoted text -
>
> - Show quoted text -
An astronomer looks into the solar system arena whereas astrologers
look up at the sky .You drop the idea of the planets being 'near the
sun' altogether and you start taking into account how the orbital
motion of the Earth sweeps around faster than Saturn and Jupiter in
that great celestial arena.
http://antwrp.gsfc.nasa.gov/apod/image/0112/JuSa2000_tezel.gif
Mr Tezel who supplied that time lapse footage of Jupiter and Saturn as
the faster Earth overtakes those outer planets has done more for
astronomy than anyone as far as I am concerned.The problem is that
there are no astronomers here to appreciate just how dramatic the work
of Copernicus actually is for I have yet to see one person affirm that
we know the Earth annual orbit is derived from orbital comparisons.
Misinterpretation !,I can tell you all about misinterpretation and the
catastrophic consequences of it but I choose to promote the correct
way of expressing the Copernican insights in an era that simply does
not care.
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Date: 15 May 2007 03:40:03
From: oriel36
Subject: Re: Jupiter and Saturn oppositions
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On May 14, 7:16 pm, David Nakamoto <david.nakam...@verizon.net > wrote:
> Bullseye wrote:
> > Do Jupiter and Saturn have such dramatic oppositions as Mars? If so
> > when is the best upcoming time to watch them?
>
> Don't know what you mean by dramatic? If you mean, "Does Jupiter or
> Saturn have as dramatic a size increase or brightness increase at
> opposition as Mars does?, the answer is no. Such things are determined
> by the relative distance differences when the planet is far away as
> opposed to when it's nearest to Earth.
>
> For Mars, this is considerable, because Mars' orbit is closer to Earth
> than either Jupiter or Saturn.
Very good,you are on the right track
> Jupiter and Saturn do look fainter and
> smaller when they're near the Sun as opposed to when they're at
> opposition, but the differences are minor compared to Mars.
>
> --- Dave
Then you jump the tracks and lapse into geocentricity in speaking of
Jupiter and Saturn being fainter in luminosity when 'near' the Sun.
http://antwrp.gsfc.nasa.gov/apod/image/0112/jupsatloop_tezel.jpg
I do not know what to think of you all.Jupiter and Saturn get
brighter as the Earth orbital motion approaches both planets and fade
as it overtakes them and the orbital distances widen.
The orbital orientation of Jupiter and Saturn as the Earth overtakes
them displays total solar radiation thereby increasing the observed
luminosity and as the Earth' distance widens and the orientations
between the Earth and the outer planets alter,the decrease in
luminosity is entirely expected.
http://www.universetoday.com/am/uploads/2005-0602jupiter-full.jpg
http://www.jb.man.ac.uk/public/Saturn-cassini.jpg
Considering that nobody here recognises the alteration in the Solar
radiation/Orbital shadow boundary ( SR/OS) of the Earth as the
background cause for global climate and hemispherical weather patterns
(seasons),even with images of the Earth from space,it is not suprising
that you drift from a reasonable heliocentric view to a geocentric
view in respect to Jupiter and Saturn.
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Date: 16 May 2007 05:42:19
From: David Nakamoto
Subject: Re: Jupiter and Saturn oppositions
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oriel36 wrote:
> On May 14, 7:16 pm, David Nakamoto <david.nakam...@verizon.net> wrote:
>> Bullseye wrote:
>>> Do Jupiter and Saturn have such dramatic oppositions as Mars? If so
>>> when is the best upcoming time to watch them?
>> Don't know what you mean by dramatic? If you mean, "Does Jupiter or
>> Saturn have as dramatic a size increase or brightness increase at
>> opposition as Mars does?, the answer is no. Such things are determined
>> by the relative distance differences when the planet is far away as
>> opposed to when it's nearest to Earth.
>>
>> For Mars, this is considerable, because Mars' orbit is closer to Earth
>> than either Jupiter or Saturn.
>
> Very good,you are on the right track
>
>
>> Jupiter and Saturn do look fainter and
>> smaller when they're near the Sun as opposed to when they're at
>> opposition, but the differences are minor compared to Mars.
>>
>> --- Dave
>
> Then you jump the tracks and lapse into geocentricity in speaking of
> Jupiter and Saturn being fainter in luminosity when 'near' the Sun.
No, you misinterpreted my statements. We're amateur astronomers, so
most things are expressed as how they appear in the sky, as in "Near the
Sun" meaning when either planet is visible in the sky NEAR THE SUN.
--- Dave
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Date: 14 May 2007 18:16:28
From: David Nakamoto
Subject: Re: Jupiter and Saturn oppositions
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Bullseye wrote:
> Do Jupiter and Saturn have such dramatic oppositions as Mars? If so
> when is the best upcoming time to watch them?
Don't know what you mean by dramatic? If you mean, "Does Jupiter or
Saturn have as dramatic a size increase or brightness increase at
opposition as Mars does?, the answer is no. Such things are determined
by the relative distance differences when the planet is far away as
opposed to when it's nearest to Earth.
For Mars, this is considerable, because Mars' orbit is closer to Earth
than either Jupiter or Saturn. Jupiter and Saturn do look fainter and
smaller when they're near the Sun as opposed to when they're at
opposition, but the differences are minor compared to Mars.
--- Dave
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Date: 14 May 2007 03:33:54
From:
Subject: Re: Jupiter and Saturn oppositions
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On May 14, 3:15 am, Bullseye <b...@ei.com > wrote:
> Do Jupiter and Saturn have such dramatic oppositions as Mars? If so
> when is the best upcoming time to watch them?
Since Jupiter reaches opposition roughly once per year, Mars roughly
every two years, and since Jupiter's detail is much easier to see, we
tend to take Jupiter for granted. OTOH, Mars is very small, compared
to Jupiter, and since the closer oppositions are rare opportunities to
see more detail than usual, we tend to plan for them.
When you look at Jupiter or Saturn you are looking at clouds, but when
you look at Mars, you are looking at the surface of the most Earth-
like planet in the solar system. It has polar caps, clouds and dust
storms. People used to imagine that intelligent life existed there.
Mars has some sort of mystique that Jupiter and Saturn lack.
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Date: 14 May 2007 03:30:48
From: oriel36
Subject: Re: Jupiter and Saturn oppositions
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On May 14, 8:15 am, Bullseye <b...@ei.com > wrote:
> Do Jupiter and Saturn have such dramatic oppositions as Mars? If so
> when is the best upcoming time to watch them?
http://antwrp.gsfc.nasa.gov/apod/image/0112/JuSa2000_tezel.gif
That is the Earth overtaking the closer Jupiter and the further away
Saturn in our common orbit around the central Sun.You know the Sun is
there as the orbital orientations of both Jupiter and Saturn display
the side facing solar radiation.
You should notice the variations in light intensity as the Earth
overtakes the planets and how it dims as the distance strecthes
between us an the outer planets due to the faster motion of the Earth.
You should notice that the stellar background is entirely irrelevent
to enjoying the spectacle of the motions of the planets around the Sun
and especially our own orbital motion which makes existence
possible,even for creatures who cannot get past 'conjunctions'.
You should also notice that the backward motion of the closer Jupiter
is far greater than the further away Saturn,this is best appreciated
from individual images of the plotted positions of Jupiter and Saturn
that goes into making the time lapse footage -
http://antwrp.gsfc.nasa.gov/apod/image/0112/jupsatloop_tezel.jpg
The great Copernican insights are within reach of intelligent people
who are not enamored with constellation astrology and magnification.So
much wonderful information can be extracted from the time lapse
footage above yet the members of this group belong to the dull and
dour Newtonian cult which does not recognise the correct way to
approach and resolve those images -
"For to the earth planetary motions appear sometimes direct,
sometimes stationary, nay, and sometimes retrograde. But from the sun
they are always seen direct.." Newton
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Date: 14 May 2007 00:51:42
From: Brian Tung
Subject: Re: Jupiter and Saturn oppositions
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Bullseye wrote:
> Do Jupiter and Saturn have such dramatic oppositions as Mars? If so
> when is the best upcoming time to watch them?
Those outer planets do not vary as dramatically as does Mars, because
Mars's orbit is much closer to ours, and as a result, its distance from
us changes much more between opposition and conjunction.
For instance, at a typical opposition, Mars gets as close as about 50
million miles (80 million km). Because Mars's orbit is noticeably
eccentric, however, that distance can shrink at favorable oppositions to
about 33 million miles (56 million km). At conjunction, on the other
hand, when Mars is just about as far as can be, it is about 235 million
miles (380 million km) away. That's a ratio of nearly 5 to 1 for an
ordinary opposition as compared to an ordinary conjunction; and almost
7 to 1 for an exceptional opposition.
Therefore, Mars, which appears just about 4 arcseconds across (the width
of a ping-pong ball as seen from 20 km away) at conjunction, got as big
as 28 arcseconds or so in 2003. At that size, even 150x can reveal
quite a bit of detail, but at 4 arcseconds (and with Mars close to the
Sun when near conjunction), precious little can be seen, even when it is
safe to observe.
By comparison, Jupiter and Saturn, being much further away at all times,
vary much less in distance and appearance. Jupiter varies its distance,
and therefore its apparent diameter, by a ratio of about 3 to 2 over the
course of a year; Saturn, even less, a ratio of about 6 to 5. Mostly,
you can observe these planets year-round, except for a couple of months
around conjunction, although you might need to get up in the morning for
some of the year.
A somewhat more subtle effect is that Mars shows some phases--not the
full complement that Venus does, since we can never get "outside" Mars
in its orbit. Still, Mars in its least illuminated phase shows about a
two-thirds disc. Jupiter, on the other hand, never shows less than
about a 99-percent illuminated disc, while Saturn is essentially always
fully illuminated. Both of these outer planets show, at most, a subtle
softening of the edge (called the "limb") on one side--where the night
side of the planet is just peeking over. Of course, Saturn also has its
magnificent rings.
One further, psychological reason that Mars oppositions are so dramatic
is that it has so much to offer at good oppositions, and so we feel the
impact of those oppositions all the more.
--
Brian Tung <brian@isi.edu >
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.html
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Date: 15 May 2007 00:55:32
From: Thomas Womack
Subject: Re: Jupiter and Saturn oppositions
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In article <f294ee$gpb$1@praesepe.isi.edu >, Brian Tung <brian@isi.edu> wrote:
>Jupiter, on the other hand, never shows less than
>about a 99-percent illuminated disc, while Saturn is essentially always
>fully illuminated.
I seem to recall some kind of inordinate brightening of Saturn's rings
visible from Earth when the geometry is absolutely straight on (IE
when Earth is transiting the Sun as seen from Saturn)
Ah yes,
http://www.mmedia.is/bjj/3dtest/saturn/index.html
http://www.planetary.org/blog/article/00000242/
Those are very rare events (the next one is 2049), but extremely
striking. Apparently Enceladus also brightens enormously.
Tom
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Date: 14 May 2007 10:11:15
From: Bullseye
Subject: Re: Jupiter and Saturn oppositions
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I see. When will Saturn's rings be at a good viewing angle again?
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Date: 14 May 2007 11:55:48
From: Esmail Bonakdarian
Subject: Re: Jupiter and Saturn oppositions
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Bullseye wrote:
> I see. When will Saturn's rings be at a good viewing angle again?
Actually, they still look pretty amazing .. Saturn never fails to please :-)
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Date: 14 May 2007 19:34:29
From: Trane Francks
Subject: Re: Jupiter and Saturn oppositions
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On 2007-05-14 19:11 +0900, Bullseye wrote:
> I see. When will Saturn's rings be at a good viewing angle again?
Ring plane crossings happen approximately every 13-15 years. The last
"minimum" was in 1995. The next one will be in 2009. That should give
you a good idea of what to expect.
Cheers,
trane
--
/////////////////////////////////////////////////////////
// Trane Francks trane@gol.com Tokyo, Japan
// Practice random kindness and senseless acts of beauty.
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Date: 14 May 2007 00:53:40
From: Brian Tung
Subject: Re: Jupiter and Saturn oppositions
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I (Brian Tung) wrote:
> Therefore, Mars, which appears just about 4 arcseconds across (the width
> of a ping-pong ball as seen from 20 km away) at conjunction...
Oops--that should be "as seen from 2 km away." Still tiny, but not as
tiny as I said.
--
Brian Tung <brian@isi.edu >
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.html
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Date: 14 May 2007 00:39:20
From: Ben
Subject: Re: Jupiter and Saturn oppositions
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On May 14, 2:15 am, Bullseye <b...@ei.com > wrote:
> Do Jupiter and Saturn have such dramatic oppositions as Mars? If so
> when is the best upcoming time to watch them?
I don't know if I would call them "dramatic". They do get
bright but there's not a whole lot of fanfare associated with
them.
Saturn was at opposition on Feb 10. Its sliding into the
twilight now and shrinking. Also the rings are beginning
to flatten.
Jupiter will be at opposition on 5 June @ 23:08 UT.
Currently it's -2.54 mag and showing a disk nearly
45" diameter. It will get brighter and larger.
Ben
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