Jupiter's brightness?
Will Janoschka
Jupiter will be quite close to earth tomorrow, but why is it
brighter?
I assume by brightness they mean the solar reflection
from each unit area of Jupiter. Does Jupiter have some
spectular reflection properties? -will-
Androcles
"Will Janoschka" <wil...@nospam.pobox.com> wrote in message
news:DmJ5SKFdRQph-p...@209-142-179-227.dyn.centurytel.net...
Sam Wormley
> The news folk say that Jupiter is brighter than ever!
> Jupiter will be quite close to earth tomorrow, but why is it
> brighter?
Newton's Inverse square law... Jupiter is not only closer to
the Earth, but also the Sun.
http://en.wikipedia.org/wiki/Inverse-square_law
> I assume by brightness they mean the solar reflection
> from each unit area of Jupiter. Does Jupiter have some
> spectular reflection properties? -will-
Jupiter is so far away that is acts like a specular light
source.
Will Janoschka
Hi Sam,
I did not know that Jupiter is approching the Sun also.
Please help me out with the distinction 'tween specular and
diffuse reflection. thanks -wll-
Sam Wormley
All the planets are in elliptical orbits about the sun. Jupiter's
eccentricity is 0.048 compared to 0.017 for the Earth.
The reflection from Jupiter would not be considered specular, but
Jupiter as an almost point source (specular) from the perspective
of the Earth.
hanson
"Sam Wormley" <swor...@gmail.com> wrote in message
eccentricity is 0.048 compared to 0.017 for the Earth.
>
Why are the elliptical orbits of the planets in
our solar system so close to being circular?
Why is that?
hanson
Yousuf Khan
From what we're learning about other solar systems, ours is indeed an
unusually idyllic place. All of the major planets are in very stable
nearly circular orbits, with very little eccentricity. Shouldn't be
surprising, that's probably why we're even living here.
It's been suggested that our giant planets migrated outwards from the
Sun, whereas in a lot of other solar systems we're finding they migrated
inwards. The further location our giant planets has cleared out some
stable, circular lanes for our terrestrial planets. If our giants had
migrated inwards, then there would be no room for terrestrials in the
inner part of the solar system.
There was a story today that says that Uranus was tossed around like a
pinball by Jupiter and Saturn, which pushed not only Uranus to migrate
outwards (and to tilt on its side like no other planet we know), but
also caused Jupiter and Saturn to migrate outwards too.
Yousuf Khan
Will Janoschka
Thank you again,
I am concerned more about brightness vs. illumination.
I see brightness as a new dimension to spacetime
because it has all the three spatial dimesions and time
normalized, but yet it has its own measurements.
Where is Uncle Al!. I hope I am not an idiot.
-wiil-
dlzc
On Sep 19, 10:21 pm, "hanson" <han...@quick.net> wrote:
> "Sam Wormley" <sworml...@gmail.com> wrote in message
Let's look at the Earth-Moon system. The Earth is able to tidally
boost the Moon, transferring angular momentum from the Earth to the
Moon. An elliptical orbit (in some sense) is an orbit of a body that
does not have enough energy to orbit circularly at the maximum
radius. And as the body gets closer, rotational momentum transfer is
increased. So in some time, elliptical orbits will be circularized by
tidal effect, if the central body is spinning.
What gets me is that Mercury has nearly the highest orbital
eccentricity in the system:
http://nssdc.gsfc.nasa.gov/planetary/factsheet/planet_table_british.html
(and Neptune's is so low to be so far from the Sun...)
David A. Smith
hanson
> All the planets are in elliptical orbits about the sun. Jupiter's
> eccentricity is 0.048 compared to 0.017 for the Earth.
>>
> Why are the elliptical orbits of the planets in
> our solar system so close to being circular?
> Why is that?
> hanson
>
>
"Yousuf Khan" <bbb...@spammenot.yahoo.com> wrote:
... our giant planets migrated outwards from the Sun, ...
... Uranus was tossed around by Jupiter and Saturn,... &
Uranus to migrate outwards...
>
David A. Smith "dlzc" <dl...@cox.net> wrote:
The Earth tidally .. transfersangular momentum to the Moon.
An elliptical orbit ... does not have enough energy to orbit
circularly at the maximum radius. As the body gets closer,
rotational momentum transfer is increased. In time, elliptical
spinning.
>
Cool. Thanks. Both of you imply the cause to be simple orbital
mechanics coupled with tidal effects, TE, which cause sloshing
of liquids envelopes and density variations of gaseous bodies,
or compression heating of solid planets.
>
Now how much of the TE energy goes into planetary distortions
and how much goes into orbital changes. Any equation/s?
>
There ought to be an equation/s that show orbital time drifts
from elliptic towards circular orbits. IOW, an equation/s that
indicate an energy minimum when orbits becomes asymptotically
circular... or....
Are planetary systems more chaotic then classical or even
relativistic mechanics describe them to be? Any equation/s?
OG
"Will Janoschka" <wil...@nospam.pobox.com> wrote in message
news:DmJ5SKFdRQph-p...@209-142-179-227.dyn.centurytel.net...
Specular reflection is not particularly significant.
Jupiter is at its brightest now because of two combined effects.
The distance between Jupiter and the Sun which determines the amount of
light incident on the surface of the planet
The distance between Jupiter and the Earth which determines the angular size
of the planet and hence the brightness of the planet as seen by us.
With regard to the first factor, Jupiter has an orbit of almost 12 years and
will be closest to the sun around mid March 2011, when it will be almost 6%
closer to the sun than average, hence receiving about 12% more surface
illumination than average.
With regard to the second factor, the Earth's own orbit takes it nearer and
further from Jupiter with a period of just under 400 days. The time when the
Earth and Jupiter are closest is called the conjunction (when they are
furthest is called opposition), and the angular size of the planet from
Earth is greatest at this time. This year's conjunction happens to be the
best one of the current cycle of Jupiter's orbit, both in terms of the
Jupiter - Sun distance (brightest surface) and the Jupiter - Earth distance
(angular size).
There is a useful resource here that allows you to generate tables related
to Jupiter's orbit.
http://pds-rings.seti.org/tools/ephem2_jup.html
dlzc
On Sep 20, 11:20 am, "hanson" <han...@quick.net> wrote:
> > "Sam Wormley" <sworml...@gmail.com> wrote in message
> > All the planets are in elliptical orbits about the sun. Jupiter's
> > eccentricity is 0.048 compared to 0.017 for the Earth.
>
> "hanson" <han...@quick.net> wrote:
> > Why are the elliptical orbits of the planets in
> > our solar system so close to being circular?
> > Why is that?
> > hanson
>
> If I read you guys right... in essence you said...
>
> "Yousuf Khan" <bbb...@spammenot.yahoo.com> wrote:
>
> ... our giant planets migrated outwards from the Sun, ...
> ... Uranus was tossed around by Jupiter and Saturn,... &
> Uranus to migrate outwards...
>
> David A. Smith "dlzc" <dl...@cox.net> wrote:
> The Earth tidally .. transfers angular momentum to
> the Moon. An elliptical orbit ... does not have enough
> energy to orbit circularly at the maximum radius. As
> the body gets closer, rotational momentum transfer is
> increased. In time, elliptical orbits will be circularized
> by tidal effect, if the central body is spinning.
>
> hanson wrote:
>
> Cool. Thanks. Both of you imply the cause to be
> simple orbital mechanics coupled with tidal effects, TE,
> which cause sloshing of liquids envelopes and density
> variations of gaseous bodies, or compression heating
> of solid planets.
>
> Now how much of the TE energy goes into planetary
> distortions and how much goes into orbital changes. Any
> equation/s?
Well, conservation of angular momentum will be one of the set that
needs to be satisfied.
This reference:
http://books.google.co.uk/books?id=smAEGoPNThMC&pg=PA275&lpg=PA275&dq=earth+radioactive+heating+W&source=bl&ots=PEG7WwXi0R&sig=9l93rfNA1CRZMWZ5PCfruMG1D0o&hl=en&ei=Qx-1SpjEENmf4gbF85B9&sa=X&oi=book_result&ct=result&resnum=4#v=onepage&q&f=false
... (on another page that the one linked to) may talk about 3.75 TW of
tidal heating, whether due to lunar or lunar plus solar, I don't know.
> There ought to be an equation/s that show orbital
> time drifts from elliptic towards circular orbits. IOW, an equation/s that
> indicate an energy minimum when orbits becomes asymptotically
> circular... or....
> Are planetary systems more chaotic then classical or even
> relativistic mechanics describe them to be? Any equation/s?
Not finding any easily.
http://en.wikipedia.org/wiki/Bi-elliptic_transfer
Interesting sidelight though...
http://www.sciencedaily.com/releases/2005/05/050510185421.htm
David A. Smith
hanson
"dlzc" <dl...@cox.net> wrote in message
news:4c854f8d-9514-4534...@m17g2000prl.googlegroups.com...
Dear hanson:
David A. Smith wrote:
> Well, conservation of angular momentum will be one of
> the set that needs to be satisfied.
> This reference:
> <<http://tinyurl.com/Smitty-Tidal-heating>>
>... (on another page that the one linked to) may talk about 3.75 TW of
> tidal heating, whether due to lunar or lunar plus solar, I don't know.
>
Prior to that hanson wrote:
> There ought to be an equation/s that show orbital
> time drifts from elliptic towards circular orbits. IOW, an equation/s that
> indicate an energy minimum when orbits becomes asymptotically
> circular... or....
> Are planetary systems more chaotic then classical or even
> relativistic mechanics describe them to be? Any equation/s?
>
David A. Smith wrote:
Not finding any easily. Interesting sidelight though...
http://www.sciencedaily.com/releases/2005/05/050510185421.htm
>
Not finding any [equations] easily, BUT.
http://en.wikipedia.org/wiki/Bi-elliptic_transfer
>
hanson wrote:
Your last link makes ref to the
http://en.wikipedia.org/wiki/Oberth_effect
which, in a quick glance, contains simple equations that
could perhaps be applied to get estimates/solutions to
the issues I raised. I'll look into it.
Thanks, Smitty. You are a good man.
hanson
Darwin123
On Sep 19, 9:30 pm, wil...@nospam.pobox.com (Will Janoschka) wrote:
> The news folk say that Jupiter is brighter than ever!
> I assume by brightness they mean the solar reflection
> from each unit area of Jupiter. Does Jupiter have some
> spectular reflection properties? -will-
Jupiter does not have an exposed surface. Most of the
reflection has to come from elastic scattering from gas molecules and
aerosol particles. Hence, it doesn't have specular reflection.
Specular reflection has to obey the law of reflection (angle of
incidence=angle of incidence). Specular reflection is only well
defined when there is a well defined and "smooth surface". Many of the
particles in Jupiter's atmosphere will be large and irregularly
shaped. Even the liquid droplets, if there are any, will vary in
diameter and composition. Thus, the light of the sun reflected from
Jupiters surface will be randomized.
Most of the light from Jupiter would be better described as
diffuse reflection, rather than specular reflection. The light from
any point of Jupiter is scattered in all directions, at least on a
macroscopic level.
The ideal surface for diffuse reflection is called a Lambertian
surface. I don't know how closely the atmosphere of Jupiter comes to
being a Lambertian surface. However, it must come close. If the
reflection of sunlight from Jupiter was specular, then we would see an
image of the sun reflected from Jupiter. The features of Jupiter's
atmosphere could not be seen if the the reflection was specular.
Because the reflection of sunlight from Jupiter is diffuse, no image
of the sun can be seen on Jupiter. Features of Jupiter's atmosphere
are seen in the image, but not an image of the sun.
The terms "specular reflection" and "diffuse reflection" are
phenomenological terms describing the extent to which a surface
"randomizes" the phase change of the light being reflected. If light
at a particular frequency undergoes a random phase change upon being
reflected, the reflection is called diffuse. If light at a particular
frequency undergoes a fixed phase change upon being reflected, the
reflection is called specular.
Look at a mirror. You see your own image. This is specular
reflection. Look at a painted wall. You only see the wall. This is a
diffuse reflection.
Inverse square always applies to diffuse reflected light. A
collimated light beam that is diffusely reflected becomes a spreading
hemisphere. However, inverse square law doesn't always apply to
specular reflected light. A collimated light beam that is specularly
reflected is still collimated.
Since Jupiter reflects in a diffuse manner, inverse square law
always applies. The closer Jupiter is to the earth, the brighter it
will appear. There is also an issue of how closely it comes to the
sun. However, this is less important in the problem.
dlzc
On Sep 20, 2:09 pm, "hanson" <han...@quick.net> wrote:
...
> Thanks, Smitty. You are a good man.
Takes one to know one. "Good" does not require "easy to get along
with"...
Hang 'em high. If you figure anything interesting, might let us know.
David A. Smith
Will Janoschka
>
> "Will Janoschka" <wil...@nospam.pobox.com> wrote in message
> news:DmJ5SKFdRQph-p...@209-142-179-227.dyn.centurytel.net...
> > The news folk say that Jupiter is brighter than ever!
> > Jupiter will be quite close to earth tomorrow, but why is it
> > brighter?
> > I assume by brightness they mean the solar reflection
> > from each unit area of Jupiter. Does Jupiter have some
> > spectular reflection properties? -will-
>
> Specular reflection is not particularly significant.
> Jupiter is at its brightest now because of two combined effects.
>
> The distance between Jupiter and the Sun which determines the amount of
> light incident on the surface of the planet.
Yes, I agree. that would increase the brightness of the reflected
light from Jupiter.
that does not increase the brightness of the Sun as observed from
Jupiter.
> The distance between Jupiter and the Earth which determines the angular size
> of the planet and hence the brightness of the planet as seen by us.
That would increase the amount of sunlight incident on the surface of
the Earth that
is reflected by Jupiter but that does not increase the brightness of
Jupiter as seen
from earth. The units of brightness normalize out solid angle.
The news folk say that Jupiter will be brightest at midnight local
time.
If true that would indicate significant spectular reflection from
Jupiter.
At midnight the sun is behind the earth kinda.
Perhaps I am confused about the folks use of "brightest"
They seem to use brightest as max illumination, rather than
max brightness.
>
> With regard to the first factor, Jupiter has an orbit of almost 12 years and
> will be closest to the sun around mid March 2011, when it will be almost 6%
> closer to the sun than average, hence receiving about 12% more surface
> illumination than average.
Does that mean that Jupiter will have max brightness March 2011 as
seen
from anywhere except on the side away from the Sun?
>
> With regard to the second factor, the Earth's own orbit takes it nearer and
> further from Jupiter with a period of just under 400 days. The time when the
> Earth and Jupiter are closest is called the conjunction (when they are
> furthest is called opposition), and the angular size of the planet from
> Earth is greatest at this time. This year's conjunction happens to be the
> best one of the current cycle of Jupiter's orbit, both in terms of the
> Jupiter - Sun distance (brightest surface) and the Jupiter - Earth distance
> (angular size).
>
> There is a useful resource here that allows you to generate tables related
> to Jupiter's orbit.
> http://pds-rings.seti.org/tools/ephem2_jup.html
>
>
Thank you.
OG
"Will Janoschka" <wil...@nospam.pobox.com> wrote in message
news:DmJ5SKFdRQph-p...@209-142-179-253.dyn.centurytel.net...
> On Mon, 20 Sep 2010 19:33:12, "OG" <ow...@gwynnefamily.org.uk> wrote:
>
>>
>> "Will Janoschka" <wil...@nospam.pobox.com> wrote in message
>> news:DmJ5SKFdRQph-p...@209-142-179-227.dyn.centurytel.net...
>> > The news folk say that Jupiter is brighter than ever!
>> > Jupiter will be quite close to earth tomorrow, but why is it
>> > brighter?
>> > I assume by brightness they mean the solar reflection
>> > from each unit area of Jupiter. Does Jupiter have some
>> > spectular reflection properties? -will-
>>
>> Specular reflection is not particularly significant.
>> Jupiter is at its brightest now because of two combined effects.
>>
>> The distance between Jupiter and the Sun which determines the amount of
>> light incident on the surface of the planet.
>
> Yes, I agree. that would increase the brightness of the reflected
> light from Jupiter.
> that does not increase the brightness of the Sun as observed from
> Jupiter.
Why not? If you're 6% closer, you'll be 12% brighter.
>> The distance between Jupiter and the Earth which determines the angular
>> size
>> of the planet and hence the brightness of the planet as seen by us.
>
> That would increase the amount of sunlight incident on the surface of
> the Earth that
> is reflected by Jupiter but that does not increase the brightness of
> Jupiter as seen
> from earth. The units of brightness normalize out solid angle.
What units of brightness are you using?
> The news folk say that Jupiter will be brightest at midnight local
> time.
> If true that would indicate significant spectular reflection from
> Jupiter.
> At midnight the sun is behind the earth kinda.
Jupiter will be brightest at midnight local time because the sky will be
darkest at midnight and will be at its highest altitude (so minimising the
dimming due to the atmosphere).
Nothing to do with specular reflection.
> Perhaps I am confused about the folks use of "brightest"
> They seem to use brightest as max illumination, rather than
> max brightness.
>>
>> With regard to the first factor, Jupiter has an orbit of almost 12 years
>> and
>> will be closest to the sun around mid March 2011, when it will be almost
>> 6%
>> closer to the sun than average, hence receiving about 12% more surface
>> illumination than average.
>
> Does that mean that Jupiter will have max brightness March 2011 as
> seen
> from anywhere except on the side away from the Sun?
By March 2011, the Earth will be at the other side of the Sun in our orbit ,
so Jupiter won't be visible at all at night. Of course, by then it will be
almost 300,000,000 km further away from us than at present, so even if it
were visible, its angular size (and brightness) would be much less.
>> With regard to the second factor, the Earth's own orbit takes it nearer
>> and
>> further from Jupiter with a period of just under 400 days. The time when
>> the
>> Earth and Jupiter are closest is called the conjunction (when they are
>> furthest is called opposition), and the angular size of the planet from
>> Earth is greatest at this time. This year's conjunction happens to be the
>> best one of the current cycle of Jupiter's orbit, both in terms of the
>> Jupiter - Sun distance (brightest surface) and the Jupiter - Earth
>> distance
>> (angular size).
NB - an apology is due here - I got the terms the wrong way around, Jupiter
is currently in *opposition* not conjunction, as this is defined to be when
the Sun and a planet are on opposite sides of the Earth - i.e. the planet is
due south at midnight.
*Conjunction* is when the planet is on the same side of the Earth as the Sun
, and that's where it'll be next year (on 5th- 6th April it'll cross the
centre line of the sun).
Will Janoschka
>
>
> "Will Janoschka" <wil...@nospam.pobox.com> wrote in message
> news:DmJ5SKFdRQph-p...@209-142-179-253.dyn.centurytel.net...
> > On Mon, 20 Sep 2010 19:33:12, "OG" <ow...@gwynnefamily.org.uk> wrote:
> >
> >>
> >> "Will Janoschka" <wil...@nospam.pobox.com> wrote in message
> >> news:DmJ5SKFdRQph-p...@209-142-179-227.dyn.centurytel.net...
> >> > The news folk say that Jupiter is brighter than ever!
> >> > Jupiter will be quite close to earth tomorrow, but why is it
> >> > brighter?
> >> > I assume by brightness they mean the solar reflection
> >> > from each unit area of Jupiter. Does Jupiter have some
> >> > spectular reflection properties? -will-
> >>
> >> Specular reflection is not particularly significant.
> >> Jupiter is at its brightest now because of two combined effects.
> >>
> >> The distance between Jupiter and the Sun which determines the amount of
> >> light incident on the surface of the planet.
> >
> > Yes, I agree. that would increase the brightness of the reflected
> > light from Jupiter.
> > that does not increase the brightness of the Sun as observed from
> > Jupiter.
>
> Why not? If you're 6% closer, you'll be 12% brighter.
You are correct, I am pre 1996.
>
> >> The distance between Jupiter and the Earth which determines the angular
> >> size
> >> of the planet and hence the brightness of the planet as seen by us.
> >
> > That would increase the amount of sunlight incident on the surface of
> > the Earth that
> > is reflected by Jupiter but that does not increase the brightness of
> > Jupiter as seen
> > from earth. The units of brightness normalize out solid angle.
>
> What units of brightness are you using?
Same as radiance W / ( m * m * sr). The one that has all three
distances normalized out. Radiance is normal to the other three.
dimensions. If you replace power with energy you have time
normalized
out also, but that (has no name). (has no name) is normal to
spacetime.
my apology is also due. I'm old and never read FS-1037c.
Sorry for wasting your time. Thank you, I will avoid using
brightness for a measurment, in the future.
Bob
|>
|>What gets me is that Mercury has nearly the highest orbital
|>eccentricity in the system:
|>http://nssdc.gsfc.nasa.gov/planetary/factsheet/planet_table_british.html
|>(and Neptune's is so low to be so far from the Sun...)
Nothing on Nibiru (planet X), the Red planet the size of Jupiter
with a 4,000yr orbit....yeah I know, "it doesn't exist"...sure.
40 years ago, I couldn't find more than about 20 moons around
Jupiter, now there are 63.....for every 2,000 year period about.
The GUK Sun is not recognized in a lot of discussions, because they
want anonymity from the powers that be,....it seems to be working...!
I know, I know, "not one of these again".....>:)......hava a nice
ghibly day.
Bob
Andrew Usher
> What gets me is that Mercury has nearly the highest orbital
> eccentricity in the system:
> http://nssdc.gsfc.nasa.gov/planetary/factsheet/planet_table_british.html
> (and Neptune's is so low to be so far from the Sun...)
Could this have anything to do with Mercury's 3:2 rotational
resonance?
Andrew Usher
Yousuf Khan
> Nothing on Nibiru (planet X), the Red planet the size of Jupiter
> with a 4,000yr orbit....yeah I know, "it doesn't exist"...sure.
NASA has put up the WISE infrared telescope. It should be able to detect
any sort of unknown planet or brown dwarf or whatever. So far it hasn't.
Yousuf Khan
Yousuf Khan
I think it has more to do with General Relativity. The Mercury Anomaly
was as a result of relativistic considerations.
Yousuf Khan
Andrew Usher
> >> What gets me is that Mercury has nearly the highest orbital
> >> eccentricity in the system:
> >> http://nssdc.gsfc.nasa.gov/planetary/factsheet/planet_table_british.html
> >> (and Neptune's is so low to be so far from the Sun...)
> >
> > Could this have anything to do with Mercury's 3:2 rotational
> > resonance?
>
> I think it has more to do with General Relativity. The Mercury Anomaly
> was as a result of relativistic considerations.
If I'm not mistaken, GR tends to circularise orbits _faster_ due to
gravitational radiation. It should not have any influence toward
keeping the orbit eccentric.
Andrew Usher
John Smith
Yes! The Terranians miscalculated, and then had to send in General R.
from Starfleet Command to do the dirty work. Not much more than a
scorched cinder left of that planet now..
--
John
William Hamblen
The fact that we're here to argue about it speaks in favor of the long
term stability of the solar system.
BTW, "Nibiru" was the Babylonian term for the highest point of the
ecliptic. In ancient sky lore it wasn't a physical object at all.
Bud
John Smith
Yeah, whatever..
> So far it hasn't.
Not even of any kind? How wicked..
--
John
>
> Yousuf Khan
dlzc
On Sep 25, 8:07 am, Andrew Usher <k_over_hb...@yahoo.com> wrote:
> Yousuf Khan wrote:
> > >> What gets me is that Mercury has nearly the highest orbital
> > >> eccentricity in the system:
> > >>http://nssdc.gsfc.nasa.gov/planetary/factsheet/planet_table_british.html
> > >> (and Neptune's is so low to be so far from the Sun...)
>
> > > Could this have anything to do with Mercury's 3:2 rotational
> > > resonance?
>
> > I think it has more to do with General Relativity. The Mercury
> > Anomaly was as a result of relativistic considerations.
>
> If I'm not mistaken, GR tends to circularise orbits _faster_
> due to gravitational radiation.
Probably more like "frame dragging".
> It should not have any influence toward keeping the orbit
> eccentric.
Well, keep in mind the Sun-Jupiter barycenter is not inside the Sun.
So I suspect the variance is just due to the central mass moving
around so much. The "percentage" of a "fixed" motion on a smaller
basis just *looks* bigger?
David A. Smith
Andrew Usher
> > If I'm not mistaken, GR tends to circularise orbits _faster_
> > due to gravitational radiation.
>
> Probably more like "frame dragging".
>
> > It should not have any influence toward keeping the orbit
> > eccentric.
>
> Well, keep in mind the Sun-Jupiter barycenter is not inside the Sun.
> So I suspect the variance is just due to the central mass moving
> around so much. The "percentage" of a "fixed" motion on a smaller
> basis just *looks* bigger?
What does this have to do with Mercury's orbit? The question was why
Mercury's orbit has not been circularised by tides.
Andrew Usher
dlzc
If the center keeps being moved around, how in the world can it be
circularized? And of course it is possible that it has not been in
that position "forever".
David A. Smith
Yousuf Khan
Mercury (planet) - Wikipedia, the free encyclopedia
"The perihelion precession of Mercury is 5600 arc seconds per century.
Newtonian mechanics, taking into account all the effects from the other
planets, predicts a precession of 5557 seconds of arc per century.[78]
In the early 20th century, Albert Einstein’s General Theory of
Relativity provided the explanation for the observed precession. The
effect is very small: the Mercurian relativistic perihelion advance
excess is just 42.98 arcseconds per century, therefore it requires a
little over twelve million orbits for a full excess turn. Similar, but
much smaller, effects operate for other planets: 8.62 arcseconds per
century for Venus, 3.84 for Earth, 1.35 for Mars, and 10.05 for 1566
Icarus.["
http://en.wikipedia.org/wiki/Mercury_(planet)#Advance_of_perihelion
bert
>
> - Show quoted text -
Jupiter gives off 5% more energy than what it receives from the
Sun.Jupiter is the most active planet. It has bands and dark bands
would be bad light reflectors. Its huge "red" eye not a good
reflector.Its hydrogen and helium top layer could let light in but not
reflect it back easily?? TreBert