Why do some planets revolve in the opposite direction?

I was watching a documentary called "101 Why Evolution is Stupid"
(you've got to keep up on the other side) and the speaker said that a
physicist couldn't explain how some planets revolve opposite of the
others. The anomoly to him was that if the solar system was formed from
a whirling disk of matter then all matter in the solar system would
follow that either clockwise or counter-clockwise motion b/c of
centrifugal motion. I don't believe that God just placed a couple
planets in different revolutions just to give an argument over to
creationism. So I come to you guys to help grasp why this is.

wrote:
I was watching a documentary called "101 Why Evolution is Stupid"
(you've got to keep up on the other side) and the speaker said that a
physicist couldn't explain how some planets revolve opposite of the
others. The anomoly to him was that if the solar system was formed from
a whirling disk of matter then all matter in the solar system would
follow that either clockwise or counter-clockwise motion b/c of
centrifugal motion. I don't believe that God just placed a couple
planets in different revolutions just to give an argument over to
creationism. So I come to you guys to help grasp why this is.


Most likely the result of collision with other large bodies in
the earlier solar system.

The should watch the 4-hour "Origins" series that aired on PBS
in the last year or two--pretty up to date with good visual
animations.
http://www.pbs.org/wgbh/nova/transcr...3_origins.html

wrote:
I was watching a documentary called "101 Why Evolution is Stupid"
(you've got to keep up on the other side) and the speaker said that a
physicist couldn't explain how some planets revolve opposite of the
others. The anomoly to him was that if the solar system was formed from
a whirling disk of matter then all matter in the solar system would
follow that either clockwise or counter-clockwise motion b/c of
centrifugal motion. I don't believe that God just placed a couple
planets in different revolutions just to give an argument over to
creationism. So I come to you guys to help grasp why this is.

In a word: "collisions." Or near-collisions, if the target planet is
oblate. At least that's the presumed origin of the retrograde rotation
of Venus and Uranus. They can't *prove* that such a collision occurred,
of course, but it's a plausible explanation. How the program went from
"plausible explanation" (which it is) to "couldn't explain how" ...
well, perhaps they asked the wrong kind of physicist. (I'd like to be
able to give the producers the benefit of the doubt.)

-- Bill Owen

" wrote in
oups.com:

I was watching a documentary called "101 Why Evolution is Stupid"
(you've got to keep up on the other side) and the speaker said that a
physicist couldn't explain how some planets revolve opposite of the
others.

The speaker was telling lies. I wouldn't be surprised if it was none other
than Kent Hovind. The cretinist with the mail order degree.

The anomoly to him was that if the solar system was formed from
a whirling disk of matter then all matter in the solar system would
follow that either clockwise or counter-clockwise motion b/c of
centrifugal motion. I don't believe that God just placed a couple
planets in different revolutions just to give an argument over to
creationism. So I come to you guys to help grasp why this is.


The interaction of bodies through collisions and other interactions tends
to smooth out and flatten the proto planetary disk. Individual collisions,
asteroid capture etc often vary from the overall trend. Retrograde moons
for example are considered to be a good sign that they are captured objects
rather than formed in situ. Intrinsic rotation OTOH is the result of a
combination of collisions and tidal interaction.

Klazmon.

Llanzlan Klazmon wrote in
7.6:

" wrote in
oups.com:

I was watching a documentary called "101 Why Evolution is Stupid"
(you've got to keep up on the other side) and the speaker said that a
physicist couldn't explain how some planets revolve opposite of the
others.

The speaker was telling lies. I wouldn't be surprised if it was none
other than Kent Hovind. The cretinist with the mail order degree.

The anomoly to him was that if the solar system was formed from
a whirling disk of matter then all matter in the solar system would
follow that either clockwise or counter-clockwise motion b/c of
centrifugal motion. I don't believe that God just placed a couple
planets in different revolutions just to give an argument over to
creationism. So I come to you guys to help grasp why this is.


The interaction of bodies through collisions and other interactions
tends to smooth out and flatten the proto planetary disk. Individual
^^^^^^^^^
********** meant to say clump**************

collisions, asteroid capture etc often vary from the overall trend.
Retrograde moons for example are considered to be a good sign that they
are captured objects rather than formed in situ. Intrinsic rotation OTOH
is the result of a combination of collisions and tidal interaction.

Klazmon.

I had a similar question as a kid, when images of Saturn's rings showed
that some were actually braided, simply amazing, how could it be.

I'm guessing as an old man that, in Saturn's case, it has to do with
gravitational fields and resonance; nodes and such. Amazing Universe,
ain't it?

rat
~( );

wrote:
I was watching a documentary called "101 Why Evolution is Stupid"
(you've got to keep up on the other side) and the speaker said that a
physicist couldn't explain how some planets revolve opposite of the
others. The anomoly to him was that if the solar system was formed from
a whirling disk of matter then all matter in the solar system would
follow that either clockwise or counter-clockwise motion b/c of
centrifugal motion. I don't believe that God just placed a couple
planets in different revolutions just to give an argument over to
creationism. So I come to you guys to help grasp why this is.

wrote:
I was watching a documentary called "101 Why Evolution is Stupid"
(you've got to keep up on the other side) and the speaker said that a
physicist couldn't explain how some planets revolve opposite of the
others. snip

A minor correction in terms. You meant to say "rotation" not
revolution. All the major nine planets revolve around the Sun in the
same counterclockwise direction and all carry all of their satellites
with them in that direction of revolution around the Sun.

Most major planets rotate around their primary axis in counterclockwise
direction. Earth is in this group.

As others have noted:

1) Some major planets appear to rotate about their axises in a
clockwise direction. This visual appearance occurs when the
inclination of the planet's equator to the eclipitic is greater than 90
degrees. These planets were initially rotating counterclockwise,
consistent with the "whirlpool analogy" but appear to rotate clockwise
when their current axis of rotation is highly tilted with respect to
the ecliptic - the plane of the solar system. (Use a basketball to
simulate the effect. Rotate it in one direction and then look at it
from the top and bottom.) Looking at my Allen's Astrophysical
Quantities, those planets a

Planet Planet equator tilt with respect to ecliptic degrees
Venus 177.3
Uranus 97.86
Pluto 119.61

In the case of Venus, based on computer simulations, tidal friction
with a planet's atmosphere can accrue over billions of years, can slow
a planet's rate of rotation and cause it to wobble. Collisions are
another source of wobble. If the wobble grows large enough, the planet
"flips over" with respect to the orbit plane and appears to rotate in a
retrograde or clockwise motion.

A moon, like the Earth's Moon, can dampen this effect can keep a planet
from from flipping. Even so, the Earth's tilt over geologic time has
varied significantly. The Moon is in part responsible for life on
Earth. Without it, the Earth may have spent part of geologic history
with the North or South pole pointing at the Sun. Under such an
orientation, the Earth would not be a very hospitable place for life to
form.

2) A simiilar rotation and inclination situation occurs with respect to
some satellites around some major planets. Referring to Allen's
again:

Planet Moon Inclination
Saturn Phoebe 177
Uranus Caliban 139.2
Uranus Sycroax 152.7
Pluto Charon 96.2

In the case of the outer gas giants Saturn and Uranus, their moons are
captured Kuiper belt objects that may have entered the inner solar
system at a high angle or may have been hit by other Kuiper Belt
objects after they entered the gas giant's orbit. The "whirlpool"
analogy does not properly apply to them.

With respect to Saturn, note that the rings are geologically relatively
young - less than 100 million years. It is only by the constant
replinishment of Saturn's moon system with new captured moons from the
Kuiper Belt, that Saturn's rings could continue to exist.

With respect to Uranus, its five primary moons are geologically very
diverse - evidence of their captured nature. They are so diverse, it
is unlikely that they could have formed in place around Uranus.

The same principle, high angle capture, applies to Charon and Pluto,
which themselves are Kuiper belt objects.

To get a feel for the role of the Oort Cloud and the Kuiper Belt as the
"pool cues" in the cosmic game of billards in which the inner solar
system planets are the targets, illustrations in the following links
may give you a proper sense of scale:

http://en.wikipedia.org/wiki/Kuiper_Belt
http://www.cfa.harvard.edu/iau/Anima...nimations.html
http://www.cfa.harvard.edu/iau/Anima...OuterSmall.gif (1.2 megs)

Hope that helps.

- Canopus56

wrote in message oups.com...
I was watching a documentary called "101 Why Evolution is Stupid"
(you've got to keep up on the other side) and the speaker said that a
physicist couldn't explain how some planets revolve opposite of the
others.

None of the planets in the solar system "revolve" opposite others.
Was the Evolution stupidist using the word rotate in place of
revolve? As others have mentioned collisions could have
radically reoriented the axis of the "improper rotators".

The anomoly to him was that if the solar system was formed from
a whirling disk of matter then all matter in the solar system would
follow that either clockwise or counter-clockwise motion b/c of
centrifugal motion. I don't believe that God just placed a couple
planets in different revolutions just to give an argument over to
creationism.

God did give us brains to ask and try to
answer these questions. Too bad creationists believe
we should freeze those brains in the dark ages.

--

Hilton Evans
---------------------------------------------------------------
Lon -71° 04' 35.3"
Lat +42° 11' 06.7"
---------------------------------------------------------------
Webcam Astroimaging
http://mysite.verizon.net/hiltonevan...troimaging.htm
---------------------------------------------------------------
ChemPen Chemical Structure Software
http://www.chempensoftware.com

Kurt (canopus56) wrote:
A minor correction in terms. You meant to say "rotation" not
revolution. All the major nine planets revolve around the Sun in the
same counterclockwise direction and all carry all of their satellites
with them in that direction of revolution around the Sun.

The latter is not true (unless I misunderstand you). Triton revolves
around Neptune in the retrograde direction. It is the only sizable
satellite to do so in the solar system, but besides Triton, many other
smaller satellites (such as a lot of the small outer satellites of
Jupiter) are also retrograde.

--
Brian Tung
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

Rick Evans wrote:
wrote in message oups.com...
I was watching a documentary called "101 Why Evolution is Stupid"
(you've got to keep up on the other side) and the speaker said that a
physicist couldn't explain how some planets revolve opposite of the
others.

None of the planets in the solar system "revolve" opposite others.
Was the Evolution stupidist using the word rotate in place of
revolve? As others have mentioned collisions could have
radically reoriented the axis of the "improper rotators".

The anomoly to him was that if the solar system was formed from
a whirling disk of matter then all matter in the solar system would
follow that either clockwise or counter-clockwise motion b/c of
centrifugal motion. I don't believe that God just placed a couple
planets in different revolutions just to give an argument over to
creationism.

God did give us brains to ask and try to
answer these questions. Too bad creationists believe
we should freeze those brains in the dark ages.

--

Hilton Evans
---------------------------------------------------------------
Lon -71° 04' 35.3"
Lat +42° 11' 06.7"
---------------------------------------------------------------
Webcam Astroimaging
http://mysite.verizon.net/hiltonevan...troimaging.htm
---------------------------------------------------------------
ChemPen Chemical Structure Software
http://www.chempensoftware.com

You give a Lat/Long coordinate in your signature reflecting a
geographical point on the Earth with the Longitude meridian a truly
global coordinate stretching from pole to pole.A truly wonderful
coordinate system we inherited from our astronomical ancestors,made
even more exquisite when Copernicus discovered and argued for the
Earths' axial and orbital motions and while these motions,in their
daily and annual form are compounded together,they can be seperated
into independent motions serving different purposes.

I assure you that the creationists appear quite sensible when compared
to those who base their observations on the Ra/Dec system in justifying
the Earth's rotation to the celestial sphere in 23 hours 56 min 04 sec
-

http://www.opencourse.info/astronomy...phere_anim.gif

The problem is not that you and your colleagues get a perverse
satisfaction from what you do,the problem is that you know no
better.The insult falls on generation after generation for over 3
centuries and with each passing era,the great intuitive instincts which
drove Western civilisation to those great achievements in heliocentric
astronomy has been all but extinguished,replaced by a silly piece steel
and mirrors.

There is a reason why the Earth has an independent axial rotation and
why the
rotational pace is, and always will be, 15 degrees of rotation per hour
and 24 hours/360 degrees in total.To argue for an alternative value
makes a person far more damaging than a creationists,in all
respects,because an alternative value was chosen in the 17th century
give rise to the creationists .