Venus' Morphing Vortex Trumps Saturn's Hexagon

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[atsimg]http://files.abovetopsecret.com/images/member/7e1ddc41165a.gif[/atsimg]

New analysis of images taken by ESA's Venus Express orbiter has revealed surprising details about the remarkable, shape-shifting collar of clouds that swirls around the planet's South Pole (left). This fast-moving feature is all the more surprising since its centre of rotation is typically offset from the geographical pole.

Several planets in the Solar System, including Earth, have been found to possess hurricane-like polar vortices, where clouds and winds rotate rapidly around the poles. Some of these take on strange shapes, such as the hexagonal structure on Saturn.

"The longevity of Saturn's hexagon makes this something special, given that weather on Earth lasts on the order of weeks," said Kunio Sayanagi, a Cassini imaging team associate at the California Institute of Technology. "It's a mystery on par with the strange weather conditions that give rise to the long-lived Great Red Spot of Jupiter."

Now tell me that's not super cool?

More unexplained happenings in our Solar system?

Especially something that rivals Jupiter's red spot? Wow.

As someone that studies abnormalities like this, there's nothing better than a good mystery.

Any thoughts?

Pred...

This animation is a reconstruction of the motion of the polar atmosphere of Venus, created by taking 3.8 micron radiance maps of the polar region, obtained during May 2007, and applying a shift (a rotation and translation) to the image based on the measured wind speeds. The cross marks the South Pole and the white circle marks the centre of rotation of the polar atmospheric vortex. The outer edge of the figure is the latitude circle of 75 degrees.

thanks for sharing

reply to post by iforget


Your welcome buddy and thanks for the reply. It's a little slow in here tonight or maybe were just nerds.

I thought this would have sparked a little more interest and replies.

Pred...

reply to post by predator0187
I don't think it trumps Saturn's hexagon, that even trumps Jupiter's red spot in my book, but this is pretty cool.

And it does seem odd that it's not centered at the pole like we might expect. I finally saw an explanation of Saturn's hexagon in a lab experiment, maybe they'll eventually be able to explain this too.

It's pretty cool we can tell this much about the weather on other planets...now if we can just get the weathermen here on Earth to be more accurate...they say there's a 50% chance of rain tomorrow...how can they be wrong with a prediction like that?

For a guy like me who doesn't study anomalies like this, Saturn's hexagonal polar vortex, or Jupiter's red spot, I wonder if at least for Venus's and Saturn's polar anomalies are due to their extremely long 'days'. Venus is defiantly an interesting bird. Venus's axial tilt is so great that its north pole faces down, this making it rotate in a retrograde direction, (the sun rises in the west and sets in the east on the surface of Venus. Its the upside down planet). It also has the most perfect circular orbit in the solar system.

Being less than 3º of perfectly upside down I wonder if this vortex isn't centered near the same degrees off of the pole in respect to it's axial tilt, or 2.7 degrees from the pole? It probably has nothing to do with the tilt and more to do with the atmospheric pressure and long half-year Venusian day.

Being as the only planet associated with a feminine name, all things Venus being turned upside down makes perfect sense to me. *smile*

Originally posted by Illustronic
Venus's axial tilt is so great that its north pole faces down, this making it rotate in a retrograde direction, (the sun rises in the west and sets in the east on the surface of Venus. Its the upside down planet). It also has the most perfect circular orbit in the solar system.

Hmmm, I'm not sure about that.

I'm not sure, but I think you can either say:
- its North pole is above the ecliptic so its motion is retrograde, in which case the sun rises in the west, or
- its upside down so the North pole is below the ecliptic, and the sun rises in the East.
But it doesn't sound right to say it's upside down and the sun rises in the West.

Some more info on the definition of North:
www.idialstars.com...

By convention we think of north as "up" and south as "down." We tend to view the Earth's North Pole as being "above" the ecliptic (Earth's orbital plane) and the South Pole as being "below" it. But since Venus' North Pole points "down" while its South Pole points "up," Venus throws a monkey wrench into this accustomed way of looking at things. Because the north pole of a planet -- by definition -- belongs to the hemisphere that rotates counter-clockwise, Venus' North Pole points south of the ecliptic.

However, after consulting a number of astronomers, I'm not so sure there's a firm concensus on the definition of "north pole." Apparently, some feel a planet's north pole is the one that points north of the ecliptic, regardless of the planet's rotational direction. ...

NOTE: Years after having written this article, I read the following on page 299 of More Mathematical Astronomy Morsels by Jean Meeus: "In 1970 the International Astronomical Union (IAU) decided that the rotational pole of a planet or satellite that lies on the north side of the invariable plane of the solar system shall be called north. (This plane is close to that of the ecliptic.) We regret this decision and would prefer that the north pole be the one above which an observer sees rotation in the direct (counterclockwise) sense. Thus, for instance, Venus' north pole would be south of the ecliptic. Our definition does not depend on a particular reference frame, eliminates negative rotation rates and simplifies the mathematics."

I don't know if the IAU ever reversed its definition or not but apparently both definitions of North are used so I wouldn't argue with either one, but I would argue with using both definitions at the same time.

It would be a lot less confusing for us if they would just pick one definition for north, right? When I see something about the North Pole of Venus, I'm not sure which definition they're using, the above the ecliptic definition, or the counterclockwise direction of rotation definition. I'm also not sure of the IAU definition of East and West, but the dictionary definition says something about East being the direction of Sunrise so I'm wondering if that may be why the IAU regretted the decision to define North as above the ecliptic, and wish they had defined it as the hemisphere where rotation is counterclockwise instead?

Back on topic, the OP article refers to the south pole of Venus, and I have no idea which definition of south pole they are using?

Axial tilt of Venus is 177.3º, making it nearly upside down, making its revolution opposite all other planets (retrograde rotation) except Uranus, which is nearly perfectly sideways to the sun, Uranus north pole faces the sun. One can call the south pole north on Venus and say it rotates backwards, or one can determine its axial tilt is 2.7 degrees off of upside down and it rotates the same direction of all the other planets. Either way, its different.

en.wikipedia.org...

Nothing to do with its orbital plane.

Originally posted by predator0187
reply to post by iforget

 

Your welcome buddy and thanks for the reply. It's a little slow in here tonight or maybe were just nerds.

I thought this would have sparked a little more interest and replies.

Pred...

Yep, just Nerds and family type people are here on a Saturday night...the cool cats are in their showers scrubbing down their dirty little bodies, readying themselves for an evening of excess booze, excess drugs and excess sex...i'm getting ready for an evening of excess jealousy!


I saw a refreshing documentary a year ago on the BBC (Horizon) called 'Is everything we know about the universe wrong?'

It featured main stream, well known physicists and astrophysicists that basically, all pretty much agreed that we know virtually nothing about 'out there' in space, and what we do know and write theories about may be completely wrong!

Refreshing, i thought.

This Venus phenomena is just another example of how little we comprehend about our own Solar system, let alone our Universe!

reply to post by Illustronic
The definition that says "North" is where the counterclockwise rotation occurs has nothing to do with the orbital plane, I would agree with that.

But the 1970 definition of "North" from the International Astronomical Union is related to the "invariable plane of the solar system" which pluto deviates from significantly but the 8 planets far less so. So I think it's a stretch to say that definition isn't related to the orbital plane, it's really related to the orbits of all the planets not just Venus.

Originally posted by Arbitrageur
reply to post by Illustronic

 

The definition that says "North" is where the counterclockwise rotation occurs has nothing to do with the orbital plane, I would agree with that.

But the 1970 definition of "North" from the International Astronomical Union is related to the "invariable plane of the solar system" which pluto deviates from significantly but the 8 planets far less so. So I think it's a stretch to say that definition isn't related to the orbital plane, it's really related to the orbits of all the planets not just Venus.

Strange though isn't it?

I mean, it *must* be at least partly an arbitrary definition, because who decided one side of the orbital plane is North and the other South?

But then i suppose we need to orient ourselves somehow.

reply to post by Arbitrageur


We've learned a lot since 1970, I would postulate that first. If we have no basis of determinations then we are all throwing darts, some better than others. But if we observe consistencies in nature that prove to be consistently uniform, then we have a starting point at which to compare things with. Thats simply the scientific process at work while Peer Review substantiates.

Without that as a starting point, what is the point to begin with? Believe everything out there/in here?


It's easier to tell these days if a planet is rotating the opposite direction the sun is, it wasn't always the case, since we really can't see the Venetian surface. We have better math now, and a much longer observational control group, we haven't had then.

I just for the hell of it will side with the planet is rotating the same direction (in respect to itself), only upside down (in respect to the sun). We do know what direction we go around our sun is you know, those that rotate the same way and those that don't, is easily determined now days. There are many moons with retrograde rotations around Saturn and Jupiter, which could be considered 'their sun' but they aren't upside down, like Venus.

Originally posted by Illustronic
I just for the hell of it will side with the planet is rotating the same direction (in respect to itself), only upside down (in respect to the sun).

That's the definition wiki uses which makes sense to me also. But do you agree that using that definition, the sun rises in the East on Venus?

There are plenty of sites on the internet claiming the sun rises in the West, and I can't say they're wrong since they used the 1970 international definition of North. But I think they'd be wrong according to the more updated definition Wiki is using for North.

reply to post by Arbitrageur


Well at least on Earth we know north is where Santa has his base, and the south is where the Nazis took Hitler to their base. (kidding)

I frankly never really considered what parameters determine north and south, I'm a true layman in these things, interested in learning more especially since browsing ATS these last few years. Thanks for your shared knowledge and views.

I suppose sometimes I'm just throwing darts to see what sticks. You know the blind squirrel thing.