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Turbulence in Saturn's Atmosphere
neutron_p writes "Today an image of turbulence in the atmosphere of Saturn has been unveiled. This image was taken with the NASA/ESA/ASI Cassini-Huygens spacecraft camera. This pattern is an example of a 'Kelvin-Helmholtz instability', which occurs when two fluids of different density flow past each other at different speeds. This phenomenon should be common on the gas-giant planets."
This is a cool picture - but how exactly is this news, and why should we be excited?
Because it's posted in the science section of Slashdot and a tremendous amount of us geeks keep an eye on all things space and science related?
The fact that we're in the middle of learning/confirming/discovering stuff about our own solar system is both News For Nerds and Stuff That Matters.
What do you expect, baseball highlights?
Lost at C:>. Found at C.
wouldnt we get better performance long-term from a larger number of smaller probes?
Most of the cost goes into getting to these very far away places and holding enough propellent that you can slow down enough to be captured into orbit after you've been going very fast for a few years. It's not feasible to launch probes to outer planets all the time because you lose the ability to "sling shot" past other planets as a cheap way to pick up a lot of speed. These gravity assist (or more accuratley, angular momentum assist) moves make a little ship go whole heck of a lot faster which means you don't need as much propellent to get you somewhere. You have to go really fast to someplace that several billion miles away in a few years.
and hence would have more up-to-date sensors. For example, the CCD on the Cassini camera is only 1 megapixel!
The way to get better quality pics is NOT to have more pixels but to have better optics. The cameras in the "eyes" of the Mars Exploration Rovers (the pancam) are only about 1 megapixel and they have returned VERY high resolution pics that look great if you have to blow them up 10 times their size. That's because NASA spends a lot of money to use phenomonally good optics. In addition, more megapixels means larger files which requires higher data transfer rates which requires more power to your antenna which means less electricity to do other stuff. (whew)
I have heard it suggested that most of the useful function of the JIMO $10 billion orbiter could be done with a simpler $1 billion direct-to-europa mission.. And look at New Horizons, with a mission cost less $1 billion, or SMART-1 less than $100 million..
Dude, compare apples to apples here. SMART-1 is a test of new technology (ion drive) that is meant to see how well it works and if it useable in other missions. It was meant to be a cheap way to get to the moon. You don't need a whole lot of force to get the moon and orbit it if you're willing to wait a few years...like SMART is. To get to Jupiter and then ORBIT it, you have to go very fast to get there, then be strong enough to slow down to be captured into orbit. Then maybe you'd want a few kilos of propellent left to actually move around near Jupiter for a few year. That is a completely different scope than crusing along to the moon for several years or flying by Pluto-Charon before the atmosphere freezes out.
The turbulence tastes fractally!
"Wow. Now THAT'S a lot of angry Indians." - Lt. Col. George Armstrong Custer
Saturn: "I can do what Jupiter does also, neener neener!"
Table-ized A.I.
1.Gas planets are huge wave machines
2.???
3.Profit!
Instead of raising your voice, try strengthening your argument.
Quite an impressive animation. I want one on a a globe. :)
Higher res pics can be found here
Before you start jumping up and down here,
:-)
Seems to me you are the one doing the jumping..
(Wouldnt we get better performance long-term from a larger number of smaller probes?)
Most of the cost goes into getting to these very far away places and holding enough propellent that you can slow down enough to be captured into orbit after you've been going very fast for a few years. It's not feasible to launch probes to outer planets all the time because you lose the ability to "sling shot" past other planets as a cheap way to pick up a lot of speed. These gravity assist (or more accuratley, angular momentum assist) moves make a little ship go whole heck of a lot faster which means you don't need as much propellent to get you somewhere. You have to go really fast to someplace that several billion miles away in a few years.
Yes, I understand that. In fact its not all that bad - an opportunity to use Jupiter to sling-shot comes round every 13 months. For example, New Horizons will launch Jan 2006 for Pluto, mission cost $600 million. If a second identical probe is built for a follow up around 2008, we can get a fly-by of Uranus and then some more KBO's, for an even smaller cost. Probes like SMART-1 also conserve power by making careful use of other celestial mechanics & tricks - "lunar resonances", check the ESA site. There are "interplanetary highways" that could even provide "free" trips between planets, all be it slowly..
(and hence would have more up-to-date sensors. For example, the CCD on the Cassini camera is only 1 megapixel!)
The way to get better quality pics is NOT to have more pixels but to have better optics. The cameras in the "eyes" of the Mars Exploration Rovers (the pancam) are only about 1 megapixel and they have returned VERY high resolution pics that look great if you have to blow them up 10 times their size. That's because NASA spends a lot of money to use phenomonally good optics. In addition, more megapixels means larger files which requires higher data transfer rates which requires more power to your antenna which means less electricity to do other stuff. (whew)
Even within limited Bandwidth, higher resolution can prove useful - remember Galileo which busted its high gain antenna, and could only send data to earth at a low data rate? It still did 90% of the science it was supposed to do anyway, by careful use of resources.. I am not saying Cassini is not worthwhile - the results are/will be fascinating. I just believe that smaller/cheaper missions turn around faster and actually put up more modern devices within a given timescale..
(I have heard it suggested that most of the useful function of the JIMO $10 billion orbiter could be done with a simpler $1 billion direct-to-europa mission.. And look at New Horizons, with a mission cost less $1 billion, or SMART-1 less than $100 million..)
Dude, compare apples to apples here. SMART-1 is a test of new technology (ion drive) that is meant to see how well it works and if it useable in other missions. It was meant to be a cheap way to get to the moon. You don't need a whole lot of force to get the moon and orbit it if you're willing to wait a few years...like SMART is. To get to Jupiter and then ORBIT it, you have to go very fast to get there, then be strong enough to slow down to be captured into orbit. Then maybe you'd want a few kilos of propellent left to actually move around near Jupiter for a few year. That is a completely different scope than crusing along to the moon for several years or flying by Pluto-Charon before the atmosphere freezes out.
This is not something I am just pulling out of the air here - for example check this article from SpaceDaily. http://www.spacedaily.com/news/hubble-04p.html
We could get to orbit Europa (the main satellite of interest) with a much cheaper mission than JIMO - about 1 billion should do it. In fact, and this is my origin
"You lied to me! There is a Swansea!"