Explanation: Back in 1979, NASA's Voyager 1 spacecraft flew past Jupiter and its moons. The images in this mosaic, featuring the moon Io against a background of gas giant Jupiter's diffuse swirling cloud bands, were recorded by Voyager's camera from a distance of about 8.3 million kilometers. The Io image from this mosaic may be the first to show curious round features on Io's surface with dark centers and bright rims more than 60 kilometers across. Now known to be volcanic in origin, these features were then thought likely to be impact craters, commonly seen on rocky bodies throughout the Solar System. But as Voyager continued to approach Io, close-up pictures revealed a bizarre world devoid of impact craters, frequently resurfaced by volcanic activity. Earlier this year a new robotic spacecraft, NASA's Juno, began to orbit Jupiter and last week made a pass within 5,000 kilometers of Jupiter's clouds. During the next two years, it is hoped that Juno will discover new things about Jupiter, for example what's in Jupiter's core.
I would love to see a side-by-side, to-scale image showing how large the Earth would appear from 8.3 million km compared to this image of Jupiter (taken from 8.3 million km). What a great way that would be to illustrate the enormity of this magnificent planet.
Jupiter has the largest planetary atmosphere in the Solar System, spanning over 5,000 km (3,000 mi) in altitude. Because Jupiter has no surface, the base of its atmosphere is usually considered to be the point at which atmospheric pressure is equal to 100 kPa (1.0 bar).
According to Wikipedia, the height of Jupiter's atmosphere is 5,000 km. What would be the color of the sky from the bottom of an extremely thick and cloudy 5,000 km high atmosphere? Pitch black, I would say.
Okay, what would be the color of the Jovian sky near its cloud tops? Well, it just might be the same color as most of the clouds, which mostly range from creamy white to light brick orange. Or else, who knows, it might be pitch black interspersed with a generous sprinkling of stars.
Does Jupiter have a blue sky anywhere? All I can say about it is that I have never seen a picture suggesting that it does. That doesn't necessarily mean there isn't a blue sky at some upper level of the atmosphere of Jupiter.
The northern hemisphere of Saturn can appear partly blue for the same reason that Earth's skies can appear blue -- molecules in the cloudless portions of both planet's atmospheres are better at scattering blue light than red.
The same mechanism must be responsible for making Pluto's atmosphere blue. It wouldn't surprise me if some thin upper part of Jupiter's atmosphere has the same property and color.
RocketRon wrote:... Even with just a trace of inter-mixing with the high wind speeds on Jupiter, over millions (billions ?) of years, would we expect to see the bands on Jupiter still so clearly defined ?
I think you're conceptualising this as: first there were bands, then mixing occurred, so there shouldn't be bands now. But I see the bands as being analagous to standing waves. Whatever mixing is occurring, there will still be bands, because the forces that produce them continue. No doubt the bands are evolving over time, but they continue. And the strongest evidence for evolving bands is that we see them today, more than 4 billion years after the planet began to form.