Post by Professional Keyboard Goblin / Redsky

Wow! I've never seen it that up-close before! I had no idea It had those blue sections.

dec 27, 2024, 6:26 pm • 1 0

Replies

yeah! There's some real nice images (namely from Juno iirc) that show Jupiters poles, which appear more blue in part because of colour enhancing!

image of Jupiter's south pole. the swirling gasses are colour enhanced and appear more blue towards the pole.

dec 27, 2024, 6:34 pm • 1 0 • view

What causes the blue? Is it some kind of gas? Radiation?

dec 27, 2024, 8:25 pm • 1 0 • view

I knew a little bit about it, but this reply on a thread is a lot more in depth about it and honestly that's where I learned about it from in particular!

a reply from a Reddit thread from user Astromike23. it reads: Gases near the poles are definitely more red-absorbing. That comes across in human vision as bluish - or at least bluer than most other parts of the planet - so this is not just an effect of enhanced camera filters. Note that there are also blue areas near the equator of Jupiter (caused by Rayleigh scattering, the same thing that causes blue skies in clear air on Earth) but those are in the largely cloud-free 5-micron Hot Spots, where the atmospheric path length is considerably greater. In essence, you need a lot of cloud-free air before you can see the blues of Rayleigh scattering, whether on Jupiter or Earth. The reason for the blues we see in polar regions likely has a different explanation, potentially due to a combination of 1) the changes in stratospheric haze composition in high-latitude regions (e.g. Orton, et al, 2019), although the exact chromophore is yet to be identified, and 2) sunlight has a longer path length through the upper atmosphere near the poles since it enters the atmosphere at an oblique angle. That means light encounters more methane (as well as other hydrocarbons) in the upper atmosphere near the poles before it hits cloud-top; methane is a compelling candidate gas here, since it absorbs red light strongly. We also see composition differences in polar hazes across latitudes on Saturn (where the poles also tend to look bluish), with considerably different mixing ratios of methane and acetylene as one goes from equator to pole. It's believed a lot of the composition difference there is due to UV photochemistry, so it's quite possible a similar mechanism is at play on Jupiter, as well. Source: did my PhD researching giant planet atmospheres.

dec 27, 2024, 8:33 pm • 0 0 • view