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Wow! If anyone is curious as to why Triton is so bright... > Covered in a frozen sheen of condensed nitrogen, Triton reflects an average of 70 percent of the s
by cl42 4y ago
Wow! If anyone is curious as to why Triton is so bright...
> Covered in a frozen sheen of condensed nitrogen, Triton reflects an average of 70 percent of the sunlight that hits it. It far outshines Neptune in this image because the planet’s atmosphere is darkened by methane absorption at these near-infrared wavelengths.
That's pretty neat!
- ajross 4y agoAlso explains why the rings are brighter than the planet here, when they were all but invisible to Voyager 2.
- pastor_bob 4y agowoah I originally thought it was a star
- MiguelVieira 4y ago> 70 percent of the sunlight that hits it It looks like that's comparable to fresh snow or a glacier?
- Cerium 4y agoBetter than a glacier but worse than fresh snow. "More than 80 to 90 percent of the sunlight falling on fresh snow is reflected back into space, compared to 15 to 35 percent of the sunlight reflected by most ice."[1]. [1]https://earthobservatory.nasa.gov/features/DirtySnow/page2.php https://earthobservatory.nasa.gov/features/DirtySnow/page2.p...
- echelon 4y agoIs there a good chemical / spatial argument for why this is so?
- cma 4y agoI think it is because a flat surface gets one chance to reflect by refraction and predominantly only at a shallow angles. A bunch of micro surfaces in an aggregate formation mean it could bounce around multiple times and then head out, or pass through the ice medium and then bounce back out when it exits and reflects off more. Absorption wise a greater ratio of air to ice means it will absorb less often too over the same distance through snow.
- Yeahsureok 4y agoThis is correct, it's why things like solar panels have a surprisingly low albedo despite being mostly black, they are completely flat.
- bcbrown 4y agoThe fact that methane absorbs infrared/near-infrared frequencies is also the mechanism that causes it to be a greenhouse gas.
- jacobolus 4y agohttps://en.wikipedia.org/wiki/Neptune#Internal_structure https://en.wikipedia.org/wiki/Neptune#Internal_structure > "At a depth of 7,000 km, the conditions may be such that methane decomposes into diamond crystals that rain downwards like hailstones.... the top of the mantle may be an ocean of liquid carbon with floating solid 'diamonds'."
- eredengrin 4y agoThanks for pointing this out, that is truly fascinating to imagine. I'm now short on sleep due to the wikipedia rabbit hole :)