What Does Sunset On an Alien World Look Like? 94
The Bad Astronomer writes "Using real data from Hubble Space Telescope of a planet orbiting another star, exoplanetary scientist Frédéric Pont created a lovely image of what sunset would look like from HD209458b, nicknamed Osiris, a planet 150 light years away. The Hubble data gave information on the atmospheric absorption of this hot Jupiter planet, and, coupled with models of how the atmosphere was layered, Pont was able to create a realistic looking sunset on the planet. The big surprise: the star looks green as it sets! Sodium absorption sucks out the red colors and blue is scattered away, leaving just the green hues to get through. It's a lovely application of hard scientific knowledge."
Re:And conveniently enough (Score:5, Interesting)
We are talking about how a star (which we can clearly measure) interacts with an atmosphere (which, again, we can clearly measure). Nothing as small or dark as Pluto needs to be measured to figure out what the "sunset" looks like. Comparing the two is highly specious. Not being able to directly image a dark, tiny rock is a lot different to being able to detect the atmosphere of a planet and the output of a (relatively) very bright star.
I guess it's best to leave this stuff to the professionals ;)
Re:And conveniently enough (Score:4, Interesting)
Indeed; they could easily figure out what a sunset would look like on one of Jupiter's moons by sending a probe. But the picture wouldn't look like what was predicted by computer model; I've never seen two sunsets that were exactly alike. Latitude, temperature, air pressure, etc -- there are too many variables. When I was stationed in Thailand in the Air Force I saw what I would have thought were breathtakingly beautiful sunsets at a certain time of year that contained all the colors there were, including green. You don't get sunsets like that this far north.
Re:And conveniently enough (Score:2, Interesting)
We can barely measure the star, and we certainly can't measure the atmosphere with any degree of certainty from 150 light years away. At best we can achieve is a few spectroscopic measurements of the absorption of upper atmosphere. This work is based on suspect modeling which in turn is based on a very tiny amount of data and nothing about the surface layers of the atmosphere.
Professionals indeed.