by neufer » Tue May 12, 2015 12:48 pm
Craine wrote:
It makes me wonder if Mars has anything like the Green Flash at sunset.
But then what color would it have? Would it be green? or perhaps more bluish, maybe even purple?
Though more likely the atmosphere is too thin to do anything like that.
The thin Martian atmosphere will still act as a prism but
a very weak one that will be overwhelmed by dust pollution.
Even on Earth the Green Flash is a
very low pollution phenomenon.
http://en.wikipedia.org/wiki/Green_flash#Green_rim wrote:
<<As an astronomical object sets or rises in relation to the horizon, the light it emits travels through Earth's atmosphere, which works as a prism separating the light into different colors. The color of the upper rim of an astronomical object could go from green to blue to violet depending on the decrease in concentration of pollutants, as they spread throughout an increasing volume of atmosphere. The lower rim of an astronomical object is always red.
A green rim is very thin and is difficult or impossible to see with the naked eye. In usual conditions, a green rim of an astronomical object gets fainter when an astronomical object is very low above the horizon because of atmospheric reddening, but sometimes the conditions are right to see a green rim just above the horizon.>>
Also, the Earth's Green Flash benefits greatly from orange/yellow Chappuis absorption bands of ozone forming a clean dark band break between the Sun's red image and the Sun's green image.
There is no ozone on Mars.
[quote="Craine"]
It makes me wonder if Mars has anything like the Green Flash at sunset.
But then what color would it have? Would it be green? or perhaps more bluish, maybe even purple?
Though more likely the atmosphere is too thin to do anything like that.[/quote][float=right][img3="[b][color=#0000FF]The upper rim is green while the lower one is red,
as the sun sets behind the Golden Gate Bridge.[/color][/b]"]http://upload.wikimedia.org/wikipedia/commons/1/16/Green_rim_of_the_setting_sun.jpg[/img3][/float]
The thin Martian atmosphere will still act as a prism but [b][u]a very weak[/u][/b] one that will be overwhelmed by dust pollution.
Even on Earth the Green Flash is a [b][u]very low pollution[/u][/b] phenomenon.
[quote=" http://en.wikipedia.org/wiki/Green_flash#Green_rim"]
<<As an astronomical object sets or rises in relation to the horizon, the light it emits travels through Earth's atmosphere, which works as a prism separating the light into different colors. The color of the upper rim of an astronomical object could go from green to blue to violet depending on the decrease in concentration of pollutants, as they spread throughout an increasing volume of atmosphere. The lower rim of an astronomical object is always red.
A green rim is very thin and is difficult or impossible to see with the naked eye. In usual conditions, a green rim of an astronomical object gets fainter when an astronomical object is very low above the horizon because of atmospheric reddening, but sometimes the conditions are right to see a green rim just above the horizon.>>[/quote]
Also, the Earth's Green Flash benefits greatly from orange/yellow Chappuis absorption bands of ozone forming a clean dark band break between the Sun's red image and the Sun's green image. [u]There is no ozone on Mars[/u].