Do you believe in the Green Flash?
Monday, March 13th, 2006Every evening the astronomers here on Paranal gather at the foot of the telescopes to watch the sun set - and maybe see the Green Flash. When the sun sets behind a very flat surface, such as the sea, the final dot of light can flash green for a second or more (see the Science Bit below). But it is very rare here, and many folk have never seen it, even after months of watching, and get rather cynical and unbelieving!
Being from a cloudy country (and rainy, misty, hilly etc) I had also never seen it before coming to Chile. Even now, we have only seen it at the coast, with our friend Mairi. From Paranal we are looking over the clouds, which are not very flat, so it is very rare here. But every night we go out in the cold, get some fresh air (slightly rarified) and hope! The sunsets are beautiful anyway. Tonight they should be stunning as there are some higher clouds to reflect the light. I think I am not made to be an astronomer as I like clouds too much!
(The science bit - in simple terms, the final rays of light are bent by the atmosphere so that the redder light disappears before the bluer light. The bluest light is scattered by the atmosphere, hence the sky being blue, and so we see the green light.)