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May 7, 2008

Astronomers Get a Green Light

Posted: 01:01 PM ET

Just before the sun dips below the horizon, sometimes a brilliant green or blue flash appears at the edge of the fiery ball. To see it, you have to be somewhere with an unobstructed view of the sun and a very stable atmosphere.

Image courtesy and copyright Stéphane Guisard,

The perfect spot is the Cerro Paranal Observatory in Chile, perched on a 2,635-meter (8,645-foot) mountain in the Atacama Desert, where they get an average of 300 cloudless days per year. Check out these images, as well as another solar phenomenon called a "Gegenschein."

The observatory, which is operated by the 13-nation European Organisation for Astronomical Research in the Southern Hemisphere (ESO), is home to the Very Large Telescope (yes, that's the official name), which ESO describes as the world's most advanced optical instrument.

The green and blue flashes happen when Earth's atmosphere acts as a giant prism, refracting certain colors from the setting sun's rays. It's a tradition at Paranal for the staff to gather at sunset every day to watch for the flashes before settling down for a night of astronomical observations, according to the ESO Web site.

But kids, don't try this at home – at least not without proper eye protection. The ESO site emphasizes that looking at the sun with the naked eye is dangerous, and looking at it through a camera, binoculars, or telescope is even worse. "Do not attempt to observe the Sun unless you know what you are doing," the site warns repeatedly.

–Kate King, Writer,

Filed under: Astronomy • Sun

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Franko   May 7th, 2008 7:37 pm ET

Looks like a squashed pumkin with a stem on top.

Of course, the sunspots have disappeared since we reached a tipping point in CO2 concentration.

Amazing that adaptive optics telescopes can see through the distorting atmosphere better than the Hubble telescope can see outside the atmosphere.

David the 1/2 sane   May 8th, 2008 8:06 pm ET


Sunspots are on the sun, not on earth so I'm missing something. Are you saying that we can't _see_ the sunspots because of carbon footprint or that the sunspots don't _occur_ because of carbon footprint?

David the 1/2 sane

Franko   May 9th, 2008 1:22 am ET

A joke that only sane people, who are less smart than you understand

Possibly in poor taste needling the CO2 alarmists;
Not only changing global temperature, but also killing sunspots

Harley Simmons   May 11th, 2008 7:29 am ET

The Biggest Lie we could be living in is that the Sun is Round like a Planet, I belive it is a White Hole that the Earth and all the Planets
are Rotatin on the End of it and the Vortex Sun Tube extendes far into the Heavens and its Stability is controle by the Static Cold that
God in the Emptyness above all the Stars exist and Controls for each
and every one of us unless our Technologey in Space controles our
Magnetic Destiny in our Weather Maker.

If the End of the Sun is All we are able to see except at Sun Sets Green Streek of the Length of it .

Our Science Rocket servay differnt that the Sun is Round like a Planet .

I Wonder !!!!

Jason   May 12th, 2008 12:54 pm ET

The picture shows a distinct set of color bands...can you tell me why this occurs? Is is because of the atmosphere or something else? Additionally, the color shift looks fairly sharp, I would have thought that the color shift would have been very gradual.

Great picture!

Jason   May 12th, 2008 1:04 pm ET

I was also wondering when the green flash picture was taken? The blue flash image was taken at Christmas Eve...I'm just curious to see what time of year the green flashes occur or if there is a correlation of color hue and time of year/atmosphereic change.

Mike   May 12th, 2008 2:50 pm ET

That green flash explanation is wrong because scientist are looking at through atheistic telescopes. The right answer is that it is a Quaker colony on the sun as told by Brigham Young long ago when he said that Joseph Smith was right there are Quakers on the moon and also the sun too.

So I believe completely in what religious leaders tell me without question. Therefore that is a Quaker farm on the sun.

Larian LeQuella   May 12th, 2008 3:11 pm ET

LOL@Mike! Damn my atheist telescope, and here I thought Reality was so cool!

And Harley Simmons, please stop doing drugs! They are bad for you, okay? The only part of your post that made sense was that the sun isn't spherical,t hat is true, but the rest of it...

Nancy L. Bert   May 12th, 2008 7:00 pm ET

In reading my great great grandmother's diary from 1903, I noticed she wrote, "Eclipse of the sun. I seen it". She also wrote of a neighbor's also having looked at the eclipse. Later entries noted her having eye trouble and going to the doctor for "poison" to put on her eye. The neighbor was having similar problems. Grandma later went blind and never realized it was her having looked at the sun that caused her problem.

Jon Doe   May 12th, 2008 8:42 pm ET

Eclipse of the sun. I seen it too. But I weared protective glasses.

Jeff   May 13th, 2008 12:45 am ET

Kill all sunspots!

Jon   May 13th, 2008 10:35 am ET

"The sun isn't Spherical... thats true" I knew it was flat.. i just knew it. The church told me so.

Larian LeQuella   May 13th, 2008 1:56 pm ET

LOL@Jon. You folks are full of great zingers. It is approximately a sphere, a slightly flattened top to bottom (oblate) sphere to be precise! Again, that nasty requirement for precision in science. 😉

Franko   May 14th, 2008 6:35 am ET

The Sun's rotation flattens the poles. Jupiter and the Sun revolve around a center of gravity above the Sun's surface. That causes tides on the Sun. The conveyor belt, which moves the sunspots, is another factor to consider.

"The picture shows a distinct set of color bands"
Differential refraction, also likely similar processes as in a mirage, distorting and reflecting due to inversion layers. I wonder if in the ionosphere polarized ions contribute ?

Mike Steen   May 14th, 2008 7:12 pm ET

Having ALWAYS wanted to see the green flash, but living in a hilly area surrounded by trees, I have found my opportunities limited. Several years ago, though, my wife and I were having dinner on a deck overlooking the ocean in Maine. Tonight, I thought, I might see it. As the last of the sun was approaching the horizon, my wife said something to me, and I turned my head to reply and to take a (thoughtless) bite of my crab cake. At that moment I heard people exclaim, "Did you see it! Did you see the green flash?"
No, I don't blame my wife. I blame my STUPID STUPID INATTENTION!! AAAUUUGHHH!!!!

Larian LeQuella   May 19th, 2008 2:32 pm ET

Yikes, hope it was a good crab cake Mike (although if you were in Maine, I would have suggested lobster!). I have been fortunate to see the flash numerous times. The most amazing was when I was flying into the sunset on my way to Guam, at FL310 with a C-5 on the boom. Almost forgot what we were doing there for a moment!

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