green flash venus 2018
© Paolo Palma
Green Flash Of Venus
Taken by Paolo on September 29, 2018 @ Roma
Green flashes on the sun are so rare, they were once thought to be mythological. Saturday evening in Rome, Paolo Palma witnessed a green flash with real ties to mythology: A green flash on Venus. "The planet was low on the horizon and its light looked like a long fiery bubble, with flames of red, orange, yellow and green," says Palma. "When Venus went below the horizon, the last ray was clearly green in color."

"I took this picture using my smartphone at the eyepiece of a 12-inch telescope at 76x magnification," he says.

Green flashes on the sun are formed when the prismatic action of the atmosphere splits the setting sun into basic R-G-B colors. Temperature inversions (usually above a sea surface) create a mirage, magnifying the green into an eye-catching flash. The same physics created this green flash on Venus. "The sea is only 8 km away from me!" notes Palma.

Now is a good time to look for green flashes on Venus. The second planet is approaching the sun and thinning into a narrow crescent--like a miniature crescent Moon. The long skinny profile of Venus is easily split into R-G-B colors as it beams over the horizon, setting the stage for beautiful atmospheric optics.