20 Most Incredible Light Phenomena [pics] Set 2

20 Most Incredible Light Phenomena [pics]

Light Displays

Aurora

Image courtesy of US Air Force Senior Airman Joshua Strang

The collision of electronically charged particles in the earth’s upper atmosphere often creates magnificent light displays over the polar regions. The colour depends on the elemental content of the particles – most auroras appear green or red due to oxygen, however nitrogen sometimes creates a deep blue or violet appearance. This particular display is the famous Aurora Borealis or Northern Lights, named after the Roman goddess of dawn, Aurora, and the ancient Greek for the northern wind, Boreas.

Contrails

Image by Jasmic_is_back_in_the_building

The vapour trails that follow aircraft through the sky cause stunning man-made patterns in the atmosphere. They are created by either aircraft exhaust or airflow over wingtip vortices as it emerges into cold temperatures at high altitudes and condenses into water and ice droplets. In this example a flurry of trails crisscrosses the sky creating an intricate pattern.

Rocket Exhaust Trails

Image by ilmungo

High altitude winds contort the trails of rockets and their small exhaust particles diffract sunlight into vivid iridescent colours, sometimes carried by the same winds thousands of kilometres before dissipating. The image shows the trails of the Minotaur rocket launched from the US Air Force Base at Vandenberg, California.

Sky Polarisation

Image by Philipp_Klinger

The sky, like many other things around us, scatters polarised light consisting of a certain electromagnetic orientation. Polarization is always perpendicular to the light path itself and if only a single polarization direction is present in the light, the light is said to be linearly polarized. This image was captured with a wide-angle polarised filter lens to show just how spectacular the electromagnetic charge of the skies are.

Star Trails

Image by Fort Photo

Not technically visible to the naked eye this breathtaking image was captured by leaving a camera with a shutter opening of over an hour at night. The natural rotation of the earth causes the stars in the sky to move across the horizon, creating these wonderful trails behind them. The only star in the night sky that appears stationary at all times is Polaris, the North Star, which hovers above the celestial North. The same would be true in the south but there is no star bright enough over it.

Zodiacal Light

Image by Alex Tudorica

A faint triangular glow seen in the night sky extending up towards the heavens, the Zodiacal light is easily masked by light pollution or moonlight. It is produced when sunlight reflects off dust particles in the cosmos, known as cosmic dust and consequently its spectrum is the same as the solar system. Solar radiation causes the dust particles to spiral slowly, creating a majestic constellation of delicately sprinkled lights in the sky.