Observing Projects

Atmospheric Optical Phenomenon

Atmospheric Optical PhenomenonAtmospheric Optical Phenomenon cover a wide range of interesting sights that can be seen in the sky on many days throughout the year. Since becoming interested in astronomy I have also learnt more about these strange and usually beautiful sights and have tried to capture them on camera when possible. This page shows the highlights of the photos, more of which can be seen in my gallery on Flickr. These photos were taken by myself between 2006 and 2007 with a Pentax Optio 33lf and a Panasonic DMC-FZ7.

You might also be interested in Martin Mckenna's Atmospherics Gallery.


The classic and most widely recognised optical phenomenon, rainbows require sunshine and rain and appear opposite to the sun in the sky. They are caused by sunlight being reflected back from spherical drops of rain, causing a bright spectrum to be seen.

Rainbow over Lake Wakatipu, Otago, New Zealand A Rainbow Rainbow in the West, Abel Tasman National Park, New Zealand

Resources: Wikipedia · AtOptics

Sun Dogs

A sun dog (or parhelion) is one of the most common types of halo associated with the refraction of sunlight by small hexagonal prism shaped ice crystals. They usually appear close to sunrise or sunset when faint cirrus or cirrostratus clouds have built up and are located on the circle of the 22° halo but move out as the sun rises.

Southern Sundog Northern Sundog The Balloon, The Sundog, The Sun and some Trees A Sun Dog Strikes a Cloud A Sun Dog Panorama with Sundogs Northern Sundog Sun Dog Sun Dog

Resources: Wikipedia · AtOptics

Crepuscular Rays

These are rays that appear to radiate from a single point in the sky and are caused by sunlight streaming through gaps in clouds. They are usually most visible around sunrise or sunset and are so pronounced because of the effects of scattering and diffraction.

Crepuscular Rays Sunset with Crepuscular Rays Big Skies, North Yorkshire Crepuscular Rays P1070131 Crepuscular Rays Rays P1070705 Crepuscular Rays Rays over Butler College, Durham

Crepuscular Rays

Resources: Wikipedia · AtOptics

Anticrepuscular Rays

These are similar to crepuscular rays, but are seen opposite the sun in the sky as the straight line rays converge on the anti-solar point. They are usually dimmer than crepuscular rays.


Resources: Wikipedia · AtOptics

Solar Halos

One of the most common types of phenomenon, these halos are visible anytime there is hazy, thin cirrus clouds in the sky whcih are formed from tiny, uniform ice crystals.

Solar Halo Solar Halo

Resources: AtOptics

Solar Pillars

These appear when the sun is close to the horizon and are the result of light glinting off millions of ice crystals to form a narrow, seeimgly vertical pillar extending from the sun by 5-10º.

A Bit of a Sun Pillar Solar Pillar

Resources: AtOptics

Iridescent Clouds

These are thin clouds which are formed from very similar sized droplets such that diffraction of sunlight through them makes them shine with colours like a corona. They are usually found close to the sun (hide it behind a building) and appear most often in newly forming altocumulus, cirrocumulus and lenticular clouds.

Mystery Iridescent Clouds

Resources: Wikipedia · AtOptics