Luminous pillar (light pillar)

(Section 3.2.3.1.3)

A white luminous pillar, appearing as a broken or continuous trail of light and also known as a light pillar, may be observed vertically above and below a light source, such as the Sun or Moon. Light pillars may occasionally be observed above terrestrial light sources, and on rare occasions, small light pillars may be seen extending above and/or below a bright planet, such as Venus. When the Sun is the light source, the phenomenon is known as a Sun pillar. A pillar above the light source is an upper pillar, and below the light source is a lower pillar. Lower pillars are best seen from a hill or mountain, or an aircraft, when there is ice cloud, freezing fog or ice crystals such as diamond dust below.