A Sun Halo Over Tennessee
9.03.2005

Sometimes it looks like the Sun is being viewed through a large lens. In the above case, however, there are actually millions of lenses: ice crystals. As water freezes in the upper atmosphere, small, flat, six-sided, ice crystals might be formed.

A Sun Pillar
6.07.1999

Have you ever seen a sun pillar? When the air is cold and the Sun is rising or setting, falling ice crystals can reflect sunlight and create an unusual column of light. Ice sometimes forms flat, stop-sign shaped crystals as it falls from high-level clouds.

Moon Halo over Stone Circle
2.05.2018

Have you ever seen a halo around the Moon? This fairly common sight occurs when high thin clouds containing millions of tiny ice crystals cover much of the sky. Each ice crystal acts like a miniature lens.

Light Pillars over Alaska
8.02.2016

What's happening behind those houses? Pictured here are not auroras but nearby light pillars, a nearby phenomenon that can appear as a distant one. In most places on Earth, a lucky viewer...

An Avalanche on Mars
11.03.2008

What caused this sudden cloud of dust on Mars? An avalanche! The first avalanche imaged in progress on another planet was recorded last month on Mars by NASA's robotic Mars Reconnaissance Orbiter. Visible...

A Halo Around the Moon
21.04.2003

Have you ever seen a halo around the Moon? This fairly common sight occurs when high thin clouds containing millions of tiny ice crystals cover much of the sky. Each ice crystal acts like a miniature lens.

Unusual Light Patch Under Phoenix Lander on Mars
2.06.2008

Is that ice under the Phoenix spacecraft on Mars? Quite possibly. Phoenix, which landed a week ago, was expected to dig under the Martian soil to search for ice, but the lander's breaking jets may already have uncovered some during descent.

A Halo Around the Moon
15.05.2000

Have you ever seen a halo around the Moon? This fairly common sight occurs when high thin clouds containing millions of tiny ice crystals cover much of the sky. Each ice crystal acts like a miniature lens.

A Sun Halo Over Cambodia
8.02.2010

Have you ever seen a halo around the Sun? This fairly common sight occurs when high thin clouds containing millions of tiny ice crystals cover much of the sky. Each ice crystal acts like a miniature lens.

A Halo Around the Moon
7.12.2008

Have you ever seen a halo around the Moon? This fairly common sight occurs when high thin clouds containing millions of tiny ice crystals cover much of the sky. Each ice crystal acts like a miniature lens.