The Rhythm of the Spheres

Reading the Night Sky

Wandering in Astronomy

The night sky is the oldest pattern of man, and every culture reads it differently. The stars above keep silent time, moving to a rhythm we are just now beginning to understand. Astronomy is where math, science, art, music, and words meet in a wondrous collision. In this section of our site, learn the basics of astronomy: from how a star chart is made, to projections and art that map the night sky, to how an astrolabe works just like it did thousands of years ago. Watch the North Star shift across centuries, explore how one sky has been mapped by many traditions, read what happened on this day in space, and see tonight’s moon for your location.

Map the Stars

The math behind star charts, with a projection explorer and a working astrolabe.

The Moving Sky

How the sky shifts across centuries, with a precession clock you can run.

The Traditions

One sky reads many ways, with a same-sky overlay of the world’s constellations.

This Day in the Stars

The sky’s events, discoveries, and lore tied to today’s date.

The Moon Tonight

Its phase and face, drawn live for where you’re standing.

✦  Astronomy Picture of the Day  ✦

A Rainbow Pileus Cloud over Zimbabwe

February 19, 2014
© Peter Lowenstein
Yes, but how many dark clouds have a multicolored lining? Pictured, behind this darker cloud, is a pileus iridescent cloud, a group of water droplets that have a uniformly similar size and so together diffract different colors of sunlight by different amounts. The above image was taken just before sunset when it was noticed by chance by a photographer in Murambi East, near Odzi Valley and the Mtanda Range of Zimbabwe. Also captured were unusual cloud ripples above the pileus cloud. The formation of a rare pileus cloud capping a common cumulus cloud is an indication that the lower cloud is expanding upward and might well develop into a storm. In this case, however, only a few minutes after the colorful cloud was noticed, it disappeared. Follow APOD on: Facebook (Daily) (Sky) (Spanish) (Arabic) or Google Plus (Daily)

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✦  EarthSky  ·  Astronomy.com  ·  Phys.org  ✦
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