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  ✦

Andromeda on the Rocks

September 27, 2013
© Cristian Fattinnanzi
How far can you see? The Andromeda Galaxy 2.5 million light years away is the most distant object easily seen by the unaided eye. Other apparent denizens of the night sky, stars, clusters, and nebulae, typically range from a few hundred to a few thousand light-years away and lie well within our own Milky Way Galaxy. Also known as M31, the Andromeda Galaxy is the faint smudge near top center of this Earth and skyscape, taken from eastern Italy, near Monte Conero on the Adriatic sea coast. From a few centimeters to a few million light-years, the picture demonstrates a stunning range of vision. Though galaxy and seaside rocks could be seen with the eye on that clear summer night, no camera captured this view in a single exposure. Because the stars trailed above the horizon while the picture was made, separate exposures tracking the stars were combined with one of rocks and cliffs made with the camera steadied to create the tantalizing scene.

Customized Star Charts Coming 1st Quarter 2027

We respect your privacy. Unsubscribe at any time.

✦  EarthSky  ·  Astronomy.com  ·  Phys.org  ✦
Astronomy Sep 14, 2026

Active black holes reveal star-forming rings and shock waves in nine nearby galaxies

A new study of nine nearby galaxies has shown that actively growing supermassive black holes may contribute to, rather than prevent, star formation in their host galaxies.

Read
What's Launching This Week Sep 14, 2026

Europe launches two Earth-observation satellites amidst a busy week for China

Rocket launches this week On Monday, Sept. 14 at 9:21 p.m. EST, Avio — a publicly traded Italian aerospace company headquartered near Rome — is set to launch a Vega C rocket from the Guiana Spa…

Read
Astronomy Sep 14, 2026

Physicists zoom into the birth of cosmic rainstorms with new CERN study

Every second, particles zip through your body at nearly the speed of light. They rain down from a storm high in the sky, where cosmic rays, a powerful type of interstellar matter, constantly strike…

Read
Telescopes and Equipment Sep 14, 2026

Sept. 14, 1915: The birth of John Dobson

On Sept. 14, 1915, John Dobson was born in Bejing. His family moved to San Francisco to avoid political turmoil in China in 1927, and Dobson went on to attend the University of California, Berkeley…

Read
Galaxies Sep 14, 2026

Why do bars form in some spiral galaxies, but not in others?

Why do bars form in some spiral galaxies, but not in others? Joe RuszHerndon, VA We believe that stellar bars can form in any galaxy that displays ordered rotation. This includes galaxies with disk…

Read
Astronomy Sep 14, 2026

Bizarre galactic radio source remains active for two decades with no detectable X-rays

Astronomers have identified a peculiar radio transient in the Milky Way that has remained active for more than two decades, defying the behavior expected of known classes of galactic radio sources.…

Read
Astronomy Essentials Sep 14, 2026

Visible planets and night sky guide for September

Visible planets and night sky guide: Venus reaches its brightest in the sky this week. Don't miss it near the thin moon tonight.

Read
Sun Sep 14, 2026

Sun news: Violent filament eruption last night

Sun news September 14, 2026: A violent filament eruption sent plasma into space. Initial analysis suggests a glancing blow at Earth on September 17.

Read
Astronomy Essentials Sep 13, 2026

Venus brightest in the evening sky this week

See Venus brightest in the evening sky this week, with greatest brilliancy coming around September 18, 2026. Look west after sunset.

Read