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  ✦

Journey to the Center of the Galaxy

July 2, 2012
What wonders lie at the center of our Galaxy? In Jules Verne's science fiction classic A Journey to the Center of the Earth, Professor Liedenbrock and his fellow explorers encounter many strange and exciting wonders. Astronomers already know of some of the bizarre objects that exist at our Galactic center, including like vast cosmic dust clouds, bright star clusters, swirling rings of gas, and even a supermassive black hole. Much of the Galactic Center is shielded from our view in visible light by the intervening dust and gas, but it can be explored using other forms of electromagnetic radiation. The above video is actually a digital zoom into the Milky Way's center which starts by utilizing visible light images from the Digitized Sky Survey. As the movie proceeds, the light shown shifts to dust-penetrating infrared and highlights gas clouds that were recently discovered to be falling toward central black hole. Poll: When I couldn't find APOD online I thought that . . . Note: APOD back after unexpected power outage

Customized Star Charts Coming 1st Quarter 2027

We respect your privacy. Unsubscribe at any time.

✦  EarthSky  ·  Astronomy.com  ·  Phys.org  ✦
Favorite Star Patterns Sep 20, 2026

Great Square of Pegasus gallops into the autumn sky

The Great Square of Pegasus consists of 4 stars of nearly equal brightness in a large square pattern. It's a great jumping-off point for star-hopping.

Read
Observing Sep 20, 2026

The Sky Today on Sunday, September 20: Juno’s movement

Looking for a sky event this week? Check out our full Sky This Week column.  September 19: Mars meets Pollux Now is the best time to catch 145-mile-wide 3 Juno as it passes through a…

Read
Tonight Sep 20, 2026

The equinox sun rises due east and sets due west

The 2026 September equinox occurs at 00:05 UTC on September 23, 2026. And the equinox sun rises and sets due east and due west.

Read
Today in the History of Astronomy Sep 19, 2026

Sept. 19, 1959: A SETI kickstart

On Sept. 19, 1959, the paper “Searching for Interstellar Communications” was published. Printed in the respected scientific journal Nature and written by Cornell University physicists Giuseppe …

Read
Earth Sep 19, 2026

Scientists discover a new tiger cat hiding in plain sight

Scientists studying the tiger cat have found 5 distinct species, revealing more diversity among these familiar-looking wild cats than previously known.

Read
Observing Sep 19, 2026

The Sky Today on Saturday, September 19: Mars meets Pollux

Looking for a sky event this week? Check out our full Sky This Week column.  September 18: The Lizard’s brightest cluster Mars passed 6° due south of Pollux in Gemini at midnight …

Read
Astronomy Sep 18, 2026

Hubble spots an out-of-sync galaxy

Though the spiral galaxy in this new image from the NASA/ESA Hubble Space Telescope seems serene, it hides a chaotic secret. This galaxy is NGC 4698, and it lies about 55 million light-years away i…

Read
Astronomy Sep 18, 2026

From the start, the solar system chose fire over ice to build its first bodies

When the solar system first took up the task of building solid bodies—such as planets, moons and protoplanets—it basically had a choice between two ingredients: heat-forged chondrules, which we…

Read
Astronomy Sep 18, 2026

Time is running out to catch a giant planet's strange orbit

A team of researchers, including those from the University of Tokyo, spotted a rare kind of planet that's unusually hot and eccentric. TOI-1355 b orbits its star, TOI-1355, which is also much hotte…

Read