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  ✦

The Seagull Nebula

January 11, 2014
© Michael Miller
A broad expanse of glowing gas and dust presents a bird-like visage to astronomers from planet Earth, suggesting its popular moniker - The Seagull Nebula. This portrait of the cosmic bird covers a 1.6 degree wide swath across the plane of the Milky Way, near the direction of Sirius, alpha star of the constellation Canis Major. Of course, the region includes objects with other catalog designations: notably NGC 2327, a compact, dusty emission region with an embedded massive star that forms the bird's head (aka the Parrot Nebula, above center). Dominated by the reddish glow of atomic hydrogen, the complex of gas and dust clouds with bright young stars spans over 100 light-years at an estimated 3,800 light-year distance.

Customized Star Charts Coming 1st Quarter 2027

We respect your privacy. Unsubscribe at any time.

✦  EarthSky  ·  Astronomy.com  ·  Phys.org  ✦
Today's Image Sep 24, 2026

The red planet shows strange swirls of purple and pink

Mars Express captured this view of the red planet showing it in less familiar purple, pink and blue shades. Read why the red planet looks purplish.

Read
Space Sep 24, 2026

Curiosity rover insights after 5000+ sols on Mars

Curiosity rover has now spent 5,000 sols — the equivalent to 5,000 Martian days, or more than 14 years — on Mars. Here's a look at some of its discoveries.

Read
Earth Sep 24, 2026

Would a Yellowstone supervolcano eruption end humanity now?

Yellowstone has undergone 3 massive super-eruptions in the past. If the Yellowstone supervolcano erupted today, would humanity survive?

Read
Observing Sep 24, 2026

The Sky Today on Thursday, September 24: Blue Neptune, yellow star

Looking for a sky event this week? Check out our full Sky This Week column.  September 23: Around Reiner Gamma Neptune stands close to a slightly fainter background star this evening…

Read
Astronomy Sep 23, 2026

Astrophysicists use wave simulations to open a new window on dark matter

Astrophysicists from The University of Hong Kong (HKU), working with a research team led by Beijing Normal University (BNU), have developed a more physically realistic approach to testing how ultra…

Read
Astronomy Sep 23, 2026

NASA's Hubble seeks lensed supernova, marks 200,000 orbits

NASA's Hubble Space Telescope completed its 200,000th orbit around Earth on Sept. 19, marking another milestone for an observatory that continues to transform our understanding of the universe.

Read
Sep 23, 2026

A wind-blown crescent

Aloke Palsikar, taken from Pie Town, New Mexico The Crescent Nebula (NGC 6888) is an emission nebula about 5,600 light-years away in Cygnus. Its distinctive shape was formed by fast stellar winds f…

Read
Features Sep 23, 2026

Finding light’s true nature

Light exhibits some of the strangest properties in our cosmos. It manifests as both a wave and a particle, and its speed in a vacuum is invariant. While physicists now fully grasp the way light int…

Read