
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.
Clouds in Cygnus

Customized Star Charts Coming 1st Quarter 2027
We respect your privacy. Unsubscribe at any time.
Giant mega-Earth is 23 times more massive than Earth
Astronomers have discovered a new giant mega-Earth exoplanet that is a whopping 23 times as massive as Earth, and 2.5 times the size.
ReadClawing through Cassiopeia
Luigi La Bella from Melilli, Italy The Lobster Claw Nebula (Sharpless 2-157) is a faint emission nebula straddling the constellations Cassiopeia and Cepheus. This complex of gas and dust has been s…
ReadHubble tracks new decagon encircling Saturn's south pole
Recent observations with NASA's Hubble Space Telescope have revealed a giant, evolving, 10-sided atmospheric wave encircling Saturn's south pole. This discovery marks the first time a large, regula…
ReadMicrobes may make it on the Moon
According to a new study, bacteria and fungi shed by humans could survive on the lunar surface for up to a week or longer. The study, published in Science Advances Aug. 19, paired microbiologists w…
ReadHawai'i high school students name image of glittering galaxy pair
Nā ʻUhane Māhoe Huki Pū i ke Ola is the Hawaiian name given to NGC 7253—a pair of spiral galaxies caught in each other's gravity. Captured by the Gemini North telescope on Maunakea in Hawai'i…
ReadSept. 2, 1859: The Carrington Event peaks
On Sept. 1, 1859, amateur astronomer Richard Carrington observed a massive eruption of bright light from the Sun’s surface. It was the first recorded observation of a solar flare. Within only 17.…
ReadMore than 120 molecular species found in giant cloud near Milky Way's center
Astronomers have discovered a second interstellar cloud near the center of the Milky Way that is extraordinarily rich in complex molecules, including several molecules associated with prebiotic che…
ReadVisible planets and night sky guide for September
Visible planets and night sky guide: Watch a livestream with Deborah Byrd today at noon CDT. Find out about 5 September sky sights you won’t want to miss!
ReadRoman space telescope has launched! You can adopt a pixel
The Nancy Grace Roman Space Telescope launched on August 30 from the Kennedy Space Center. Want to add your name to a pixel? Find out how here!
Read