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.
NGC 2683: Edge-On Spiral Galaxy
Customized Star Charts Coming 1st Quarter 2027
We respect your privacy. Unsubscribe at any time.
Sun news: Quiet sun returns as coronal hole influence fades
Sun news September 28, 2026: The coronal hole stream has faded, and the sun stayed quiet with only small C flares. Calm conditions should hold for days.
ReadVisible planets and night sky guide late September and October
Visible planets and night sky guide. Tonight, look for the bright waning gibbous moon near planet Saturn and the Pleiades star cluster.
ReadThe Sky Today on Monday, September 28: Open cluster M39 shines
Looking for a sky event this week? Check out our full Sky This Week column. September 27: Catch Saturn’s satellites Although the Moon still dominates much of the night, bright dee…
ReadAstronomers discover a radio galaxy with evidence of four separate jet outbursts
Astronomers have identified what may be the first example of a new class of radio galaxy, one whose central black hole appears to have launched powerful jets on four separate occasions. High-resolu…
ReadSept. 27, 1918: The birth of Martin Ryle
Born Sept. 27, 1918, and educated at Bradfield College and Oxford University in the U.K., Martin Ryle would go on to be the first astronomer royal (1972-1982) with a background in radio astronomy. …
ReadJUICE mission to fly by Earth Monday: Details here
The JUICE mission will perform a flyby of Earth next week on September 28. The spacecraft is headed toward Jupiter's icy moons, where it will arrive in 2031.
ReadThe Sky Today on Sunday, September 27: Catch Saturn’s satellites
Looking for a sky event this week? Check out our full Sky This Week column. September 26: The Harvest Moon The Moon now passes 7° north of Saturn at 8 A.M. EDT. The ringed planet c…
ReadBlack hole jets reach far beyond galaxies' visible edges, potentially deciding their fate
Galaxies are enormous and hold hundreds of billions of stars. These stars form from cold, dense gas. Every large galaxy, including the Milky Way, is wrapped in a huge envelope of gas called the cir…
ReadAn overlooked era of cosmology is stealing the show in the quest to understand the cosmos
Could you imagine if pagers made a comeback? Sure, your smartphone would still be your notepad-flashlight-camera-personal assistant-MP3 player-wallet-social media browser. But imagine if pagers mad…
Read