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.
Hidden Galaxy IC 342
Customized Star Charts Coming 1st Quarter 2027
We respect your privacy. Unsubscribe at any time.
Sun news: Sun-blasts arrive with strike two
Sun news September 9, 2026: Strike two! A second CME sparked another G1 storm at 17:44 UTC. More are arriving today, so G2 storms and auroras are possible.
ReadThe Sky Today on Wednesday, September 9: Visualize the ecliptic
Looking for a sky event this week? Check out our full Sky This Week column. September 8: The Moon joins Jupiter The waning Moon has moved from Cancer to Leo and is nearing the brigh…
ReadOrion’s Belt points to Sirius on September mornings
Use Orion's Belt to find Sirius, the sky's brightest star. In 2026, Jupiter is in the same region, outshining even Sirius.
ReadSome black holes grow much faster than their galaxies
Nearly every galaxy has a supermassive black hole. The few that don't have had theirs ejected during a galactic collision. That's because galaxies and their black holes have formed hand in hand. Th…
ReadSpaceX closes out SES’s O3b mPower constellation
Rocket launches this week On Thursday, Sept. 10 at 5:00 a.m. EST, a Long March 2D rocket is set to lift off from Jiuquan Satellite Launch Center in northern China’s Gobi Desert carrying an undisc…
ReadExtremely massive galaxy proto-supercluster smashes distance record
An international team of astronomers has discovered the most distant progenitor to a galaxy supercluster ever. The discovery supports existing theories of how galaxy clusters evolve and reveals how…
ReadFast radio bursts could help disentangle galactic feedback from dark matter effects
Intense, brief flashes of radio light called fast radio bursts (FRBs) travel across billions of light-years to reach Earth, passing through a fog of matter along the way. The bursts' origins are un…
ReadSept. 8, 2016: OSIRIS-REx launches
On Sept. 8, 2016, the Origins, Spectral Interpretation, Resource Identification, and Security – Regolith Explorer (OSIRIS-REx) mission launched from Cape Canaveral, setting off on its 4.4-billion…
ReadHow many stars can you see on a moonless night?
Have you ever wondered how many stars are visible on a given night? It depends on factors including how dark your sky is and what your age is.
Read