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.
A Hole in Mars
Customized Star Charts Coming 1st Quarter 2027
We respect your privacy. Unsubscribe at any time.
Black holes from stellar to supermassive size may follow one jet-launching rule
An early-career Western Australian astrophysicist has helped uncover a universal rule behind one of the most powerful behaviors in the universe: when black holes launch jets. The discovery, publish…
Read2026 Full Moon calendar: When to see the Full Moon and phases
The phenomenon of a Full Moon arises when our planet, Earth, is precisely sandwiched between the Sun and the Moon. This alignment ensures the entire side of the Moon that faces us gleams under sunl…
ReadSept. 17, 1789: William Herschel discovers Mimas
With 293 confirmed moons as of August of 2026, Saturn is the solar system planet with the most natural satellites. By 1789, though, only five had been spotted: Titan by Christiaan Huygens in 1655, …
ReadDiamond in the sky
Dave Doctor from Las Cruces, New Mexico The diamond ring at third contact during the Aug. 12, 2026, total solar eclipse hangs over Alcañiz, Spain, as the Moon’s shadow floods the left side of th…
ReadHuge new Webb image is chock-full of space delights
ESA has unveiled a spectacular new Webb image. One of the largest shots yet, it features protostars, jets, distant spiral galaxies and a gravitational lens.
Read1st adult T. rex trackway found by high school teacher
A high school teacher discovered 4 footprints that make up the 1st-ever known T. rex trackway. He discovered it at Hell Creek Formation in North Dakota.
ReadVisible planets and night sky guide for September
Visible planets and night sky guide: Look for the waxing crescent moon near red Antares this evening. And see a video explaining the equinox.
ReadMuon rings enable precise calibration of telescopes at the Cherenkov Telescope Array Observatory
Research initiated as part of a bachelor's thesis in physics at the Universitat Autònoma de Barcelona (UAB) has culminated in a new analytical description of the muon-based calibration of dual-mir…
ReadNearly 50 'ghost galaxies' emerge around three hosts, challenging dwarf galaxy counts
Dwarf galaxies—with a mass equal to about a billion suns, but often considerably less—are the most abundant in the universe. However, because of their low luminosity, they are very difficult to…
Read