
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.
The Spinning Pulsar of the Crab Nebula
Explore Your Universe: Random APOD Generator

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Euclid offers best-ever 3D map of the universe to date
The Euclid Consortium and the European Space Agency (ESA) have released the first major batch of data from the Euclid space telescope. This release, which captures light from more than a billion obโฆ
ReadNov. 12, 2014: The Philae lander touches down on a comet
The European Space Agencyโs Rosetta mission launched March 2, 2004, on a 4-billion-mile (6.4 billion kilometers) path to Comet 67P/Churyumov-Gerasimenko. The mission consisted of the Rosetta orbiโฆ
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 sunlโฆ
ReadVisible planets and night sky guide for November
Visible planets and night sky guide: Look west shortly after sunset to see earthshine on the crescent moon. And watch a video here about the Leonid meteors.
ReadโRosetta Stone for Mars:โ Martian meteorite hints at ancient life
A rare 4.1-billion-year-old Martian meteorite, Teghaza 001, provides new clues about Mars' ancient and more habitable past.
ReadIs there a North Star for Mars?
Is there a North Star for Mars ... a guide star for future explorers? Not in any satisfying way. But Martian stargazers wouldn't lack for things to see!
ReadThe Sky Today on Thursday, November 12: An open cluster in Perseus
Looking for a sky event this week? Check out our full Sky This Week column. November 11: Venus comes to a halt The constellation Perseus is famous for its bright Double Cluster, butโฆ
ReadIndependent technique validates landmark M87* image
The 2019 Event Horizon Telescope (EHT) image was the work of hundreds of scientists and captured the first direct view of a black hole's shadowโbecoming one of the most recognized scientific imagโฆ
ReadCentaurus A in the spotlight: Plasma simulations reproduce black hole jets' mysterious bright edges
Around 12 million light-years away, the supermassive black hole of the galaxy Centaurus A is hurling two enormous plasma jets into space at nearly the speed of light. These so-called jets are brighโฆ
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