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.

โœฆ  Astronomy Picture of the Day  โœฆ

Shadow of a Martian Robot

June 5, 2024
Credit: NASA , JPL-Caltech , MSSS , ASU , NeV-T, Perseverance Rover ; Processing & Copyright: Neville Thompson , Gigapan Zoom
See this entry on NASA's APOD โ†’
What if you saw your shadow on Mars and it wasn't human? Then you might be the Perseverance rover exploring Mars . Perseverance has been examining the Red Planet since 2021, finding evidence of its complex history of volcanism and ancient flowing water , and sending breathtaking images across the inner Solar System . Pictured here in February of 2024, Perseverance looks opposite the Sun and across Neretva Vallis in Jezero Crater , with a local hill visible at the top of the frame. The distinctively non-human shadow of the car-sized rover is visible below center, superposed on scattered rocks . Perseverance, now working without its flying companion Ingenuity , continues to search Mars for signs of ancient life .

Customized Star Charts Coming 1st Quarter 2027

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โœฆ  EarthSky  ยท  Astronomy.com  ยท  Phys.org  โœฆ
Astronomy Oct 28, 2026

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Observing Oct 28, 2026

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