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

Tails of Comet Wierzchoล›

February 17, 2026
Credit: Josรฉ J. Chambรณ ; Text: Cecilia Chirenti ( NASA GSFC , UMCP , CRESST II )
See this entry on NASA's APOD โ†’
Some comets are regular guests of our solar neighborhood; others come by only once, never to return. We wonโ€™t have another chance to see Comet C/2024 E1 (Wierzchoล› ), which is currently making its way through the inner Solar System . The hyperbolic orbit of this comet indicates that it will likely become an interstellar traveler. Comet Wierzchoล› is today near its closest approach to the Earth, passing roughly the same distance from the Earth as is the Sun . The featured 30-minute exposure was taken last week in Chile and shows a 5-degree long ion tail as well as three shorter dust tails . The green hue of the coma comes from the breakdown of dicarbon molecules by sunlight, but that process does not last long enough to also tinge the tails . On the far right lies a spiral galaxy far in the distance: NGC 300 .

Customized Star Charts Coming 1st Quarter 2027

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โœฆ  EarthSky  ยท  Astronomy.com  ยท  Phys.org  โœฆ
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