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.

✦  Astronomy Picture of the Day  ✦

Ringside with Rhea

March 29, 2013
Orbiting in the plane of Saturn's rings, Saturnian moons have a perpetual ringside view of the gas giant planet. Of course, while passing near the ring plane the Cassini spacecraft also shares their stunning perspective. The thin rings themselves slice across the middle of this Cassini snapshot from April 2011. The scene looks toward the dark night side of Saturn, in the frame at the left, and the still sunlit side of the rings from just above the ringplane. Centered, over 1,500 kilometers across, Rhea is Saturn's second largest moon and is closest to the spacecraft, around 2.2 million kilometers away. To Rhea's right, shiny, 500 kilometer diameter Enceladus is about 3 million kilometers distant. Dione, 1,100 kilometers wide, is 3.1 million kilometers from Cassini's camera on the left, partly blocked by Saturn's night side.

Customized Star Charts Coming 1st Quarter 2027

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✦  EarthSky  ·  Astronomy.com  ·  Phys.org  ✦
Observing Aug 28, 2026

The Sky Today on Friday, August 28: Vesta stands still

Looking for a sky event this week? Check out our full Sky This Week column.  August 27: A deep partial lunar eclipse Asteroid 9 Metis reaches opposition at 10 A.M. EDT. It is in the …

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Sky This Week Aug 28, 2026

The Sky This Week from August 28 to September 4: Venus and Spica meet

Friday, August 28Friday opens with a deep partial lunar eclipse — the Full Moon occurs at 12:19 A.M. EDT, just six minutes after the event reaches maximum eclipse. August’s Sturgeon Moon will a…

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Observing Aug 27, 2026

2026 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…

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Astronomy Aug 27, 2026

ASTRID traces 13.5 billion years of black hole and galaxy evolution

In dark skies at night, distant starlight twinkles and speaks to vast cosmic histories almost as old as time itself. New data from instruments such as NASA's James Webb Space Telescope are helping …

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Astronomy Aug 27, 2026

Milky Way's own gravity can mimic dark matter clues, stellar stream simulations suggest

Most of the stars in our Milky Way galaxy sit neatly on a flat plane. But the space around our galaxy is much more chaotic. Rogue bands of stars called "stellar streams" orbit the Milky Way much li…

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Astronomy Aug 27, 2026

NASA's Webb telescope rules out two new Dyson sphere candidates

The latest Swedish-led search for technosignatures in the form of Dyson spheres has again come up empty-handed. The two latest stellar candidates in the hunt for such hypothetical extraterrestrial …

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Astronomy Essentials Aug 27, 2026

Deep partial lunar eclipse overnight tonight!

A deep partial lunar eclipse of the full Sturgeon Moon takes place on August 27-28, 2026. Will you be able to see it? Maps and details here.

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Sun Aug 27, 2026

Sun news: Auroras to pair with the eclipse tonight?

Sun news August 27, 2026: The M7 flare's sun-stuff arrives tomorrow. G2 storms are possible, and fast solar wind could spark auroras as early as tonight!

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Earth Aug 27, 2026

Nepal flash flood nightmare: What caused it?

On August 26, 2026, a glacier collapse and landslide triggered a huge release of water. The Nepal flash flood wiped out villages and took untold lives.

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