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  ✦

Mt. Hood and a Lenticular Cloud

April 17, 2013
© Ben Canales
What kind of cloud is next to that mountain? A lenticular. This type of cloud forms in air that passes over a mountain, rises up again, and cools past the dew point -- so what molecular water carried in the air condenses into droplets. The layered nature of some lenticular clouds may make them appear, to some, as large alien spaceships. In this case, the mountain pictured is Mt. Hood located in Oregon, USA. Lenticular clouds can only form when conditions are right -- for example this is first time this astrophotographer has seen a lenticular cloud at night near Mt. Hood. The above image was taken in mid-March about two hours before dawn.

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✦  EarthSky  ·  Astronomy.com  ·  Phys.org  ✦
Observing Aug 30, 2026

The Sky Today on Sunday, August 30: The Moon, Neptune, and Saturn

Looking for a sky event this week? Check out our full Sky This Week column.  August 29: Double star Zeta Lyrae The waxing Moon passes 5° north of Neptune at 9 A.M. EDT. Although bot…

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Constellations Aug 30, 2026

Telescopium the Telescope is below the Teapot

Telescopium the Telescope is a constellation that appears best in southern skies, south of the Teapot. Look for it in dark skies.

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Today in the History of Astronomy Aug 29, 2026

Aug. 29, 1990: Hubble sees Supernova 1987A clearly

The first light from the explosion that was the death of a massive star in the nearby Large Magellanic Cloud reached Earth on Feb. 23, 1987. Supernova 1987A’s proximity gave astronomers unprecede…

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Astronomy Essentials Aug 29, 2026

Visible planets and night sky guide for August and September

Visible planets and night sky guide: Tonight's moon is near Saturn. Plus Jupiter is returning at dawn. And a new 'this week's sky' video is out.

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Sun Aug 29, 2026

Sun news: Chunk of solar stuff delayed. Maybe today

Sun news August 29, 2026: The chunk of solar stuff from the M7 flare is running late. Arrival today. G2 storms and auroras are possible tonight!

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Observing Aug 29, 2026

The Sky Today on Saturday, August 29: Double star Zeta Lyrae

Looking for a sky event this week? Check out our full Sky This Week column.  August 28: Vesta stands still You may have heard of Epsilon (ε) Lyrae, the famous Double Double star in the constell…

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Astronomy Aug 28, 2026

NASA telescope honors Nancy Grace Roman, architect of space-based astronomy

The Nancy Grace Roman Space Telescope is set to launch this weekend aboard a SpaceX rocket from Kennedy Space Center in Florida. When it becomes operational early next year, it will transform our v…

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Astronomy Aug 28, 2026

Will new telescope Roman help reveal long-kept secrets of the universe? Q&A with an expert

On Sunday, Aug. 30, the Nancy Grace Roman Space Telescope is expected to launch from NASA's Kennedy Space Center in Florida. The observatory will join the Hubble Space Telescope, launched in 1990, …

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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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