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

Blue Ghost's Diamond Ring

March 19, 2025
Credit: Firefly Aerospace
See this entry on NASA's APOD โ†’
On March 14 the Full Moon slid through Earth's dark umbral shadow and denizens of planet Earth were treated to a total lunar eclipse . Of course, from the Moon's near side that same astronomical syzygy was seen as a solar eclipse. Operating in the Mare Crisium on the lunar surface , the Blue Ghost lander captured this video frame of Earth in silhouette around 3:30am CDT, just as the Sun was emerging from behind the terrestrial disk. From Blue Ghost's lunar perspective the beautiful diamond ring effect, familiar to earthbound solar eclipse watchers, is striking. Since Earth appears about four times the apparent size of the Sun from the lunar surface the inner solar corona , the atmosphere of the Sun most easily seen from Earth during a total solar eclipse, is hidden from view. Still, scattering in Earth's dense atmosphere creates the glowing band of sunlight embracing our fair planet .

Customized Star Charts Coming 1st Quarter 2027

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โœฆ  EarthSky  ยท  Astronomy.com  ยท  Phys.org  โœฆ
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