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

A Year in Sunsets

December 21, 2024
Credit: Wael Omar
See this entry on NASA's APOD โ†’
A year in sunsets, from April 2023 to March 2024, track along the western horizon in these stacked panoramic views. The well-planned sequence is constructed of images recorded near the 21st day of the indicated month from the same location overlooking Cairo, Egypt. But for any location on planet Earth the yearly extreme northern (picture right) and southern limits of the setting Sun mark the solstice days. The word solstice is from Latin for โ€œSunโ€ and โ€œstand stillโ€. On the solstice date the seasonal drift of the Sun's daily path through the sky appears to pause and reverse direction in its annual celestial journey . Of course the Sun reaches a stand still on today's date. The 21 December 2024 solstice at 09:21 UTC is the moment of the Sun's southernmost declination, the start of astronomical winter in the north and summer in the south .

Customized Star Charts Coming 1st Quarter 2027

We respect your privacy. Unsubscribe at any time.

โœฆ  EarthSky  ยท  Astronomy.com  ยท  Phys.org  โœฆ
Robotic Spaceflight Nov 13, 2026

Nov. 13, 1971: Mariner 9 orbits Mars

On May 30, 1971, Mariner 9 launched, setting off on its mission to Mars. On Nov. 13, 167 days later, it entered orbit around Mars, making it the first spacecraft to orbit another planet. With Marinโ€ฆ

Read
Observing Nov 13, 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 sunlโ€ฆ

Read
Astronomy Nov 13, 2026

Euclid's first data release: A stepping stone to its 3D map of the sky

The ESA's Euclid has already teased us with some early results. In the past, it's given us a small image covering 60 square degrees of the sky, created with a few days of observations. Those imagesโ€ฆ

Read
Space Nov 13, 2026

Mountain-sized asteroid 1999 AN10 to pass close to Earth in 2027

Asteroid 1999 AN10, which might be a mile wide, will pass Earth on August 7, 2027, about 1 lunar distance away. The encounter poses no danger.

Read
Sun Nov 13, 2026

Sun news: How the sun stripped Mars of its air

Sun news November 13, 2026: A year ago, the ESCAPDE spacecraft launched toward Mars. And this mission will also be monitoring the sun.

Read
Astronomy Essentials Nov 13, 2026

Mirach is your guide star to finding 3 galaxies

Mirach in the constellation Andromeda helps stargazers locate the Andromeda Galaxy, the Triangulum Galaxy, and "Mirach's Ghost."

Read
Observing Nov 13, 2026

The Sky Today on Friday, November 13: Spot Mirachโ€™s Ghost

Looking for a sky event this week? Check out our full Sky This Week column.  November 12: An open cluster in Perseus Celebrate Friday the 13th with something spooky: a ghost in the cโ€ฆ

Read
Astronomy Nov 12, 2026

Hubble offers cosmic sampler of targets for Roman

A gallery of gravitational lenses captured by NASA's Hubble Space Telescope showcases the diversity of this cosmic phenomenon and lays the groundwork for follow-up observations by the new Nancy Graโ€ฆ

Read
Astronomy Nov 12, 2026

Space telescope Euclid sets the new standard for cosmology

On July 1, 2023, the European Space Agency (ESA) launched the Euclid space telescope into space. Its mission: to create the largest and most detailed map of the universe ever made.

Read