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

NGC 4676: When Mice Collide

October 4, 2021
Credit: NASA , ESA, Hubble ; Processing & Copyright: William Ostling ( The Astronomy Enthusiast )
See this entry on NASA's APOD โ†’
These two mighty galaxies are pulling each other apart. Known as the โ€œ Mice โ€ because they have such long tails, each spiral galaxy has likely already passed through the other. The long tails are created by the relative difference between gravitational pulls on the near and far parts of each galaxy . Because the distances are so large, the cosmic interaction takes place in slow motion -- over hundreds of millions of years. NGC 4676 lies about 300 million light-years away toward the constellation of Bernice's Hair ( Coma Berenices ) and are likely members of the Coma Cluster of Galaxies . The featured picture was taken with the Hubble Space Telescope 's Advanced Camera for Surveys in 2002. These galactic mice will probably collide again and again over the next billion years so that, instead of continuing to pull each other apart, they coalesce to form a single galaxy .

Follow APOD in English on: Facebook , Instagram , or Twitter

Customized Star Charts Coming 1st Quarter 2027

We respect your privacy. Unsubscribe at any time.

โœฆ  EarthSky  ยท  Astronomy.com  ยท  Phys.org  โœฆ
Astronomy Nov 15, 2026

Is this iconic black hole image accurate? New study delivers an independent result

On April 10, 2019, the Event Horizon Telescope (EHT) Collaboration revealed the first picture of a black hole. The object is at the center of a galaxy known as M87, about 55 million light-years away.

Read
Astronomy Nov 14, 2026

A dead star is flashing radio waves every 8 minutes, and its partner looks a lot like the sun

Since 2022, astronomers have been puzzling over a new kind of cosmic object called long-period radio transients. These are objects that emit bright flashes of radio waves into space every few minutโ€ฆ

Read
Astronomy Nov 14, 2026

A cosmic magnifying glass could reveal the same supernova two more times in roughly 70 years

Thanks to the gravitational lensing caused by a massive galaxy cluster and high-resolution images from the James Webb Space Telescope (JWST), astronomers discovered an exploding star when the univeโ€ฆ

Read
Robotic Spaceflight Nov 14, 2026

Nov. 14, 2012: NASA announces an extended mission for Kepler

The Kepler Space Telescope, launched March 6, 2009, was designed to search the Milky Way for exoplanets. Using the transit method, Kepler ultimately observed over 500,00 stars and contributed to thโ€ฆ

Read
Sun Nov 14, 2026

Sun news: Hello, big newcomer sunspot!

Sun news November 14, 2026: Farewell, AR4566! A big new sunspot region is peeking over the sunโ€™s northeast edge and has already fired the top flare.

Read
Astronomy Essentials Nov 14, 2026

Visible planets and night sky guide for November

Visible planets and night sky guide: Tomorrow morning, look east for Jupiter and Mars at their closest on the sky's dome. They'll be just over a degree apart!

Read
Observing Nov 14, 2026

The Sky Today on Saturday, November 14: Venus and Mercury in Virgo

Looking for a sky event this week? Check out our fullย Sky This Weekย column.ย  November 13: Spot Mirachโ€™s Ghost Following inferior conjunction early this month, Mercury has reappeared in the morโ€ฆ

Read
What's Launching This Week Nov 13, 2026

How to watch Starship Flight 15

SpaceX is set to launch its 15th test flight of Starship on Friday, Nov. 13. For the first time, the company will try to catch both stages of the rocket โ€” the Super Heavy booster and the upper stโ€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