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

AR 3664: Giant Sunspot Group

May 11, 2024
Credit: Franco Fantasia & Guiseppe Conzo ( Gruppo Astrofili Palidoro )
See this entry on NASA's APOD โ†’
Right now, one of the largest sunspot groups in recent history is crossing the Sun. Active Region 3664 is not only big -- it's violent, throwing off clouds of particles into the Solar System . Some of these CME s are already impacting the Earth, and others might follow. At the extreme, these solar storms could cause some Earth-orbiting satellites to malfunction , the Earth's atmosphere to slightly distort, and electrical power grids to surge . When impacting Earth's upper atmosphere , these particles can produce beautiful auroras, with some auroras already being reported unusually far south . Pictured here, AR3664 and its dark sunspot s were captured yesterday in visible light from Rome , Italy . The AR3664 sunspot group is so large that it is visible just with glasses designed to view last month's total solar eclipse . This weekend, skygazing enthusiasts will be keenly watching the night skies all over the globe for bright and unusual auroras .

Gallery: Active Region 3664 on the Sun and Associated Aurora

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โœฆ  EarthSky  ยท  Astronomy.com  ยท  Phys.org  โœฆ
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