Dense star field with Milky Way and several bright stars behind a domed observatory building.

Beta Centauri is a Southern Pointer Star

Beta Centauri isn’t as famous as Alpha Centauri, but together, these brilliant Southern Hemisphere stars have inspired legends and guided mariners.

What appears to be a densely populated star field with tiny oblong smudges.

The Coma Cluster contains thousands of galaxies

Myriads of galaxies, visible only to those with medium-to-large telescopes, shine among the stars in the “Realm of the Galaxies.” Study of the Coma Cluster of galaxies aided in the discovery of dark matter.

Poster for International Dark Sky Week.

International Dark Sky Week is April 5 to 12

Celebrate dark night skies and help limit light pollution by raising awareness through the annual International Dark Sky Week, April 5 to 12, 2021. Find links to global events here.

April 2021 guide to the bright planets

April 2021 showcases 3 bright planets. Mars is the only easy-to-see bright planet in the evening sky. Jupiter and Saturn adorn the early morning hours. Mercury and Venus hover too close to the sun’s glare for easy viewing.

JUpiter's four major moons: Io, Europa, Ganymede and Callisto.

Jupiter’s equinox and mutual events of its 4 major moons

The king planet Jupiter reaches its equinox on May 2, 2021, an event that always causes mutual events of Jupiter’s 4 major moons. It’s an eclipse season of the moons.

Basket of eggs with brightly colored, intricate designs painted on them.

When is Easter in 2021?

In 2021, Easter Sunday will fall on April 4. How the date of Easter is determined, here.

A smaller full moon superimposed on a larger crescent moon.

Is March’s full moon a supermoon?

The full moon on March 28, 2021, ranks as the 4th-closest (and therefore 4th-largest and 4th-brightest) of the 12 full moons of 2021. Is it a supermoon? Here’s why experts disagree.

Simulated solar system orbits, showing the location of the Earth and the asteroid on January 6, 2021.

2001 FO32: Big asteroid sweeps closest this weekend

When the asteroid labeled 2001 FO32 sweeps closest to Earth on March 21, 2021, it’ll be moving at such a fast pace that observers using telescopes might be able to detect its motion – its drift in front of the stars – in real time. Charts and info here.

Three curved, dotted sun tracks across the sky from various heights above the horizon down to the horizon.

All you need to know: March equinox 2021

Spring begins in the Northern Hemisphere at the equinox on March 20, 2021, at 09:37 UTC. At the same moment, the Southern Hemisphere enters the autumn season.

Equal day and night on the equinox?

There is more daylight than nighttime on the day of the equinox, an additional 8 or so minutes of daylight at mid-temperate latitudes.

Pyramid-shaped hazy band of zodiacal light, next to a bright section of the starry Milky Way.

It’s time to watch for the zodiacal light

The zodiacal light is an eerie light extending up from the horizon. This is a good time of the year to see it in the evening from the Northern Hemisphere. Southern Hemisphere, look before dawn!

Earth globe centered on North America, with yellow ribbons wrapped around its surface labeled with dates.

When is the next total solar eclipse in North America?

Did you see the awe-inspiring total solar eclipse of August 21, 2017? Millions across North America witnessed it. When and where will the next North American total solar eclipse take place? Turns out … it’s sooner than you might think.

Blue-colored mass of swirling gas, with jets extending from the center.

What is a quasar?

A quasar is an extremely bright and distant point-like source visible to radio telescopes. The source is a so-called Active Galactic Nucleus, fueled by a supermassive black hole.

Bright stars on very dense star field, with one small, bright, fuzzy patch.

Best observing targets for binoculars

What are the best solar system and deep-sky objects to view to get the most out of your binoculars? From moon-encircled worlds to starry knots in the Milky Way, our list makes the sky’s wonders easy to find.

5 images of the waxing moon tilting over 4 hours.

Do we all see the same moon phase?

No matter where you are on the globe, we all see the same moon. So why do photos from a distant location sometimes look different from what you’re seeing?

What is the Milky Way?

When someone says “Milky Way,” do you think of the starry pathway across our sky, or of the great pinwheel-shaped galaxy in space? Both are correct!

A nearly full reddish Mars seen from orbit, with a giant dark slash covering near a whole hemisphere.

Today is New Year’s Day on Mars

Mars Year 36 begins on February 7, 2021. If you’re looking for a reason to celebrate, here’s to a Happy New Year … on Mars.

Five panels with blue and white Earth nearing the horizon and gone in the last panel.

What does Earth look like from outer space?

If you considered only Earth’s brightness, you could still see our world from as far away as the orbit of the 8th planet, Neptune. In practice, though, from that distance, Earth would be lost in the sun’s glare. How does Earth look from space? Spacecraft photos tell the tale.

Comet with tail upward in a sunset sky.

What’s the difference between asteroids and comets?

Asteroids and comets are generally composed of different stuff. They both orbit our sun, but, for the most part, reside in different parts of our solar system. Yet some rare objects display characteristics of both asteroids and comets.

Hand holding a small, dark, irregular meteorite over hole in doghouse roof.

How to hunt for meteorites

Meteorite hunters find terrain to hike in that is light-colored, with few plants to obscure the ground. They look for rocks that are dissimilar to their surroundings. Later, they analyze the properties of unusual rocks to see if they’ve discovered a meteorite.