321–340 of 513 results
Natural Artistry

Explore the Night with Bob King

Hunting Giant Planetary Nebulae

Mind your elders the next clear night and pay a visit to some of Spring's biggest and most ancient planetary nebulae.

Two For T

Variable Stars

Is T CrB About to Blow its Top?

The recurrent nova T Coronae Borealis last made a splash just after World War II. Does its current restive state hint at an imminent outburst?

Mystery Dark Spot?

Moon

Are You Game for April's Lunar Observing Challenge?

With astronomy being celebrated around the globe this month, join the fun by participating in a unique lunar observing challenge: track down 20 features once thought to show evidence of change from weather, geology, and even life.

252P Drags its Tail

Explore the Night with Bob King

Up, Up, and Away with Comet 252P

With the Moon finally put to bed and Comet 252P still bright, there's no better time than now to see it. Nearby Mars and Saturn only sweeten the deal.

Telescopic view of Comet 252P/LINEAR

Explore the Night with Bob King

Comet 252P Zooms North, BA14 Grows Tail

Splintered comet duo 252P/LINEAR and P/2016 BA14 liven up both dusk and dawn this week. Naked-eye 252P finally debuts in northern skies, while BA14 makes a beeline through the Big Dipper.

And Lo - A Tail!

Celestial News & Events

Comet PanSTARRS 2016's Historic Flyby of Earth

Not one, but two, possibly related comets will make exceptionally close flybys of Earth on March 21–22. Here's what we know and a guide on how to see them.

Smartphone holder for Moon imaging

Astrophotography: Tips & Techniques

Expert Tips for Basic Lunar Imaging

It's easy to take high-quality images of the lunar disk.

Omega Centauri from southwestern New Mexico

Celestial Objects to Observe

How To Get a Glimpse of Omega Centauri

Among globular clusters, the immense Omega Centauri is widely regarded as the most impressive in the sky. Its deep southern location makes this object challenging to spot — but it can be done, as Italian observer Giuseppe Pappa explains.

active region 1520

Sun

How Astronomers Count Sunspots

A multi-year investigation revealed errors in our understanding of the Sun.

Paired Together for Another Week

Explore the Night with Bob King

It's Not Over Till The Fast Planet Sinks

This week and early next will be your last chance to see five planets — six if you count Earth — at dawn.

Capella x 2

Double Stars

Tale of Capella and the Two Red Dwarfs

Bright Capella plays it close to the vest when it comes to companions, but with a good map and steady skies you can track down its dwarf binary.

Blue Q-tip

Comets

Catalina Comet Sails Into Northern Skies

Comet Catalina returns this month with naked-eye potential. Follow its every move with our guide and maps.

Near miss

Occultations

Moon Hides Hyades, Occults Aldebaran Friday

After a late-night ramble through the Hyades cluster, the waning gibbous Moon will cover up the bright star Aldebaran for observers across North America Friday morning.

Monster in our midst

Sun

Observer's Guide to the H-alpha Sun

Want to see a star rock in real time? Observe the Sun in the crimson light of hydrogen alpha and watch it come alive.

Totality on October 27, 2004

Eclipses

Observing and Photographing Lunar Eclipses

Lunar eclipses are leisurely affairs — a pleasure to watch and photograph.

Comet 67P/C-G

Celestial Objects to Observe

Rosetta's Comet Beckons At Dawn

Northern hemisphere observers have this month and next to get their best look at Rosetta's comet, 67P/Churyumov-Gerasimenko.

Asteroids

Let's Get Serious About Ceres

We pay a visit to Ceres, now the apple of the Dawn Mission's eye, as it creeps through Sagittarius this month

Old rock sprinkled atop new

Moon

Rayed Craters on the Moon

Like "catching some rays"? Explore the beauty and dazzle of crater rays, the tracks left by powerful impacts in the not-so-distant past.

Roller-coaster ride south

Explore the Night with Bob King

C/2014 Q1 (PanSTARRS): Next Naked-Eye Comet?

Comet C/2014 Q1 PanSTARRS has been skirting the northern horizon since mid-June. Now it's ready to dip Down Under, where it may be visible with the naked eye in evening twilight.

Non-threatening, favorable pass

Celestial News & Events

See Icarus Wing By Earth This Week

It's no myth. Icarus makes a rare flyby of Earth this week. Here's how to see it in your telescope and live online.