SUNSET: 
Sky at a Glance | April 27th, 2007
Watch Venus pass a not-quite-first-magnitude star in the western evening sky this week. Meanwhile, Saturn shines in fine view much higher during evening, and Jupiter is well placed before dawn.
Transit of Luna
Click on image for a 2MB animation.NASAOn February 25th the Moon crossed the Sun in an unearthly annular eclipse — one that can never be seen from Earth. These ultraviolet images were taken by one of NASA’s two STEREO solar observatories, which were launched last October and are now watching…
Comet Chaos in the Helix's Heart
Colliding solid bodies, probably comet nuclei, have created a dusty debris disk near the center of the Helix planetary nebula in Aquarius, as revealed in infrared images from NASA's Spitzer Space Telescope.
Life with a Red Dwarf
The commonest stars in the universe aren't very Sun-like — but they could still have life-bearing planets. However, those worlds aren't like anything you've ever seen. Imagine a home world where half of the planet basks in eternal day, the other cloaked in eternal night.
Comet SWAN Still Glows After Dusk
Comet SWAN remains a nice but fading target for telescopes in early evening. Follow it using our chart.
DIY: Astronomy Projects & Guidance
Dealing With Dew: Dew Heaters, Dew Shields and More
How to keep your optics dry and clear even on the dampest, dewiest nights.
Chi Cygni's Record-Breaking Maximum
The red, Mira-type variable star Chi Cygni has had a very unusual maximum. It's one of the brightest such variables to begin with (typically peaking at about magnitude 5.2), but in late July and early August 2006, it peaked at about magnitude 3.8.
Catch a Naked-eye Sunspot
There's a nice big naked-eye spot on the Sun today, even though we're near the minimum of the 11-year sunspot activity cycle. Of course, when we're talking about the Sun, "naked-eye" means looking through a safe solar filter.
How to Safely See a Partial Solar Eclipse
Looking at the Sun is harmful to your eyes at any time, partial solar eclipse or no. Fortunately, there are many easy ways to watch the show safely.
Mars Hoax Returns
Don't be misled. Once again, an e-mail chain letter making the rounds of the Internet suggests that Mars will look as big as the full Moon to the naked eye in late August. Nonsense! Even at its closest and brightest, Mars never looks like anything more than a bright, orangish star unless you view it through a telescope.
Observing the Perseids - A Perennial Guide
The Perseids meteor shower is one of the year's top astronomical highlights. Learn how best to see the meteors.
Equipment: Guides & Recommendations
The Art of Using a Telescope
Congratulations — you've followed our advice and bought the telescope that's best for you. Now learn how to get the most out of it.
The Spectral Types of Stars
Without its spectral type, a star is a meaningless dot of light.
The Stellar Magnitude System
Why do larger numbers mean less light? Here's the story of astronomy's odd but beloved scheme for describing star brightnesses.
The Lure of Variable Stars
Studying and recording the ups and downs of variable stars is a pleasant pastime that can also be scientifically rewarding. Here's a simple project to get you going.
The Setting Circles on Your Telescope
Beginners should ignore them and learn to navigate the sky by eyeball instead. However, setting circles do have their uses -- if you make all the right adjustments first.
A Galaxy-Hop in Leo
Even with a modest telescope and a poor sky, you can ferret out many faint, far galactic wonders by using a good map.
How to Care for Your Telescope Optics the Right Way
The mirror in your telescope will probably work fine with a bit of dust on it, but if it's really dirty, you may want to clean it — carefully!
Occultations: The Fastest Things in the Sky
Watch in your telescope as the edge of the Moon snaps a star out of sight.
How far away are the stars I see through my telescope?
The faintest stars I can see in my 4-inch refractor are 12th magnitude. If one of these stars is just like the Sun, how far away is it? The Sun would be magnitude 12.0 if it were 880 light-years away. That’s not very far in the grand scheme of the…
