1061–1080 of 1,191 results
dew-it-yourself heater

DIY: Astronomy Projects & Guidance

DIY Dew Heater

With just a little electrical know-how you can make an antidew heater that suits your scope.

Variable Stars

R and T Coronae Borealis: Two Stellar Opposites

One is usually bright but fades unexpectedly; one is almost always faint but brightens unexpectedly. Check them out with binoculars.

Aligning an equatorial mount on Polaris

DIY: Astronomy Projects & Guidance

Accurate Polar Alignment with Your Telescope

Long-exposure astrophotography requires an accurately aligned equatorial mount.

Looking at the exit pupils

Choosing Your Astronomy Equipment

A Pupil Primer: How Big Should a Telescope's Exit Pupil Be?

Image brightness, magnification, and why the old ideal of a 7-millimeter exit pupil is not so ideal at all.

Sun through hydrogen-alpha filter

Celestial Objects to Observe

Observing the Sun Safely: Sunspots, Faculae, and Flares

The surface of the Sun is a dynamic, living place that can change unpredictably from day to day.

urban observer

Deep Sky

Observing Secrets of Deep-Sky Objects Revealed

Here's how to hone your galaxy-hunting skills — and what to expect at the eyepiece.

Light pollution illustration.

Save Dark Skies

Light Pollution In The Night Sky

Light pollution has become so pervasive that it compromises the view of the universe for an estimated 90 percent of Americans.

Celestial News & Events

Watch the Re-Entry of Stardust

Late Saturday night, January 14-15, skywatchers in much of the American West can watch for a dazzling artificial "meteor."

Astronomy & Observing News

Mars News, True and False

It's unkillable! A two-year old e-mail chain letter is misleading people into expecting Mars to go nuts in August.

Astronomy & Observing News

New Amateur Asteroid Awards

Congress has established $2,000 annual prizes for U.S. amateurs who discover near-Earth asteroids or aid asteroid research.

Black Holes

Binary Quasar Is No Illusion

A close pair of quasars in Pisces turns out just that, not the record-breaking gravitational lens that astronomers had hoped.

Celestial News & Events

Asteroid Flyby Caught!

On July 3, 2006, an 800-meter (half-mile) asteroid called 2004 XP14 flew past Earth at a distance a little greater than that of the Moon.

Press Releases

Comet Schwassmann- Wachmann 3 at Its Best

This periodic comet, due to fly close by Earth in May, is breaking into even more pieces. The brightest one may reach 4th magnitude.

Celestial News & Events

Comet To Cross Ring Nebula!

On Sunday night for North America, the brightest piece of Comet Schwassmann-Wachmann 3 goes right over the Ring Nebula in Lyra.

Astronomy & Observing News

A Big New Step in the Search for ET

The world's largest optical SETI telescope begins sweeping millions of stars for laser signals from alien civilizations.

Astronomy & Observing News

Why Galaxies Tilt Just So

Spiral galaxies like the Milky Way got oriented by forces shaping the entire cosmos.

Celestial News & Events

The April 1st Pleiades Occultation

The waxing crescent Moon made quite a spectacle crossing the Pleiades on April Fool's Day 2006.

Press Releases

The March 29th Solar Eclipse

Europe, Africa, and parts of Asia are in line to get Moon-shadowed next Wednesday.

Astronomy & Observing News

First Picture from Mars Reconnaisance Orbiter

Having entered Martian orbit, NASA's latest explorer has tried out its record-breaking camera.

Celestial Objects to Observe

RS Ophiuchi Finally Blows its Stack

This famous recurrent nova has just erupted for the first time in 21 years, reaching magnitude 4.8 on February 13th.