Astronomy Essentials

How to see binocular comet C/2017 O1

By Eddie Irizarry in Astronomy Essentials | 1 day ago

Long-period comet C/2017 O1 – a visitor from the Oort Comet Cloud – is becoming visible in small telescopes and binoculars. This post includes charts that can help you find it.

Day and night exactly equal at equinoxes?

By Bruce McClure in Astronomy Essentials | Earth | 1 day ago

On the day of an equinox, the center of the sun would set about 12 hours after rising – given a level horizon, as at sea, and no atmospheric refraction.

EarthSky’s meteor shower guide for 2017

By Bruce McClure and Deborah Byrd in Astronomy Essentials | Space | 4 days ago

A whole series of awesome meteor showers is about to start. Click in for information on how to watch the Draconids, Orionids, Taurids, Leonids and Geminids!

Andromeda galaxy next door to Milky Way

By Bruce McClure in Astronomy Essentials | Clusters Nebulae Galaxies | 6 days ago

The Andromeda galaxy is the closest spiral galaxy to our Milky Way and the most distant thing you can see with your eye alone. Find it in your night sky!

Another X-flare from the sun

By Deborah Byrd in Astronomy Essentials | 1 week ago

We’re near solar minimum, but the sun has been active! Click here for a video of solar flares so far in September, 2017 and for news for the sun’s most recent X-flare.

How to see the Great Square of Pegasus

By EarthSky in Astronomy Essentials | Favorite Star Patterns | 1 week ago

It’s easy! The Great Square of Pegasus consists of 4 stars of nearly equal brightness in a large square pattern. Once you find it, you can star-hop to other well-known sights in the sky.

Star of the week: Delta Cephei

By Bruce McClure and Deborah Byrd in Astronomy Essentials | Brightest Stars | 2 weeks ago

Delta Cephei doubles in brightness every 5.36 days and thereby helped establish the known distance scale of our galaxy and universe.

Giant sunspots, solar flares, aurora alert!

By Deborah Byrd in Astronomy Essentials | Today's Image | 2 weeks ago

Sunwatchers are still tracking those 2 large sunspot groups making their way across the Earth-facing side of the sun. Then yesterday there was an X-flare! Watch for possible auroras.

See an extra-red moon or sun this week?

By Deborah Byrd in Astronomy Essentials | Earth | 2 weeks ago

If you live in the U.S. or Canada, a peculiarly red moon – or very spectacular sunrise or sunset – might be due to smoke from wildfires. Click in for images from Earth and space.

Watch for zodiacal light or false dawn

By Deborah Byrd and Bruce McClure in Astronomy Essentials | 2 weeks ago

The zodiacal light is an eerie light extending up from the horizon. No matter where you are on Earth, springtime or autumn is the best time to see it.

How Earth looks from outer space

By Deborah Byrd in Astronomy Essentials | 2 weeks ago

If you were looking with the eye alone, how far away in space would our planet Earth still be visible?

Asteroid Florence found to have 2 moons

By Eddie Irizarry in Astronomy Essentials | Space | 2 weeks ago

3122 Florence passed yesterday, biggest near-Earth object to pass so close in a century. Radar revealed 2 orbiting moons! Plus a chart that’ll help you spot the asteroid.

September guide to the bright planets

By Bruce McClure and Deborah Byrd in Astronomy Essentials | 3 weeks ago

Jupiter and Saturn are evening planets. Venus, Mercury and Mars are morning planets. Watch for the close conjunction of Mercury and Mars around mid-September.

Capricornus? Here’s your constellation

By Bruce McClure in Astronomy Essentials | Constellations | 3 weeks ago

No matter where you live worldwide, Capricornus the Sea-goat climbs highest in the sky in early September. How to see it, and how a sea-goat came to reside among the stars.

Alpha Cephei is a rapidly rotating star

By Bruce McClure and Deborah Byrd in Astronomy Essentials | Brightest Stars | 3 weeks ago

While not one of the most conspicuous stars in the night sky, Alderamin – aka Alpha Cephei – is easy to spot, and is interesting for its rapid rotation on its axis.

When is the Harvest Moon in 2017?

By Deborah Byrd in Astronomy Essentials | 3 weeks ago

In 2017, the autumnal equinox for the Northern Hemisphere comes on September 22. Official Harvest Moon is October 5, but the September 5-6 full moon shares the characteristics of a Harvest Moon.