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Sun on the sky’s equator

Another great explanation of Friday’s equinox – plus beautiful graphics – from astronomer Guy Ottewell.

All you need to know: September equinox

2017’s September equinox arrives on the 22nd. Happy autumn (or spring)!

How to see binocular comet C/2017 O1

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?

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

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

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

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

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.

Delta Cephei is a famous variable star

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!

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?

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

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

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

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

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

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

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?

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.

Astro festivals, star parties, workshops

What could be more fun on a cool, crisp autumn evening than a star party? Find a 2017 star party near you.

Biblical signs in the sky?

Will the sky on September 23, 2017 mirror “signs” from the Book of Revelation in the Bible? An astronomer responds.