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Achernar is the End of the River

Achernar – aka Alpha Eridani – is the 9th brightest star in the sky and the flattest star known.

Pleiades star cluster, aka Seven Sisters

November’s often called the month of the Pleiades, because it’s when this star cluster – aka the Seven Sisters – shines from dusk until dawn.

See it! Full Hunter’s Moon

This weekend’s Hunter’s Moon, as captured by EarthSky friends around the world. Thank you to all who submitted photos!

What is the moon illusion?

Ever noticed a rising full moon appear huge on the horizon? It’s called the “moon illusion,” and it’s a trick your brain is playing.

2017 Hunter’s Moon on night of November 3

The Northern Hemisphere’s full Hunter’s Moon for 2017 falls the night of November 3. Will it be bigger, brighter, more colorful?

Pisces? Here’s your constellation

How to see the constellation Pisces. Plus sky lore and science.

Al Risha knots Fishes of Pisces

The star Al Risha in the constellation Pisces is not bright. But – at the tip of the graceful V in Pisces – it’s very noticeable.

November 2017 full moon a supermoon?

The 11th of 2017’s 12 full moons falls on November 3-4. It’s the 2nd-closest full moon in 2017, but is it a supermoon?

Taurid fireballs this weekend?

Although a modest shower, perhaps offering 5 meteors per hour, the Taurid shower just might produce some fireballs under the light of the full moon.

Halloween is a cross-quarter day

The 4 cross-quarter days fall between equinoxes and solstices. Halloween is the spookiest one – derived from a sacred festival of ancient Celts and Druids – coming as days grow short and nights long in the Northern Hemisphere.