Sign Up for Our Amazing Newsletter!
A daily update by email. Science news, great photos, sky alerts.
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.
Posts by
Larry Sessions
Kochab and Pherkad: The Guardians of the Pole
Kochab and Pherkad are two stars in the Little Dipper that carry the nickname of the Guardians of the Pole. Here's how to find them and more.
August 31, 2022
Tonight
Moon and Gemini stars on April 8 and 9
On April 8 and, 9, 2022, you'll find the a 1st-quarter moon near Castor and Pollux, the two brightest stars in the constellation Gemini the Twins. Also nearby is Procyon, the brightest star in the constellation Canis Minor the Lesser Dog.
April 8, 2022
No leap second for December 31, 2021
World timekeepers have decreed there will be no leap second on December 31, 2021. Overall the spin of Earth is slowing down, but in 2020 it sped up.
December 31, 2021
The enduring mystique of Barnard’s Star
Sometimes called Barnard's Runaway Star, it's one of the best known stars in the history of astronomy and in popular culture.
November 14, 2021
Leo loses his tail. We gain a constellation
The constellation Leo once had a tail, a clump of faint stars. Now these same stars are known as Coma Berenices, the hair of a queen.
April 9, 2021
The Large Magellanic Cloud, a galactic neighbor
The Large Magellanic Cloud dwarf galaxy, visible all year round in the Southern Hemisphere, is somewhere between spiral and irregular in shape.
December 17, 2020
Find the Geminids’ radiant point
Why is the Geminid meteor shower best around 2 a.m.? It's because that's when the shower's radiant point - near the bright star Castor in the constellation Gemini - is highest in the sky.
December 11, 2020
Quarter moon or a half moon?
Half the moon always faces us. And half the moon is always lit by the sun. But, in the language of astronomers, there are no 'half moons.'
August 25, 2020
Moon phase a clue to the sun’s position
If you look in a clear western sky at dusk and early evening, you should spot the waxing crescent moon. Notice that its lighted crescent points toward the sunset.
December 31, 2019
First quarter moon on February 12
The side of the moon we see from Earth appears 50% illuminated tonight. For all of Earth, the moon rises around midday and sets around midnight. Plus the moon's lighted side points right at Mars tonight!
February 12, 2019
