Larry Sessions
A crescent moon with lines drawn between the 2 horns of the crescent, and a 2nd line drawn perpendicular to the 1st to indicate the sun's whereabouts.

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.

Can you see stars’ different colors?

December is the perfect time for noticing the colors of the stars. Never noticed them? Today’s sky chart can help guide your eye.

Was the Christmas Star real?

Are there any possible astronomical explanations for the Star of Bethlehem or Christmas star?

Sky chart showing an arrow from Orion's Belt to the star Aldebaran.

Aldebaran is the Bull’s fiery eye

Aldebaran – brightest star in Taurus the Bull – is easy to spot at one tip of a V-shaped pattern of stars. If this star replaced our sun, its surface would extend almost to the orbit of Mercury.

Achernar is the End of the River

Achernar is the 9th brightest star and flattest star known. It’s famous as the southernmost bright star in the constellation Eridanus the River. Here’s why much of Earth never sees it … and how you can.

Crab Nebula

The Crab Nebula was an exploding star

The Crab Nebula, about 6,500 light-years from Earth, is the scattered fragments of a supernova, or exploding star, observed by earthly skywatchers in the year 1054.

Use Big Dipper to find North Star

The 2 outermost stars in the bowl of the Big Dipper point to Polaris, the North Star.

A darkened skyline, with smoke from a chimney blowing sideways and a single star, Fomalhaut, above.

Fomalhaut: The loneliest star

It’s also sometimes called the autumn star for us in the Northern Hemisphere. In its large dark patch of sky, only Fomalhaut shines brightly. Here’s how to see it.

Altair: Bright star of the Eagle

Altair is only 16.8 light-years from Earth, making it one of our closest stellar neighbors. At least 2 features of the star make it distinctive. For one thing, Altair needs only 10 hours to spin once on its axis, in contrast to roughly a month for our sun.

A celestial cloud of swirling gases.

See Messier 8, the Lagoon Nebula

The Lagoon – aka M8 – is the largest and brightest nebula, or cloud in space, in the vicinity of the Teapot asterism in the constellation Sagittarius.