A Sirius culmination

Photo by Project Nightflight during a culmination of the sky's brightest star, Sirius, above the volcanos of La Palma in the Canary Islands.

A binocular comet

Comet 45P/Honda-Mrkos-Pajdusakova on December 22, 2016.

Venus and a cloud shadow

Another sunset spectacle from Peter Lowenstein's hilltop perch above Mutare, Zimbabwe.

Arc and 2 sundogs over Illinois

Halos like this one around the sun or moon are caused by ice crystal high in Earth's sky. Notice the upside-down rainbow-like arc above. It's called a circumzenithal arc.

Snow in the Sahara Desert

Snow in a place where summertime temperatures are high - though wintertime temps can drop to freezing - and where precipitation from the skies is rare.

Solstice sun rolling down the hill

An 8-frame animation of the sun setting behind Tijuca Peak in Rio de Janeiro, Brazil, 10 hours after the Southern Hemisphere's summer solstice.

Setting sun apparition

"A couple of bright blobs of orange light appeared for one minute ... in almost the exact position where the sun usually sets for the few days around our summer solstice."

Snow, lit by full moon, from space

An Arctic air mass brought snow to the northern U.S. last week. A lake-effect snow followed an earlier snow accumulation. A NASA satellite caught the view from space, under full moonlight.

Ursid meteors are flying

The moon is up during the best hours for watching (after midnight). Still, people are catching Ursid meteors. This one was a bright one! The Ursid shower peaks this week.

Ice monster lighthouse

"The lighthouse is starting to look like an ice monster," said Joshua Nowicki. He took this shot on December 15 on the north pier in Saint Joseph, Michigan.