Cassiopeia A: A Festive Supernova Remnant

New near-infrared observations from the Webb telescope reveal intricate strands of debris from the exploded star.

Buried Polygons on Mars Point to “Stark Environmental Transition”

Polygons buried beneath the surface of Mars indicate an abrupt transition in the planet’s early history.

This Week's Sky at a Glance, December 15 – 23

The Moon's first meetup with an easy naked-eye planet this lunation comes on Sunday evening the 17th, when the Moon is 3° below or lower left of Saturn in early evening (for North America).

Vesta Sets Sail Across Orion

Look who’s visiting this winter in Orion: Vesta, a bright asteroid with a dark side.

Watch Jupiter's Moons in Unusual Lineups

You’ll have four opportunities in the coming months to see Jupiter’s moons in interesting configurations.

December Podcast: A Tower of Brilliant Stars

This month’s Sky Tour podcast introduces you to a “tower of brilliance” in the eastern evening sky, along with tips for finding four planets and watching mid-December’s impressive Geminid meteor shower.

Rahal Cosmos '23

A south-asian virtual solo astronomy quiz competition organized by the Astronomical Society of Rahula College, Matara, Sri Lanka.