A quasar is an extremely bright, distant object visible to radio telescopes. The source is an active galactic nucleus fueled by a supermassive black hole.

Can you still see Venus in the east before sunrise? It's easier from Earth's Southern Hemisphere than from the northern half of the globe. If you can see it, you just might catch the furtive rendezvous of Venus and Saturn at dawn on February 6, 2021.

Redshifts reveal how an object is moving in space, showing otherwise-invisible planets and the movements of galaxies, and the beginnings of our universe.

How to spot the radiant point for the Delta Aquariid meteor shower, going on now. Plus ... why meteors in annual showers have radiant points.

In the year 2021, the moon will swing to its farthest point from Earth on May 11, 2021, and then will come closest to Earth on December 4, 2021.

Lunar months are the time between successive new moons. A lunar month is also called a lunation or a synodic month.

The sun entered the constellation Sagittarius on December 18, 2020. It'll cross into the constellation Capricornus on January 19, 2021. Look here for dates of the sun's entry into the zodiacal constellations for 2021.

Jupiter and Saturn's great conjunction - where they appeared exceedingly close on the sky's dome - was December 21. Thank you to EarthSky community members from around the world who captured photos!

Jupiter and Saturn at conjunction are only 0.1 degree apart. Don't miss them! Info, charts, photos here.

December solstice sunrise comes at the same time for St. Augustine, Florida, and New York City. But St. Augustine has an hour more of daylight than New York. Here's why.