Highlights of the North Spring Sky
13.03.2019

What can you see in the night sky this season? The featured graphic gives a few highlights for Earth's northern hemisphere. Viewed as a clock face centered at the bottom, early (northern) spring sky events fan out toward the left, while late spring events are projected toward the right.

In the Heart of the Tarantula Nebula
20.05.2018

In the heart of monstrous Tarantula Nebula lies huge bubbles of energetic gas, long filaments of dark dust, and unusually massive stars. In the center of this heart, is a knot of stars so dense that it was once thought to be a single star.

Lunar Eclipse over Cologne Cathedral
22.01.2019

Why would a bright full Moon suddenly become dark? Because it entered the shadow of the Earth. That's what happened Sunday night as the Moon underwent a total lunar eclipse. Dubbed by some...

Blue Straggler Stars in Globular Cluster M53
7.02.2021

If our Sun were part of this star cluster, the night sky would glow like a jewel box of bright stars. This cluster, known as M53 and cataloged as NGC 5024, is one of about 250 globular clusters that survive in our Galaxy.

Bright Lights, Dark City
18.08.2003

Last Thursday, millions of people had an unexpectedly good view of a dark night sky. Usually, the reflection of city lights off of local air impurities makes it hard for casual observers to see more than a handful of stars from a bright urban area.

APOD: 2026 July 21 Б Turtle Rock on Mars
21.07.2026

Is this a fossilized turtle on Mars? No. Although resembling a large Earth tortoise, this is a layered rock outcrop on Mars that is estimated to span about 15 meters, making it much larger than turtles on Earth.

NGC 1316: After Galaxies Collide
4.04.2005

How did this strange-looking galaxy form? Astronomers turn detectives when trying to figure out the cause of unusual jumbles of stars, gas, and dust like NGC 1316. A preliminary inspection indicates that NGC 1316 is an enormous elliptical galaxy that includes dark dust lanes usually found in a spiral.

Asperatus Clouds Over New Zealand
27.02.2013

What kind of clouds are these? Although their cause is presently unknown, such unusual atmospheric structures, as menacing as they might seem, do not appear to be harbingers of meteorological doom. Known informally...

Doomed Star Eta Carinae
20.02.2019

Eta Carinae may be about to explode. But no one knows when - it may be next year, it may be one million years from now. Eta Carinae's mass - about 100 times greater than our Sun - makes it an excellent candidate for a full blown supernova.

Saturns Hexagon Comes to Light
14.12.2009

Believe it or not, this is the North Pole of Saturn. It is unclear how an unusual hexagonal cloud system that surrounds Saturn's north pole was created, keeps its shape, or how long it will last.