A Colorful Aurora
1.09.1998

A solar storm overtook the Earth on August 26th. The Earth survived unscathed, as usual, although many northerners reported an impressive display of aurora. Many of these auroras changed rapidly, with patterns appearing and disappearing sometimes in less than a second. Out away from city lights, observers also reported an unusually spectacular array of colors.

The Cat's Paw Nebula
7.12.1999

As soon as we find out whose cat did this . . . Nebulae are as famous for being identified with familiar shapes as perhaps cats are for getting into trouble. No cat, though, could have created the vast Cat's Paw Nebula visible in Scorpius.

Planets and Fire by Moonlight
9.07.2008

On July 5th, wandering planets, bright stars, and a young crescent Moon graced western skies after sunset. Arrayed along the solar system's ecliptic plane, the three celestial beacons forming this skyscape's eye-catching line-up with the Moon are Saturn (upper left), then Mars, and finally Regulus, alpha star of the constellation Leo.

Aurora Australis
4.07.2015

Not fireworks, these intense shimmering lights still danced across Earth's night skies late last month, seen here above the planet's geographic south pole. The stunning auroral displays were triggered as a coronal mass ejection blasted from the Sun days earlier impacted the magnetosphere, beginning a widespread geomagnetic storm.

A Green Flash of Spring
9.04.2016

Taken on March 20 from the top of Haleakala on the isle of Maui, planet Earth, the first sunrise of northern spring is pictured in this vacation snapshot. The telephoto view from the volcanic caldera above a sea of clouds also captures an elusive green flash near the Sun's upper limb.

Planets on the Wing
6.01.2018

Lately, bright Jupiter and fainter Mars have been easy to spot for early morning skygazers. Before dawn on January 7 the two naked-eye planets will reach a close conjunction near the horizon, only 1/4 degree apart in predawn eastern skies. That apparent separation corresponds to about half the angular diameter of a Full Moon.

The Year of Distant Supernovae
31.12.1998

Distant supernovae were among topics at the forefront of astronomy during 1998. Two independent groups raced to deploy large telescopes to scan the sky, discovering and analyzing far-off supernovae with the promise of calibrating the geometry of our universe.

The Cygnus Loop
23.06.2001

The shockwave from a 20,000 year-old supernova in the constellation of Cygnus supernova explosion is still expanding into interstellar space. The collision of this fast moving wall of gas with a stationary cloud...

The Small Cloud of Magellan
19.07.1997

The southern sky contains wonders almost unknown in the north. These wonders include the Large and Small Magellanic Clouds: small irregular galaxies orbiting our own larger Milky Way spiral galaxy. The Small Magellanic Cloud (SMC), pictured here, is about 250,000 light years away.

The Butterfly Planetary Nebula
21.10.1997

As stars age, they throw off their outer layers. Sometimes a highly symmetric gaseous planetary nebula is created, as is the case in M2-9, also called the Butterfly. Most planetary nebulae show this bipolar appearance, although some appear nearly spherical.