The Hydrogen Clouds of M33
3.10.2019

Gorgeous spiral galaxy M33 seems to have more than its fair share of glowing hydrogen gas. A prominent member of the local group of galaxies, M33 is also known as the Triangulum Galaxy and lies a mere 3 million light-years away.

Twisting Meteor Train
27.11.1998

Blazing through the sky at 70 kilometers per second, 100 kilometers or so above planet Earth, many bright Leonid meteors left behind a persistent, smoke-like trail of glowing, hot, ionized gas. Twisting in high altitude winds, these trails or trains typically were visible for many minutes.

A Winter Solstice
21.12.1997

Today is the Winter Solstice, the shortest day of the year in the Northern Hemisphere. The yearly cycle of Seasons on planet Earth once again finds the Sun at its lowest point in the Northern Sky.

The Mysterious Rings of Supernova 1987A
31.03.2002

What's causing those odd rings in supernova 1987A? In 1987, the brightestsupernova in recent history occurred in the Large Magellanic Clouds. At the center of the picture is an object central to the remains of the violent stellar explosion.

The Orion Nebula from Subaru
2.02.1999

The Orion Nebula (M42) shows a host of treasures when viewed in infrared light. Some stars in the Trapezium, an open cluster of stars at the center, are only visible in infrared light. The orange feature above center is called the Kleinman-Low Nebula, and appears greatly affected by newly forming central star IRc2.

Jupiter's Auroras
18.10.1996

Auroras are especially large on Jupiter. In pictures released yesterday, the Hubble Space Telescope imaged these unusual light displays in more detail than ever before. Jupiter's auroras are linked to its volcanic moon Io.

NGC 6302: The Butterfly Nebula
2.06.1998

The Butterfly Nebula is only thousands of years old. As a central star of a binary system aged, it threw off its outer envelopes of gas in a strong stellar wind. The remaining stellar core is so hot it ionizes the previously ejected gas, causing it to glow.

Nebulosity in Sagittarius
10.08.1997

What causes the colors in this beautiful nebulosity in Sagittarius? Dubbed NGC 6589 and NGC 6590, the colors of this nebulosity, are caused by gas and dust. The blue color of the nebula nearest the bright stars is caused by reflection off interstellar dust.

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.