Sharpless 171
18.10.2008

Cosmic pillars of cold molecular gas and clouds of dark dust lie within Sharpless 171, a star-forming region some 3,000 light-years away in the royal constellation Cepheus. This tantalizing false-color skyscape spans about 20 light-years across the nebula's bright central region.

Red Sun Streaming
7.01.1997

The Sun is leaking. In fact, it is gushing: particles stream away from the Sun at hundreds of kilometers per second. Some of these particles strike the Earth and cause aurora. Most particles, however, either surround the Sun as a huge solar corona or glide into interstellar space as the solar wind.

Moon Robot: Lunokhod 1
20.04.1997

On November 17, 1970 the Soviet Luna 17 spacecraft landed the first roving remote-controlled robot on the Moon. Known as Lunokhod 1, it weighed just under 2,000 pounds and was designed to operate for 90 days guided by a 5-person team at the Deep Space Center near Moscow, USSR, Planet Earth.

Dusting Spiral Galaxies
16.01.1998

How much dust is in spiral galaxies? Does it block out much of the starlight? Because astronomers rely on an accurate knowledge of galaxy properties to investigate a wide range of problems, like galaxy and quasar evolution and the nature of dark matter, answers to simple questions like this are key.

Mars Volcano Apollinaris Patera
13.05.1999

Dwarfed by Olympus Mons and the other immense shield volcanos on Mars, Apollinaris Patera rises only 3 miles or so into the thin martian atmosphere, but bright water-ice clouds can be still be seen hovering around its summit.

APOD: 2025 August 30 Б A Two Percent Moon
30.08.2025

A young crescent moon can be hard to see. That's because when the Moon shows it's crescent phase (young or old) it can never be far from the Sun in planet Earth's sky.

Contemplating the Sky
13.08.2002

Have you contemplated your sky recently? Last night was a good one for midnight meditators at many northerly locations as meteors from the Perseid meteor shower frequently streaked through. The Perseid meteor shower has slowly been building to a crescendo but should continue to be rewarding tonight and into the week.

The Weather on Mars
24.03.1997

Would Mars be a nice place to visit? Sometimes. Much of Mars undergoes severe changes in climate during its orbit around the Sun, ranging from extreme cold to temperatures enjoyable by humans. But Mars...

The Mysterious Rings of Supernova 1987a
5.07.1996

What's causing those odd rings in supernova 1987a? In 1987, the brightest supernova 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.

Saturns Rings Seen Sideways
18.10.1998

Saturn's rings are actually very thin. This picture from the Hubble Space Telescope was taken on August 6, 1995 when the rings lined up sideways as seen from Earth. Saturn's largest moon Titan is seen on the left, and Titan's shadow can be seen on Saturn's cloud tops!