Mercury And The Moon
11.11.1999

Mercury is the closest planet to the Sun and never moves far from our parent star in Earth's sky. Racing around its tight orbit, this well-done world is a little over 1/3 the diameter of Earth and is often lost to our view in the solar glare.

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.

On the Origin of Gold
15.10.2017

Where did the gold in your jewelry originate? No one is completely sure. The relative average abundance in our Solar System appears higher than can be made in the early universe, in stars, and even in typical supernova explosions.

Many Moons
5.07.2002

Whimsical and creative, this multiple exposure suggests that planet Earth's sky could be very dramatic indeed if it were graced by many moons. And in James Thurber's well-known children's story, Princess...

Crossing The Ring Plane
1.08.1995

"I do not know what to say in a case so surprising, so unlooked for and so novel." announced Galileo when Saturn's rings appeared to vanish in 1612. In fact, every 15 years Saturn's rings seem to almost disappear as viewed from the Earth.

Moving Echoes Around SN 1987A
24.10.1997

Yesterday's image highlighted reflective rings of light emitted by a supernova explosion. Today's pictures, taken over a year apart, highlight how these echoes are seen to move over time. Visible...

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.

A Spherule from the Earths Moon
15.02.2004

How did this spherule come to be on the Moon? When a meteorite strikes the Moon, the energy of the impact melts some of the splattering rock, a fraction of which might cool into tiny glass beads. Many of these glass beads were present in lunar soil samples returned to Earth by the Apollo missions.

Moon Occults Saturn
8.05.1999

On September 18, 1997, many stargazers in the U. S. were able to watch a lovely early morning lunar occultation as a bright Moon passed in front of Saturn. Using a 1.2 meter reflector, astronomer Kris Stanek had an excellent view of this dream-like event from the Whipple Observatory atop Arizona's Mount Hopkins.

Four Years of Saturn
6.04.2007

Saturn and its magnificent ring system can offer even casual astronomers the most memorable of telescopic sights. Wandering between Leo and Cancer this month, a bright Saturn is well placed for viewing in evening skies. But from our earthbound perspective, the tilt of Saturn's rings does change with time.