Mysterious Features on Ganymede
9.12.1997

Where is the rest of the circle? Jupiter's largest moon Ganymede has some truly unusual terrain, including the pictured half circle above cut by nearly parallel curves. Full circles can be easily explained by impact craters, but partial circles imply that some resurfacing has occurred since the original impact.

The McMath-Pierce Solar Observatory
15.03.1996

This odd-looking structure silhouetted in the foreground houses the three largest solar telescopes in the world. Located in Kitt Peak, Arizona, the largest telescope inside the McMath-Pierce Facility is 1.6-meters in diameter and contains only mirrors. The telescope contains no windows or lenses because focusing bright sunlight would overheat them.

Storm Clouds Over Jupiter
27.11.1996

Storm clouds, similar to the familiar cumulonimbus thunderheads of Earth, appear to be present on Jupiter. The mosaic of images above shows the region near the raging edge of Jupiter's Great Red Spot, itself some 2 to 3 Earths wide, as observed by the Galileo spacecraft in June of this year.

M57: The Ring Nebula
16.07.2000

Except for the rings of Saturn, The Ring Nebula (M57) is probably the most famous celestial band. This planetary nebula's simple, graceful appearance is thought to be due to perspective -- our view from planet Earth looking straight into what is actually a barrel-shaped cloud of gas shrugged off by a dying central star.

Watch the Sky Rotate
10.01.2001

If you could watch the sky for an entire night, what would you see? The above time-lapse sequence from the CONtinuous CAMera (CONCAM) project shows the answer for the skies above Kitt Peak National Observatory on 2000 December 23.

M57: The Ring Nebula
22.03.2003

Except for the rings of Saturn, the Ring Nebula (M57) is probably the most famous celestial band. This planetary nebula's simple, graceful appearance is thought to be due to perspective -- our view from planet Earth looking straight into what is actually a barrel-shaped cloud of gas shrugged off by a dying central star.

M57: The Ring Nebula
4.07.2004

Except for the rings of Saturn, the Ring Nebula (M57) is probably the most famous celestial band. This planetary nebula's simple, graceful appearance is thought to be due to perspective -- our view from planet Earth looking straight into what is actually a barrel-shaped cloud of gas shrugged off by a dying central star.

M57: The Ring Nebula
29.07.2001

Except for the rings of Saturn, the Ring Nebula (M57) is probably the most famous celestial band. This planetary nebula's simple, graceful appearance is thought to be due to perspective -- our view from planet Earth looking straight into what is actually a barrel-shaped cloud of gas shrugged off by a dying central star.

Voorwerpjes in Space
4.04.2015

Mysterious Hanny's Voorwerp, Dutch for "Hanny's Object", is really enormous, about the size of the Milky Way Galaxy and glowing strongly in the greenish light produced by ionized oxygen atoms.

The Mountains of Mars
19.07.1995

Volcanic activity on Mars has produced towering mountains. The largest one, Olympus Mons, is pictured here in this Viking Orbiter image. Olympus Mons is a shield volcano nearly 15 miles high and over 300 miles wide at its base.