Ice Volcanoes on Mars
29.06.2001

What causes these unusual cone-shaped features on Mars? Spanning an average of only 100 meters at the base, these small cones appear near massive Martian volcanoes such as Olympus Mons. Near the cones are also dry channels and eroded banks.

Tail Wags of Comet Ikeya Zhang
15.05.2002

As Comet Ikeya-Zhang approached the Sun two months ago, it developed a complex blue ion tail. The tail was composed of ions that boiled off the nucleus and were pushed away from the Sun by the out-flowing fast-moving particles of the solar wind.

Venus and the Chromosphere
11.06.2004

Enjoying the 2004 Transit of Venus from Stuttgart, Germany, astronomer Stefan Seip recorded this fascinating, detailed image of the Sun. Revealing a network of cells and dark filaments against a bright solar disk with spicules and prominences along the Sun's limb, his telescopic picture was taken through an H-alpha filter.

Transit of Venus Stereogram
17.07.2004

Venus glides in front of an enormous solar disk in these two frames from the TRACE satellite imaging of the inner planet's 2004 transit. Arranged in a "right/left" stereogram, the frames are intended...

ISS and Discovery Transit the Sun
29.07.2005

That large sunspot near the right edge of the Sun is actually not a sunspot at all. It's the International Space Station (ISS) docked with the Space Shuttle Discovery on mission STS-114.

Sunrise by Season
21.12.2005

Does the Sun always rise in the same direction? No. As the seasons change, the direction toward the rising Sun will change, too. The Sun will always rise and set furthest to the south during the day of Winter Solstice, and furthest to the north during Summer Solstice.

Neptune through Adaptive Optics
18.02.2000

From the Earth's surface, Neptune usually appears as a fuzzy blotch. The blurring effects of the Earth's atmosphere deny clearer images. By distorting mirrors in the telescope itself in time with the changing atmosphere, however, these effects can be greatly reduced.

Verona Rupes: Tallest Known Cliff in the Solar System
23.07.2007

Could you survive a jump off the tallest cliff in the Solar System? Quite possibly. Verona Rupes on Uranus' moon Miranda is estimated to be 20 kilometers deep -- ten times the depth of the Earth's Grand Canyon.

Lightning Over Athens
20.07.2010

Have you ever watched a lightning storm in awe? Join the crowd. Oddly, nobody knows exactly how lightning is produced. What is known is that charges slowly separate in some clouds causing rapid electrical discharges (lightning), but how electrical charges get separated in clouds remains a topic of much research.

Verona Rupes: Tallest Known Cliff in the Solar System
4.04.2011

Could you survive a jump off the tallest cliff in the Solar System? Quite possibly. Verona Rupes on Uranus' moon Miranda is estimated to be 20 kilometers deep -- ten times the depth of the Earth's Grand Canyon.