Why is QSO 1229+204 so Bright?
24.08.1996

What causes the center of this barred spiral galaxy to light up brighter than almost anything in the universe? The quasar there is a good fraction of the way across our observable universe...

Europa's Ice Rafts
10.04.1997

The surface of Jupiter's moon Europa has shifted. Photographs released yesterday of Europa's surface taken by the spacecraft Galileo show that the smooth moon's icy surface is sometimes like a giant scrambled jigsaw puzzle. Pieces of Europa's surface, identifiable above, have rafted to new locations.

Dark Sky, Bright Sun
2.09.1997

In low Earth orbit there is not enough atmosphere to diffuse and scatter sunlight, so shadows are black and the sky is dark - even when the Sun shines. The harsh lighting produced this dramatic...

NGC 604: Giant Stellar Nursery
11.04.1998

Scattered within this cavernous nebula, cataloged as NGC 604, are over 200 newly formed hot, massive, stars. At 1,500 light-years across, this expansive cloud of interstellar gas and dust is effectively a giant stellar nursery located some three million light-years distant in the spiral galaxy, M33.

Far Side of the Moon
8.10.1998

Locked in synchronous rotation, the Moon always presents its well-known near side to Earth. But from lunar orbit, Apollo astronauts also grew to know the Moon's far side. This sharp picture from Apollo...

A New Jupiter Oval Rotates
5.01.1999

Even Jupiter can do the twist. Large cloud systems on Jupiter rotate, and the newly formed oval pictured above is no different. This new oval formed earlier this year from the collision of two smaller ovals: an occurrence not unlike two large storms merging into one huge hurricane.

The Millennium that Defined Earth
31.12.1999

When the second millennium began, people generally knew that the Earth was round, but few saw much of it beyond their local village. As the millennium progressed, humans mapped the continents, circumnavigated the globe, and determined the composition of the Earth.

A Sundial that Shows Solstice
26.06.2012

What time is it? If the time and day are right, this sundial will tell you: SOLSTICE. Only then will the Sun be located just right for sunlight to stream through openings and spell out the term for the longest and shortest days of the year. And that happened last week and twice each year.

Saturn's Cleanest Moon: Enceladus
25.11.1995

Enceladus orbits Saturn between the smaller Mimas and the larger Tethys. Enceladus is composed mostly of water ice and has the cleanest and purest ice surface in the Solar System. It's surface therefore appears nearly white. The surface also has many unusual groves and relatively few craters, like Jupiter's moon Ganymede.

A String Of Pearls
1.08.1998

Comet Shoemaker-Levy 9, named after its co-discoverers, was often referred to as the "string of pearls" comet. It is famous for its suggestive appearance as well as its collision with the planet Jupiter!