Mimas: Small Moon with a Big Crater
25.04.1999

Mimas is one of the smaller moons of Saturn but shows one of the largest impact craters. In fact, if the impact had been much greater, it would have disrupted the entire satellite. The large crater has been named Herschel after the 1789 discoverer of Mimas, Sir William Herschel.

A Sundial for Mars
28.04.1999

When Mars Surveyor arrives at Mars in 2002, it will carry a sundial. Even though batteries and a solar array will power the Mars Surveyor Lander, the sundial has been included to allow a prominent public display of time.

On the Origin of Gold
18.05.2008

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.

Cities at Night
5.03.2016

Looking toward the south from an altitude of 400 kilometers, this stunning snapshot from orbit finds bright lights of Tokyo and cities across central and southern Japan, planet Earth shining upward through broken clouds. The spacefaring perspective was captured last July by astronaut Scott Kelly during his stay on board the International Space Station.

Columbia Waits, Discovery Launches
8.08.1995

Space Shuttle Discovery launches while the Space Shuttle Columbia is readied for a future mission. Space shuttles are launched from the Kennedy Space Center in Florida. At this date there are four operating space shuttles: Atlantis, Columbia, Discovery, and Endeavour. This mission is most famous for carrying the Hubble Space Telescope into orbit.

Io's Sodium Cloud
28.04.1997

Io has its own cloud. Jupiter's most active moon is visible on the left of the above false-color photograph, with its left side illuminated by sunlight. But what is happening on Io's right side? Here a plume of gas from the active volcano Prometheus also reflects sunlight.

Closeup of Antennae Galaxy Collision
27.10.1997

It's a clash of the titans. Two galaxies are squaring off in Corvus and here are the latest pictures. When two galaxies collide, however, the stars that compose them usually do not. This is because galaxies are mostly empty space and, however bright, stars only take up only a small amount of that space.

NGC 2440: Cocoon of a New White Dwarf
26.04.1998

Like a butterfly, a white dwarf star begins its life by casting off a cocoon that enclosed its former self. In this analogy, however, the Sun would be a caterpillar and the ejected shell of gas would become the prettiest of all!

A Cluster Too Far
8.09.1998

Why is this galaxy cluster so red? Nearby clusters have galaxies with colors that are much more yellow and blue. A leading explanation is that this cluster of galaxies lies so far across our universe (z~1) that cosmological time dilation significantly reddens the light.

Stars from Eagles Eggs
2.05.1999

Newborn stars are forming in the Eagle Nebula. This image, taken with the Hubble Space Telescope in 1995, shows evaporating gaseous globules (EGGs) emerging from pillars of molecular hydrogen gas and dust. The giant pillars are light years in length and are so dense that interior gas contracts gravitationally to form stars.