On the Origin of Gold
11.09.2011

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.

Martian Chiaroscuro
22.03.2014

Deep shadows create dramatic contrasts between light and dark in this high-resolution close-up of the martian surface. Recorded on January 24 by the HiRISE camera onboard the Mars Reconnaissance Orbiter, the scene spans about 1.5 kilometers across a sand dune field in a southern highlands crater.

Comet Hyakutake Passes the Sun
16.05.1996

On May 1, Comet Hyakutake made its closest approach to the Sun. During this time it was not possible to view the comet with most astronomical instruments because of the brightness of the nearby Sun.

Jupiter's Auroras
18.10.1996

Auroras are especially large on Jupiter. In pictures released yesterday, the Hubble Space Telescope imaged these unusual light displays in more detail than ever before. Jupiter's auroras are linked to its volcanic moon Io.

Impact on Jupiter
28.07.1998

In 1993, a strange string of comet pieces was discovered near the planet Jupiter. So unusual a sight, Comet Shoemaker-Levy 9 (SL9) quickly became the object of much scientific curiosity. Studies showed that the Sun would soon perturb the orbit of SL9 so that it would actually

Ringside
21.10.2005

Orbiting in the plane of Saturn's rings, Dione and the other icy saturnian moons have a perpetual ringside view of the gorgeous gas giant planet. Of course, while passing through the ring plane the Cassini spacecraft also shares their stunning perspective.

A Mars Glint
8.06.1998

If aligned just right, even a planet can produce a glint. The above combined pictures of Mars make the red planet appear unusually elongated - Mars is really almost spherical. However, these pictures were taken when the Sun was nearly directly behind the Mars Global Surveyor (MGS) spacecraft.

Lightning on Earth
17.07.2000

Nobody knows what causes lightning. It is known 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.

Lightning and the Space Shuttle
9.11.1995

There are many things about lightning that are not understood. Lightning has been seen in the atmospheres of Venus, Earth, Jupiter, and Saturn. A leading theory is that collisions of particles in clouds cause large areas of positive and negative charge.

Lasers in Eta Carinae
10.01.1996

Have you heard about the great LASER light show in the sky? Well, nobody had until it was announced just yesterday by a team led by K. Davidson (U. Minnesota) and S. Johansson (U. Lund).