A Close Up of Aurora on Jupiter
19.12.2000

Jupiter has aurorae. Like Earth, the magnetic field of the gas giant funnels charged particles released from the Sun onto the poles. As these particles strike the atmosphere, electrons are temporarily knocked away from existing gas molecules. Electric force attracts these electrons back. As the electrons recombine to remake neutral molecules, auroral light is emitted.

The Compton Gamma Ray Observatory
16.01.2000

The Compton Gamma Ray Observatory (CGRO) was the most massive instrument ever launched by a NASA Space Shuttle in 1991 and continues to revolutionize gamma-ray astronomy. Before Compton loses more stabilizing gyroscopes, NASA is considering firing onboard rockets to bring it on a controlled reentry into the ocean.

Saturnian Aurora
23.12.2001

the second largest planet in the Solar System, Saturn's Rings are one of the most spectacular sights for earthbound telescopes. This image from the orbiting Hubble Space Telescope's STIS instrument, offers a striking view of another kind of ring around Saturn - pole encircling rings of ultraviolet aurora.

Tonight: A Blue Moon
30.07.1996

How often does a Full Moon occur twice in a single month? Exactly once in a Blue Moon. In fact, the modern usage of the term "Blue Moon" refers to the second Full Moon in a single month. Tonight's Blue Moon (Universal Time) will be the first since September 1993.

An Intermediate Polar Binary System
10.11.2003

How can two stars create such a strange and intricate structure? Most stars are members of multiple-star systems. Some stars are members of close binary systems where material from one star swirls around the other in an accretion disk.

Spicules: Jets on the Sun
2.08.2004

Imagine a pipe as wide as a state and as long as half the Earth. Now imagine that this pipe is filled with hot gas moving 50,000 kilometers per hour. Further imagine that this pipe is not made of metal but a transparent magnetic field.

An Intermediate Polar Binary System
21.05.2006

How can two stars create such a strange and intricate structure? Most stars are members of multiple-star systems. Some stars are members of close binary systems where material from one star swirls around the other in an accretion disk.

An Etruscan Vase Moon Rising
23.02.2009

What's happened to the Moon? Nothing, although from some locations, February's full moon, which occurred about two weeks ago, appeared strangely distorted as it rose. Visible in particular was a curiously inverted...

Flowing Barchan Sand Dunes on Mars
22.04.2012

When does Mars act like a liquid? Although liquids freeze and evaporate quickly into the thin atmosphere of Mars, persistent winds may make large sand dunes appear to flow and even drip like a liquid.

Clouds of the Carina Nebula
16.05.2016

What forms lurk in the mists of the Carina Nebula? The dark ominous figures are actually molecular clouds, knots of molecular gas and dust so thick they have become opaque. In comparison, however, these clouds are typically much less dense than Earth's atmosphere.