Kepler Discovers How Planets Move
6.06.1999

Johannes Kepler used simple mathematics to describe how planets move. Kepler was an assistant to the most accurate astronomical observer of the time, Tycho Brahe. Kepler was able to use Brahe's data...

Kepler Discovers How Planets Move
14.01.2001

Johannes Kepler used simple mathematics to describe how planets move. Kepler was an assistant to the most accurate astronomical observer of the time, Tycho Brahe. Kepler was able to use Brahe's data...

Slightly Beneath Saturns Ring Plane
5.04.2006

When orbiting Saturn, be sure to watch for breathtaking superpositions of moons, rings, and shadows. One such picturesque vista was visible recently to the robot Cassini spacecraft now orbiting Saturn. In late February, Cassini captured a Rhea, the second largest moon of Saturn, while looking up from slightly beneath Saturn's expansive ring plane.

Discovery in Motion
8.07.2006

On July 4th, the space shuttle orbiter Discovery rocketed into space on mission STS-121. Now docked with the International Space Station, Discovery orbits planet Earth at about 27 thousand kilometers per hour.

The Four Suns of HD 98800
30.07.2007

How would it look to have four suns in the sky? Planets of the HD 98800 system, if they exist, would experience such a view. HD 98800 is a multiple star system about 150 light years from Earth -- right in our section of the Milky Way Galaxy.

A Star Cluster in Motion
30.07.2002

Star clusters are a swarm of complex motions. The stars that compose globular clusters and many open clusters all orbit the cluster center, occasionally interacting, gravitationally, with a close-passing star. The orbits of stars around the cluster are typically not as circular as the orbits of planets in our solar system.

A Wavemaker Moon in Saturns Rings
23.05.2005

What causes small waves in Saturn's rings? Observations of rings bordering the Keeler gap in Saturn's rings showed unusual waves. Such waves were first noticed last July and are shown above in clear detail.

Irregular Moons Discovered Around Uranus
3.11.1997

Where did these two irregular moons of Uranus originate? Last week two previously undiscovered moons of the distant gas planet were confirmed, the first in irregular orbits. All fifteen previously known moons of Uranus are 'regular', circling near the planet's equator. Most of these were discovered by the passing Voyager 2 spacecraft in 1986.

Earthset from Orion
20.11.2024

Eight billion people are about to disappear in this snapshot from space taken on 2022 November 21. On the sixth day of the Artemis I mission, their home world is setting behind the Moon's bright edge as viewed by an external camera on the outbound Orion spacecraft.

Mars in the Loop
8.11.2018

This composite of images spaced some 5 to 9 days apart, from late April (bottom right) through November 5 (top left), traces the retrograde motion of ruddy-colored Mars through planet Earth's night sky.