Dione's Lagrange Moon Helene
10.10.1995

Saturn's moon Helene is very unusual in that it circles Saturn near the orbit of a bigger moon: Dione. Helene is situated in what is called a "Lagrange point" of Dione - a place of stability created by Dione's gravity.

Venus: Just Passing By
25.06.2005

Venus, the second closest planet to the Sun, is by far the brightest of the three planets gathered in this weekend's western sky at sunset. It has also proven to be a popular way-point for spacecraft headed for the gas giant planets in the outer reaches of the solar system. Why visit Venus first?

Galaxy Wars: M81 versus M82
25.03.2008

On the left, surrounded by blue spiral arms, is spiral galaxy M81. On the right marked by red gas and dust clouds, is irregular galaxy M82. This stunning vista shows these two mammoth galaxies locked in gravitational combat, as they have been for the past billion years.

Jupiter's Inner Moons
27.11.1997

The potato-shaped inner moons of Jupiter are lined-up in this mosaic "family portrait" of these tiny Jovian satellites. The individual images were recorded over the last year by NASA's Galileo spacecraft and are scaled to the moons' relative sizes.

Venus: Just Passing By
29.09.2002

Venus, the second closest planet to the Sun, is a popular way-point for spacecraft headed for the gas giant planets in the outer reaches of the solar system. Why visit Venus first? Using...

A Total Eclipse of the Sun
11.03.1998

On February 26th, it was dark during the day. This total solar eclipse was the last visible from the Americas for this millennium. A total solar eclipse is exciting partly because it is so short.

Venus: Just Passing By
1.05.1998

Venus, the second closest planet to the Sun, is a popular way-point for spacecraft headed for the gas giant planets in the outer reaches of the solar system. Why visit Venus first? Using...

Sgr A: Fast Stars Near the Galactic Center
20.12.2000

Why are these stars moving so fast? Shown above is a time-lapse movie in infrared light detailing how stars in the central light-year of our Galaxy have moved over the past eight years. The yellow mark at the image center represents the location of a peculiar radio source named Sgr A

Galaxy Wars: M81 Versus M82
9.02.2000

In the left corner, wearing a red nucleus surrounded by blue spiral arms, is M81. In the right corner, sporting light stars and dark dust lanes, is M82. These two mammoth galaxies have been locked in gravitational combat for the past billion years.

Sonified: The Matter of the Bullet Cluster
16.12.2020

What's the matter with the Bullet Cluster? This massive cluster of galaxies (1E 0657-558) creates gravitational lens distortions of background galaxies in a way that has been interpreted as strong evidence for the leading theory: that dark matter exists within.