Dark Volcano Active on Io
10.11.1997

The surface of Io is changing even as we watch. The inset frame of Jupiter's most active moon was taken by the robot spacecraft Galileo in April. Just last month the larger image was taken. The new large black spot reveals that a volcano named Pillan Patera has been erupting during the interim.

Sizzling Io
6.07.1998

What's cooking on Io? This active moon of Jupiter is marked with volcanoes spewing lava that is now known to be hotter than any lava on Earth. Above is the highest resolution color-enhanced image yet composed of the most active surface in our Solar System. Features as small as three kilometers are visible.

Io: Moon Over Jupiter
6.07.2002

Io's Giant Volcano Pele
5.12.1996

Io has some very large volcanoes. One of the largest is evident near the center of the above photograph and named Pele, for the mythological Polynesian fire goddess. The Galileo spacecraft now orbiting Jupiter took this picture of Jupiter's most active moon in June, although it was released just last week.

Io's Active Volcanoes
27.10.1996

Why is Io green at night? In this just-released nighttime picture of Jupiter's moon Io, the red spots clearly show Io's current volcanically active regions. But what is causing the global green sheen? This telling picture was taken by the automated Galileo spacecraft currently orbiting Jupiter while Io was in Jupiter's shadow.

Jupiter, Io, and Ganymede's Shadow
13.10.1995

Jupiter, the solar system's largest planet, is seen here next to Io, its closest Galilean moon. On the cloud tops of Jupiter near the left edge of the picture can be seen a dark circular spot which is caused by the shadow of Jupiter's largest moon Ganymede.

Io: A Volcanic Moon
3.08.1995

In 1610, Galileo turned his telescope to the heavens and discovered that the planet Jupiter had four bright moons. The innermost of these Galilean moons, Io, turned out to be one of the most exotic objects in the solar system.

Lava Fountain on Jupiter's Io
20.12.1999

A lava fountain shooting over a kilometer high has been discovered on Jupiter's moon Io. The robot Galileo spacecraft orbiting Jupiter photographed the volcanic eruption during its close flyby of the moon late last month. The fountain is visible in the above mosaic of images from the flyby.

Eruption on Io
23.06.1997

There it goes again. Gas and rock were catapulted hundreds of kilometers into space as Jupiter's most volatile moon, Io, showed yet another impressive volcanic display in this just-released photograph by the Hubble Space Telescope.

Io at Sunset
20.01.2003

How tall are mountains on Jupiter's moon Io? One way to find out is to view them at sunset. Tall structures facing the Sun are then better-lit and cast long shadows. The above...