Ganymede

Jupiter III

Table of Contents

• Ganymede (This page)
  • Ganymede Statistics
  • Animation of Ganymede
  • Views of Ganymede
• Hubble Finds Ozone on Jupiter's Moon Ganymede

Ganymede [GAN-ee-meed] is the largest moon of Jupiter and is the largest in our solar system with a diameter of 5,262 km (3,280 miles). Like Callisto, Ganymede is most likely composed of a rocky core with a water/ice mantle and a crust of rock and ice. It has no known atmosphere. It has mountains, valleys, craters and lava flows. Ganymede is mottled by both light and dark regions. It is heavily cratered especially in the dark regions implying ancient origin. The bright regions show a different kind of terrain - one which is grooved with ridges and troughs. These features form complex patterns and have a vertical relief of a few hundred meters and run for thousands of kilometers. The grooved features were apparently formed more recently than the dark cratered area perhaps by tension from global tectonic processes. The real reason is unknown; however, local crust spreading does appear to have taken place causing the crust to shear and separate.

Ganymede Statistics

Discovered by ................ Simon Marius & Galileo Galilei
Date of discovery ...................................... 1610

Mass (kg) .......................................... 1.48e+23
Mass (Earth = 1) ................................. 2.4766e-02
Equatorial radius (km) ................................ 2,631
Equatorial radius (Earth = 1) .................... 4.1251e-01
Mean density (gm/cm^3) ................................. 1.94

Mean distance from Jupiter (km) ................... 1,070,000
Rotational period (days) ........................... 7.154553
Orbital period (days) .............................. 7.154553
Mean orbital velocity (km/sec) ........................ 10.88

Orbital eccentricity .................................. 0.002
Orbital inclination ................................... 0.195°

Escape velocity (km/sec) ............................... 2.74

Visual geometric albedo ................................ 0.42
Magnitude (Vo) ......................................... 4.61

Animation of Ganymede

• Flight over Ganymede - AVI, 3.3M. (Courtesy NASA/JPL)

Views of Ganymede

Ganymede (GIF, 187K)
This shows an entire hemisphere of Ganymede. The prominent dark region, called Galileo Regio, is about 3,200 km in diameter. The bright spots are relative recent impact craters. Part of the Galileo Regio may be covered with a bright frost. (Credit: Calvin J. Hamilton, and NASA)

Southern Galileo Regio (GIF, 400K)
This image of southern Galileo Regio shows impact craters in various stages of degradation. Almost all of the craters appear flat. The two prominent light colored craters are almost completely erased by the flow in the icy crust. (Credit: Calvin J. Hamilton, and NASA)

Impact Crater (GIF, 434K; GIF, 2M)
This mosaic of high resolution images on Ganymede shows a relative fresh impact basin surrounded by ejecta. (Credit: Calvin J. Hamilton, and NASA)

Jupiter Europa Callisto

Author: Calvin J. Hamilton