PIA00078: Gaspra, Deimos, and Phobos Comparison


Gaspra, Deimos, and Phobos Comparison

Caption:

This montage shows asteroid 951 Gaspra (top) compared with Deimos (lower left) and Phobos (lower right), the moons of Mars. The three bodies are shown at the same scale and nearly the same lighting conditions. Gaspra is about 17 kilometers (10 miles) long. All three bodies have irregular shapes, due to past catastrophic conditions. However their surfaces appear remarkably different, possibly because of differences in composition but most likely because of very different impact histories. The Phobos and Deimos images were obtained by the Viking Orbiter spacecraft in 1977; the Gaspra image is the best of a series obtained by the Galileo spacecraft on October 29, 1991. Galileo is scheduled to add the detailed view of another asteroid when it flies by Ida in August 1993.

Background Info:

The Galileo project, whose primary mission is the exploration of the Jupiter system in 1995-97, is managed for NASA's Office of Space Science and Applications by the Jet Propulsion Laboratory.

Cataloging Keywords:

Name Value Additional Values
Target 951 Gaspra Jupiter, Mars
System Asteroid Belt Jupiter, Mars
Target Type Planet Asteroid
Mission Galileo Viking
Instrument Host Galileo Orbiter
Host Type Orbiter
Instrument Solid-State Imaging (SSI)
Detector
Extra Keywords Grayscale
Acquisition Date
Release Date 1996-01-29
Date in Caption 1991-10-29
Image Credit NASA/JPL
Source photojournal.jpl.nasa.gov/catalog/PIA00078
Identifier PIA00078