National Aeronautics and Space Administration Logo
Follow this link to skip to the main content NASA Banner
Small Worlds, Big Discoveries Banner

Goals: While en route to its primary science mission at Jupiter, Galileo's mission team used two fortunate encounters with asteroids as bonus science opportunities and equipment tests for the Jupiter orbital mission.

Accomplishments:In 1991, Galileo passed the asteroid 951 Gaspra at a
distance of 1,600 kilometers (1,000 miles). Galileo found that Gaspra is an irregular object (19 by 12 by 11 kilometers), which lacks the large craters common on many planetary satellites.

In 1993, Galileo had crossed paths with asteroid 243 Ida, at a distance
of 2,400 kilometers (1,500 miles). Much to everyone's surprise, Galileo
images showed a tiny moon orbiting Ida - the first known moon of asteroid. Dactyl, about
1.5 kilometers in diameter, orbits about 100 kilometers (62 miles) from Ida's center.

Banner says visit the Galileo Legacy Site
Key Dates
18 Oct 1989:  Launch (16:53:40 UT)
7 Dec 1995:  Probe Descent (22:04 UT - 23:02 UT)
21 Sep 2003:  Jupiter Impact (18:57:18 UT)
Status: Successful
Fast Facts
Galileo Facts Galileo was launched from the Space Shuttle Atlantis.

The spacecraft traveled more than 4.6 billion km (about 2.8 billion miles) during its 14-year mission.

Galileo was named in honor of Galileo Galilei (above), who discovered the largest moons of Jupiter in 1610.

The spacecraft was the first to orbit a gas giant planet.

Galileo plunged into Jupiter's crushing atmosphere on Sept. 21, 2003. The spacecraft was deliberately destroyed to protect one of its own discoveries - a possible ocean beneath the icy crust of the moon Europa.
Science & Technology Features
People Spotlight
James Green James Green
"I view my job as the keeper of NASA's planetary program and the top advocate for that program to flourish and grow." Read More...

Awards and Recognition   Solar System Exploration Roadmap   Contact Us   Site Map   Print This Page
NASA Official: Kristen Erickson
Advisory: Dr. James Green, Director of Planetary Science
Outreach Manager: Alice Wessen
Curator/Editor: Phil Davis
Science Writer: Autumn Burdick
Webmaster: David Martin
> NASA Science Mission Directorate
> Budgets, Strategic Plans and Accountability Reports
> Equal Employment Opportunity Data
   Posted Pursuant to the No Fear Act
> Information-Dissemination Policies and Inventories
> Freedom of Information Act
> Privacy Policy & Important Notices
> Inspector General Hotline
> Office of the Inspector General
> NASA Communications Policy
> NASA Advisory Council
> Open Government at NASA