JPL
Careers
Education
Science & Technology
JPL Logo
JPL Logo
Image

Schematic of Mars Interior

Oct. 14, 1997
The interior of Mars is simply modeled as a core and mantle with a thin crust, similar to Earth. The combination of NASA's Mars Pathfinder Doppler data with earlier data from the Viking landers determined a third parameter, the moment of inertia.

The interior of Mars is simply modeled as a core and mantle with a thin crust, similar to Earth. Mars' size and total mass have been determined by previous missions. Given four parameters, the core size and mass, and mantle size and mass can be determined. The combination of Pathfinder Doppler data with earlier data from the Viking landers has determined a third parameter, the moment of inertia, through measurement of Mars' precession rate. A fourth measurement is needed to complete the interior model. This may be achieved through future Doppler tracking of Pathfinder, since the presence of a fluid core may be detectable through its effect on Mars' nutation. The determination of the moment of inertia is a significant constraint on possible models for Mars' interior. If the core is as dense as possible (i.e. completely iron) and the mantle is similar to Earth's (or similar to the SNC meteorites thought to originate on Mars) then the minimum core radius is about 1300 km. If the core is made of less-dense material (i.e. a mixture of iron and sulfur) then the core radius is probably no more than 2000 km.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Photojournal note: Sojourner spent 83 days of a planned seven-day mission exploring the Martian terrain, acquiring images, and taking chemical, atmospheric and other measurements. The final data transmission received from Pathfinder was at 10:23 UTC on September 27, 1997. Although mission managers tried to restore full communications during the following five months, the successful mission was terminated on March 10, 1998.

Download JPG
Download TIFF
Mission
Target
  • Mars
Spacecraft
  • Mars Pathfinder Lander
Instrument
  • Deep Space Network
Credit
NASA/JPL

Keep Exploring

Slice of History - Happy 25th Anniversary, Mars Pathfinder!

Three Generations of Rovers with Crouching Engineers

Three Generations in Mars Yard, High Viewpoint

Three Generations of Rovers in Mars Yard

Three Generations of Rovers with Standing Engineers

Sunset on Mars from Pathfinder Images

Pathfinder Spies Dust Devils

Delta Rocket Launch Carrying Mars Pathfinder

Sojourner Latch Spring Deployed

First IMP Image

Related Topic

Mars .

Media Teleconference - May 17, 2022

News .

NASA’s InSight Still Hunting Marsquakes as Power Levels Diminish

News .

NASA to Provide Update on InSight Mars Lander

News .

NASA’s InSight Records Monster Quake on Mars

News .

Science at Sunrise: Solving the Mystery of Frost Hiding on Mars

News .

NASA’s Mars Helicopter Scouts Ridgeline for Perseverance Science Team

News .

NASA’s Mars Helicopter Spots Gear That Helped Perseverance Rover Land

News .

NASA Extends Exploration for 8 Planetary Science Missions

News .

NASA’s Perseverance Rover Captures Video of Solar Eclipse on Mars

News .

NASA’s Perseverance Rover Arrives at Delta for New Science Campaign

About JPL
Who We Are
Executive Council
Directors
Careers
Internships
The JPL Story
JPL Achievements
Documentary Series
Annual Reports
Missions
Current
Past
Future
All
News
All
Earth
Solar System
Stars and Galaxies
Subscribe to JPL News
Galleries
Images
Videos
Audio
Podcasts
Apps
Visions of the Future
Slice of History
Robotics at JPL
Events
Lecture Series
Team Competitions
Speakers Bureau
Calendar
Visit
Public Tours
Virtual Tour
Topics
JPL Life
Solar System
Mars
Earth
Climate Change
Exoplanets
Stars and Galaxies
Robotics
More
Asteroid Watch
NASA's Eyes Visualizations
Universe - Internal Newsletter
Social Media
Get the Latest from JPL
Follow Us

JPL is a federally funded research and development center managed for NASA by Caltech.

More from JPL
Careers Education Science & Technology Acquisitions JPL Store
Careers
Education
Science & Technology
Acquisitions
JPL Store
Related NASA Sites
Basics of Spaceflight
Climate Kids
Earth / Global Climate Change
Exoplanet Exploration
Mars Exploration
Solar System Exploration
Space Place
NASA's Eyes Visualization Project
Voyager Interstellar Mission
NASA
Caltech
Privacy
Image Policy
FAQ
Feedback
Site Managers: Veronica McGregor, Randal Jackson
Site Editors: Tony Greicius, Naomi Hartono