The interior of Mars as deduced by Mars Pathfinder.
Click on image for full size
Image from: NASA/JPL

The Interior of Mars, from Mars Pathfinder

Many missions have returned data on the shape of Mars, a measurement which contributes to an understanding of a planet's interior structure. These data first showed that Mars had a huge bulge, now called the Tharsis Ridge. Mars Pathfinder took better data on the shape of Mars by passing over the Martian poles instead of the around the middle.

These data suggest that Mars has a large, and solid core, as shown in the figure to the left. (The figure is a rough drawing and is not meant to show the detailed shape of the core). These findings help address questions which remain about Mars, and contribute to the overall results returned by the Mars Pathfinder mission.

Scientists used to think that because the Martian surface contained so much iron, and the Martian magnetic field was weak, that the early history of Mars was not sufficiently warm for Mars to differentiate, and form a large solid iron core, such as that of the Earth. A large molten iron core would generate a strong magnetic field. Thus, iron must have stayed mostly on the outside layers of Mars, making the surface red with rust.

Recently, Mars Global Surveyor returned the first definitive measurement of a Martian magnetic field. Therefore, if the core of Mars is large and composed of iron as the Mars Pathfinder measurement shows, then this theory about the evolution of Mars may not be completely correct.


You might also be interested in:

Cool It! Game

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

How do we know what the inside of a Planet or Moon is like?

You may wonder how it is that scientists know what the inside of a planet is like. The interior of a moon or planet can be closely determined from spacecraft navigation data when a spacecraft passes by...more

Results from Mars Pathfinder

These are the findings of Mars Pathfinder. Rounded Pebbles, Cobbles and possible Conglomerates were found - a result from analysis of the landing site, the rocks, and the soils. showed that there were...more

Differentiation

Differentiation is a scientific term which really means "to separate". In their earliest history, elements which made the planets would part into separate regions, if the planet were warm enough. This...more

Mars Global Surveyor Magnetometer findings

An important new result from the Mars Global Surveyor (MGS) mission is the definite confirmation of the presence of a magnetosphere around Mars. Previous missions did not make really good measurements...more

Mars Odyssey

The Mars Odyssey was launched April 7, 2001, from Florida. After a six-month, 285 million-mile journey, the Odyssey arrived at Mars on October 24, 2001. The Odyssey is in its aerobraking phase right now....more

Mars 2005

The Mars 2005 mission is still in the planning stages. It is set to launch in the year 2005. ...more

Aerobraking

The Mars Global Surveyor reached Mars in September of 1997. But it didn't make it into its final mapping orbit until February 1999. What took so long? Surveyor needed to reach a near-circular, low-altitude...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA