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Ready, Set, SCIENCE!, by the National Research Council, focuses on K-8 science classsrooms. Check out the other publications in our online store, as well as classroom materials.
The interior of Mars as deduced by Mars Pathfinder.
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Image from: NASA/JPL

The Interior of Mars, from Mars Pathfinder

Many missions have returned data on the shape of Mars. These data first showed that Mars had a bulge, now called the Tharsis Ridge. Mars Pathfinder took better data data on the shape of Mars, and a more accurate measurement of the Polar Moment of Inertia, which contributes to an understanding of a planet's interior structure.

These data suggest that Mars has a large 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.

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Our online store includes issues of NESTA's quarterly journal, The Earth Scientist, full of classroom activities on different topics in Earth and space science, ranging from seismology, rocks and minerals, oceanography, and Earth system science to astronomy!

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Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF