Shop Windows to the Universe

Science, Evolution, and Creationism, by the National Academies, focuses on teaching evolution in today's classrooms. Check out the other publications in our online store.
This image illustrates the magnetic field of the planet.
Click on image for full size
Image from: NASA/JPL

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 made inconclusive measurements of the Martian magnetic field. A determination of the presence of a magnetic field helps scientists understand where the magnetic material of Mars resides, and a little bit about the Martian evolution. It also answers one fundamental question set to be resolved by the Mars Surveyor Program.

Scientists used to think that because the Martian surface contained so much iron, and the Martian magnetic field was so weak, that the early history of Mars was not sufficiently warm for Mars to differentiate, and form a large solid iron core. A large molten iron core, such as that of the Earth, 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 Pathfinder returned a measurement which suggested that Mars has a large iron core. Therefore, if the core of Mars is large and composed of iron as the Mars Pathfinder measurement shows, and there definitely is a magnetic field generated inside as the Mars Global Surveyor measurement shows, then this theory about the evolution of Mars may not be completely correct.

Last modified June 3, 2003 by Randy Russell.

Shop Windows to the Universe Science Store!

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, as well as books on science education!

Windows to the Universe Community



You might also be interested in:

Traveling Nitrogen Classroom Activity Kit

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

The Martian Magnetosphere

An important new result from the Mars Global Surveyor (MGS) mission is the definite confirmation of the presence of a magnetic field near Mars. The magnetic field leads to the formation of a magnetosphere,...more

The Mars Surveyor Program

Born as a result of the failure of Mars Observer (MO), the Mars Surveyor Program was designed to explore Mars with all the original measurements planned for MO, and a lot more. It varied from the MO mission...more


Differentiation is a scientific term which really means "to separate". In their earliest history, elements which comprised the planets and moons would part into separate regions, if the body was warm enough....more

The Martian Ionosphere

The Martian ionosphere is a layer of gas composed of ions and electrons that extends from about 75 miles up to several hundred miles up above the surface. The layer is shown schematically by the shaded...more

Instruments of the Mars Global Surveyor Mission

Mars Global Surveyor (MGS) is conducting mapping operations at Mars more than 30 years after America's first reconnaissance missions reached the mysterious red planet. Here are some of the instruments...more

Initial Mars Global Surveyor Findings

These are some of the initial findings of Mars Global Surveyor. The definite confirmation of the presence of a magnetic field near Mars. suggests scientists must rethink theories about the evolution of...more

Detecting Planetary Magnetism

A magnetometer is an instrument for measuring magnetic fields. Many spacecraft carry magnetometers to measure the magnetic fields around planets they orbit or fly by. When a spacecraft takes such measurements,...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