An artist's rendition of the Mars Express spacecraft approaching Mars. The round, copper-colored object near the top of the spacecraft is the Beagle 2 lander.
Click on image for full size
Image courtesy European Space Agency (ESA) - Illustration by Medialab

Overview of the Mars Express Mission

The European Space Agency (ESA) launched a mission to Mars called "Mars Express" in June of 2003. The Mars Express spacecraft has two parts: an orbiter that will circle Mars for at least one Martian year (687 Earth days), and a lander named "Beagle 2" which is scheduled to touch down on the surface of the Red Planet on December 25, 2003.

One of the orbiter's main purposes is to search for water beneath the surface of Mars using a radar system called MARSIS (Mars Advanced Radar for Subsurface and Ionospheric Sounding). Scientists are very curious as to whether there might be life on Mars, and water deposits are a good place to look for living creatures. The surface of Mars is too cold and dry for water, but there may be water underground in aquifers. The Mars Express orbiter will also take high-resolution images to map Mars, will study the atmosphere of Mars, and will produce maps of the distribution of minerals on the surface of Mars.

Beagle 2 will land at a site named "Isidis Planitia" just north of the Martian equator. Isidis Planitia is a flat plain within an ancient impact crater that may once have contained a lake. The main chore of the Beagle 2 is to search for signs of life. Beagle 2 is not a rover, so it will only be able to examine the ground immediately around its landing site. It will scoop up samples of soil with a Position Adjustable Workbench (PAW) at the end of its robotic arm and chemically analyze those samples. Scientists hope Beagle 2 will find compounds that indicate the presence of living organisms. They will also analyze the mineral contents of the soil samples. ESA mission planners hope that Beagle 2 will be able to survive and conduct investigations on Mars for about six months.

Beagle 2 is named after the ship, the H.M.S. Beagle, which Charles Darwin sailed on shortly before he wrote his famous book about evolution and natural selection titled "On the Origin of Species". Darwin's book had a tremendous impact on our understanding of living creatures and profoundly influenced the science of biology. The scientists who planned the Mars Express mission hope to find signs of life on Mars, which would also be an important breakthrough in biology, so they named their lander after Darwin's ship.

Last modified December 29, 2003 by Randy Russell.

You might also be interested in:

Ready, Set, SCIENCE!: Putting Research to Work in K-8 Science Classrooms

What types of instructional experiences help K-8 students learn science with understanding? What do science educators teachers, teacher leaders, science specialists, professional development staff, curriculum designers, school administrators need to know to create and support such experiences?...more

Exploratour: Life on Mars?

When we ask "Where might we find extraterrestrial life", the first place many scientists turn to, because of its similarity to the Earth, is Mars. Mars is the closest analog to the Earth in both the present...more


Most of the water we are aware of is in ponds, rivers, oceans, streams, lakes, puddles, and other places on top of the ground. What we donít see is the water that soaks into the ground. Water that has...more

Lower Atmosphere

The atmosphere of Mars is much thinner than that of Earth, with a surface pressure averaging 1/100th that at the surface of the Earth. Surface temperatures range from -113oC at the winter pole to 0oC...more

Martian Cratered Terrain

This is an example of the cratered terrain on Mars. Almost the entire surface of Mars is cratered to various degrees. The Tharsis Ridge, where the volcanoes of Mars are located, is lightly cratered. The...more

Charles Darwin

Charles Darwin was an English Naturalist who lived between 1809-1882. In 1859, with the publication of The Origin of Species by Means of Natural Selection, he challenged existing views on the appearance...more

The Exploration of Mars

In the past few decades, the Russian and American space agencies have sent many spacecraft to Mars. Some have been a great success while others didn't even make it into space! In 1998, Japan also joined...more

ACE Launch

The Advanced Composition Explorer (ACE) was launched at 10:39 a.m., August 25, 1997.The ACE was launched aboard a Delta II rocket. Mission lifetime is expected to be two years for the primary mission with...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