(spacer graphic)

Kid's Tour to Mars

Sojourner Rover

Look Up a Word in the Glossary

Return to Start of Kids Tour to Mars

Kids Tour to Mars Site Map

Back one pageForward One Page

Forward one page
Back to Mars Pathfinder
Click for Mars Pathfinder Mission
(You are here)


Robots on Mars

After the Mars Pathfinder landed in July, 1997 it began a successful mission exploring Mars with on-board instruments and the robot Sojourner rover. The rover, named Sojourner after American civil rights crusader Sojourner Truth, is 65 centimeters (2 feet) long, 48 centimeters (1.5 feet) wide and 30 centimeters (1 foot) tall. On Earth it weighed 10.5 kilograms (23 pounds) but on Mars weighed only 4 kilograms (8.8 pounds) due to the difference in the size of the two planets. The robot carried a device called an Alpha Proton X-ray Spectrometer used to test soil and rock samples to determine what minerals were present.

Sojourner rover tests the rock called Moe
In the descriptions below from NASA/JPL the Sol dates refer to Mars "days" to distinguish them from Earth days.

This color image (left) shows the Sojourner rover's Alpha Proton X-ray Spectrometer (APXS) deployed against the rock "Moe" on the morning of Sol 65. The rock behind the rover is "Half Dome", which was previously measured by the APXS.
(Image Description by NASA/JPL)


Half Dome Rock Half Dome Rock > > >  
"This image of the rock "Half Dome" was taken by the Sojourner rover's left front camera on Sol 71 (September 14). Pits, linear textures, and pronounced topography on the rock are clearly visible."
(Image Description by NASA/JPL)

Half Dome rock is about the size of the rover. In the lower left corner a rover track is visible.

Sojourner rover on the rock called Wedge
(Image Description

< < < Wedge
"This image taken on Sol 44 shows the Sojourner rover with its left front and middle wheels perched on the rock "Wedge". The rover's Alpha Proton X-ray Spectrometer (APXS) is the cylindrical object extending from the back of the rover."

Using the Alpha Proton X-ray Spectrometer (APXS), it takes about 10 hours for a full study of a sample to determine its composition. The APXS bombards the sample with alpha particle radiation. Alpha particles are the nucleus of a Helium atom. The studies showed that Mars and Earth are made up of similar material, such as andesite from volcanic activity and basaltic igneous rock.

Rover view of lander, click for diagramThe image at right is the rover's view of the lander showing the deflated airbags, ramps and solar panels. The dark circle is the NASA logo on the side of the lander.
Click on image for a detail view.

All external links open in a new tab.
Close the tab to return to Kid's Cosmos.

NASA Mars Missions

Mars Pathfinder
Sojourner Rover
Viking, Pathfinder and other Mars missions

Back one page Forward one page Go back a page or continue on to next page.

Geology Terms

Here are some basic terms used in the tour. Find more geology terms in the Glossary.

Volcanic igneous rock related to granite.
Ares Vallis
Area of Mars where the Mars Pathfinder and Sojourner Rover landed.
Volcanic rock caused by partial melting of the Earth's crust.
A smooth plain covered by deposits of sand, gravel and rocks from floods. Sharp-edged rocks have only been carried by floodwaters a short distance while smooth, rounded rocks have traveled long distances.
Coarse-grained igneous rock usually without obvious bands or markings.
Igneous Rock
Rock that has been melted, cooled and become solid.
Metamorphic Rock
Rocks that have changed form through high pressure and heat. Examples are marble, gneiss and slate.
Weathered rocks, gravel, soil and such that covers bedrock.
Sedimentary Rock
Rock formed by pressure and accumulation, e.g., lakebeds changed into rock form loose sand, silt and organic materials.
A vent at the surface where magma, gas and steam erupt. Also, the landform constructed by volcanic material.

Kids' Cosmos… Expanding Minds Beyond the Limits of the Universe

(divider bar)

Kid's Cosmos
P.O. Box 14077, Spokane, WA 99206-4077
© 2011 Kid's Cosmos

This tour created with the support of:

Film and Developing provided by Rite Aid www.webmaker-nw.com www.runway.net

© 2011 Kid's Cosmos
Kid's Cosmos