Sojourner
A "sojourner" is someone who stays only temporarily in a place - and that was what the Sojourner satellite did! Officially named for the 19th century civil rights advocate Sojourner Truth, the Sojourner rover was the first to explore the surface of Mars during the three months before its equipment failed.
Sojourner on Pathfinder's platform
Image Credit: NASM
Sojourner on Mars, touching "Yogi" rock
Image Credit: NASA/JPL
When was Sojourner launched?
Sojourner was launched in the Mars Pathfinder Lander on December 4th, 1996 and landed on Mars on July 4th, 1997. Sojourner successfully operated for almost three months. Sojourner's final data transmission was received on September 27, 1997.
What was Sojourner's mission?
Sojourner mission was largely to demonstrate new technology. NASA scientists wanted to prove that they could send scientific instruments to another planet quickly and at a relatively low cost. While on Mars, Sojourner explored an area of the planet called Ares Vallis and studied Martian rocks, dirt, and weather factors such as wind.
What was special about Sojourner?
Sojourner was the first Rover on Mars, and it sent back more than 550 images of Mars to Earth.
The ridges on and valleys on this rock might have been shaped by strong winds over a long period of time. What is this process called?
Image Credit: NASA/JPL
This rock has a pitted texture that might have been caused by volcanic, sedimentary, or weathering processes. Can you think of similar look rocks on Earth?
Image Credit: NASA/JPL
The surface of Mars isn't all hard rocks. In this picture, we can see the tracks Sojourner left behind in a softer patch of soil. How might this softer soil change over time?
Image Credit: NASA/JPL
How do these images help us learn about Mars?
Using satellites and high powered telescopes, Mars looks cold, dry, and rocky. Using the up close pictures from Sojourner, scientists learned that in the past, Mars might have been a much warmer and wetter place.
What do these images tell us about the terrain on Mars?
The area Sojourner explored might be the site of an ancient flood. It is fairly flat, but has many different types of rocks including rounded pebbles that would have formed in running water. The textures of the rocks suggests that they were shaped over time by wind. Clues like these help scientists learn about how Mars has changed over time, and what its ancient climate and terrain might have been like.
Use your mouse or mobile device to explore Sojourner's landing site in 360 degrees!