This image shows Gusev Crater, Spirit's landing site. The yellow oval, which is 81 km by 12 km (50 by 7 miles), indicates the area within which Spirit is expected to land. The colors in this image represent elevations. Blue and green represent lower elevations, while orange and red indicate higher ground. Click on image for full size (131K JPEG) Image courtesy NASA.

The first of two Mars Exploration Rovers (MER) landed within Gusev Crater on Mars on January 3, 2004. The robotic rover, named Spirit, bounced to a halt within an 81 km by 12 km (50 by 7 miles) target landing ellipse inside the ancient crater. Once settled into its new "home", Spirit began its mission of exploring for geologic evidence of the presence of water in Gusev Crater's past.

The MER vehicles are robotic field geologists especially designed to detect rocks and soils that might indicate that liquid water was once present at their landing sites on Mars. Gusev Crater, formed by the impact of an asteroid three to four billion years ago, may have held a large lake in the distant past. A valley named Ma'adim Vallis, which is connected to the south side of the crater, looks like it may have been a river channel that poured water into the ancient lake. If that is the case, Gusev Crater should show signs of the former presence of water in its rock and soil formations.

MER mission scientists hope to find layered, sedimentary deposits indicating deposition of materials by flowing water. They are also looking for types of rocks and minerals called evaporites that form on Earth when water dries up, leaving the minerals it contains behind. For example, evaporation of salty water produces deposits of the mineral halite. Gypsum or calcium magnesian sulfate are other types of evaporites. MER is looking for carbonates (such as calcium carbonate), which also form in the presence of water and often indicate that living organisms were present. Wet environments are the best places to look for life, which is why scientists are so eager to track down places on Mars that were once wet.

Gusev Crater is about 145 km (90 miles) wide and covers an area roughly the size of the state of Connecticut. It is located at 14.6° South latitude and 175.3° East longitude on Mars. The other MER rover, Opportunity, is exploring an area on Mars named Meridiani Planum on the opposite side of the Red Planet.

This picture shows Gusev Crater, which is where Spirit landed. The yellow oval, which is 81 km (50 miles) long, shows the area that Spirit should land within. The colors in this picture show how high (or low) the land is. Low places are shown as blue and green. High places are shown as orange and red. Click on image for full size (131K JPEG) Image courtesy NASA.

The first of two Mars Exploration Rovers (MER) landed within Gusev Crater on Mars on January 3, 2004. The robotic rover is named Spirit. Spirit bounced to a halt within an 81 km by 12 km (50 by 7 miles) oval inside the ancient crater. Once settled into its new "home", Spirit began searching for rocks that might show that there used to be water in Gusev Crater.

The MER vehicles are robotic geologists. They are designed to find rocks and soils that might tell us that there once was liquid water at their landing sites on Mars. Gusev Crater formed by the impact of an asteroid three to four billion years ago. There may have been a large lake in Gusev Crater in the distant past. A valley named Ma'adim Vallis is connected to the south side of the crater. Ma'adim Vallis looks like it might have been a river that poured water into the ancient lake. If that is true, the rocks and soil in Gusev Crater should show signs that water was once there. Wet environments are the best places to look for life. That is why scientists want to find places on Mars that were once wet.

Gusev Crater is about 145 km (90 miles) wide. It is about the same size (area) as the state of Connecticut. The other MER rover, Opportunity, is exploring an area on Mars named Meridiani Planum on the opposite side of Mars.

This picture shows Gusev Crater. Spirit landed inside the yellow oval. The oval is 81 km (50 miles) long. The colors in this picture show how high (or low) the land is. Low places are shown as blue and green. High places are shown as orange and red. Click on image for full size (131K JPEG) Image courtesy NASA.

Two robot rovers landed on Mars in January 2004. The first robot is named Spirit. Spirit landed inside a big crater called Gusev Crater.

Gusev Crater may have been filled with water long ago. It may have been a big lake. Spirit is a robot geologist. Some kinds of rocks form in places where there is water. Spirit is trying to find those kinds of rocks. If it does, that might prove that Gusev Crater really was a lake.

The only water that we know about on Mars right now is frozen - it is ice! Many scientists think Mars used to be warmer. They think there may have been liquid water on Mars in the past. Liquid water is good place to find life, especially microbes. If we find water on Mars, or clues about where there used to be water, that might help us figure out whether Mars ever had life.

Spirit has a twin named Opportunity. Opportunity landed at a different place on Mars named Meridiani Planum.

Gusev Crater is about 145 km (90 miles) wide. It is about as big as the state of Connecticut. There is a valley connected to Gusev Crater. The valley looks like it might have had a river in it long ago. Maybe Spirit will find rocks that formed in water!