This image shows Meridiani Planum, the landing site for Opportunity. The yellow oval, which is 81.5 km by 11.5 km (50 by 7 miles), indicates the area within which Opportunity landed. Click on image for full size (73K JPEG) Image courtesy NASA/JPL.

The second Mars Exploration Rover (MER), named "Opportunity", landed at a site on Mars known as Meridiani Planum. This flat plain is one of the few places on Mars where the mineral gray hematite is found in large concentrations. On Earth, hematite deposits usually indicate that water was present in an area for long periods. The main goal of the MER missions is to discover and examine geologic formations that imply the presence of water at some time. Scientists chose Meridiani Planum as a MER landing site primarily because of the hematite deposits detected there.

Opportunity landed within an 81.5 km long by 11.5 km wide (50 mile by 7 mile) ellipse centered at 1.98° South latitude and 5.96° West longitude. The site is roughly on the opposite side of the Red Planet from Gusev Crater, the landing site of "Spirit", Opportunity's twin. Meridiani Planum is a flat plain ("planum" means "plain") near the prime meridian on Mars (the arbitrarily chosen location of the line of zero longitude) that offered a safe landing site for the rover to touch down. Opportunity bounced to a halt within the landing ellipse on January 24, 2004. The airbag ball Opportunity was encased within during landing actually ended up resting inside of a shallow, small crater that is about 20 meters (66 feet) across.

This picture shows Meridiani Planum, which is where Opportunity landed. The yellow oval, which is 81.5 km (50 miles) long, shows the area that Opportunity landed within. Click on image for full size (73K JPEG) Image courtesy NASA/JPL.

Two Mars Exploration Rover (MER) vehicles landed on Mars in January 2004. The second, named "Opportunity", landed at a place called Meridiani Planum. Meridiani Planum is a flat plain ("planum" means "plain"); a safe place to land! Opportunity actually ended up inside a small, shallow crater that is about 20 meters (66 feet) across.

Scientists think a mineral named gray hematite might be found at Meridiani Planum. On Earth, gray hematite usually forms in wet places. Scientists want to know whether some places on Mars used to be wet. Opportunity is looking for rocks that may have formed in wet places. That is why Opportunity landed at Meridiani Planum.

Meridiani Planum is near the equator on Mars. It is also near the Prime Meridian on Mars; that's where the name "Meridiani" comes from. The Prime Meridian is the place on a planet where the longitude is equal to zero. The Prime Meridian on Earth passes through Greenwich, England.

Opportunity is on the opposite side of the Red Planet from its twin rover, Spirit. Spirit landed at a place called Gusev Crater.

This picture shows Meridiani Planum. Opportunity landed inside the yellow oval. The oval is 81 km (50 miles) long. Click on image for full size (73K JPEG) Image courtesy NASA/JPL.

Two robot rovers landed on Mars in January 2004. They are called the Mars Exploration Rover mission. One rover is named Spirit. The other is called Opportunity. Opportunity landed at a place called Meridiani Planum.

Meridiani Planum is a very flat plain. "Planum" means "plain". Even though the plain is mostly flat, Opportunity ended up inside a crater! Don't worry - the crater is very small and the rover should be able to drive out of it.

Some minerals on Earth form in wet places. One of those minerals is called hematite. Scientists think there is hematite at Meridiani Planum. Opportunity is searching for hematite. If it finds some, that might mean that the plain used to be wet.

Opportunity has a twin. Its twin is named Spirit. Spirit landed at a different place on Mars. Spirit landed at a place called Gusev Crater.