The Opportunity Rover is the second of two vehicles the National Aeronautics and Space Administration (NASA) monitors as they explore the surface of Mars. This rover landed on the surface of Mars 25 January 2004 on a mission that was intended to last 90 sols, or Martian days, which is approximately 92.46 Earth days. Both Opportunity, and its sister rover, Spirit, were in service well past that goal, with exploration continuing over five years later.
The primary mission of both the Opportunity rover and its sister, Spirit, is to give a detailed account of Mars' surface. Understanding the makeup of the surface can help scientists to set a time line for the creation of the planet, and thereby give more evidence towards theories about the creation of the solar system. Much as rock beds on Earth can reveal areas that once held swamps, one hope was to use rock and mineral deposits to discover if water, and even perhaps life, had existed on Mars at one point in time.
The Opportunity rover has six wheels to increase its stability as it rolls over the rocky Martian surface. It receives power from solar panels on its exterior, and uses rechargeable lithium ion batteries that help it stay powered during the evenings. Opportunity communicates with Earth through a set of two antenna. The rover is outfitted with two cameras: a panoramic camera to examine the local landscape, and a navigational camera to assist in driving the vehicle. A miniature Thermal Emission Spectrometer, or Mini-TES, is able to get a close-up look at rock and soil and determine how it was formed.
The Opportunity rover also has an arm outfitted with a wide array of instruments that assist in research. A Mössbauer Spectrometer examines rocks and minerals closely. Magnets are used to pick up any dust that may contain metallic properties. A Rock Abrasion Tool breaks through layers of rock to show fresh material below the surface. An Alpha Particle X-ray Spectrometer can give analysis of the elements inside rock and soil. Finally, a Microscopic Imager gives detailed close-up images of the rock and soil.
The extended usability of the rovers has allowed scientists to go far beyond their initial plans for exploration. The Opportunity rover has investigated the Eagle Crater, the Heat Rock Shield, Endurance Crater, Erebus Crater and Victoria Crater among other areas. It has taken countless panoramic images of Mars' surface, giving invaluable first hand accounts of the makeup of the planet. Opportunity has shown significant proof of past water on the red planet, as well as provided new information about the makeup of Mars and the surrounding atmosphere.