by: Nicole Willett
June 21, 2013 was a big day for Opportunity as she passed five Martian years roving Mars. On January 25, 2014 the Opportunity rover will have completed 10 full Earth years on Mars. This is an amazing achievement, considering the Opportunity Rover was only a 90 day mission. Since the 9th anniversary, Opportunity has left Cape York and discovered an area where neutral pH water once was. This is further evidence of habitability on the Red Planet. Opportunity then drove to Solander Point in order to drive on a terrain that has a slope pointing toward the sun for the best winter time sunlight collection. For now Opportunity is on the edge of Endeavor Crater spying interesting minerals as we anxiously await her next amazing discovery.
In honor of Opportunity and her twin, Spirit, a new museum exhibit has opened at the Smithsonian Institution. Huge wall size panoramas of Mars give visitors a sense that they are on the surface of the planet. The exhibit also has a full scale model of the rover as its centerpiece. The name of the exhibit is “Spirit and Opportunity: 10 Years Roving Across Mars” The museum officials stated that the purpose of the exhibit is to combine art and science in a multimedia experience that visitors will be immersed in. (http://www.space.com/24231-mars-rovers-spirit-opportunity-museum-exhibit.html#sthash.hko79mb5.dpuf)
(Original blog published January 2013)
With all of the hype surrounding the Mars Science Laboratory (MSL) Curiosity, it is easy for the public to forget the Mars Exploration Rovers (MER) Spirit and Opportunity. The twin rovers were each launched by a Delta II Heavy Lifter rocket in the summer of 2003. The Opportunity Rover landed using the airbag method in Meridiani Planum on January 25, 2004 three weeks after the Spirit Rover landed. This month (January 2013) Opportunity is set to celebrate 9 full Earth years on Mars. This very industrious rover was planned for only a 90 day surface mission and has now gone 36 times past its planned mission. The two rovers have made many wonderful discoveries and they paved the way for Curiosity. Each rover had a distinct personality and each have encountered their own challenges. Sadly for the MER team, although Spirit also far exceeded its mission, the last contact with Spirit was in 2010.
Once Opportunity bounced to a stop, she ended up in Eagle Crater. The landing site was named Challenger Memorial Stadium in honor of the astronauts who perished in the Space Shuttle Challenger disaster in 1986. Eagle Crater is a small crater with a layered outcropping of geological features. This was a serendipitous place for a landing, some stating it as an astronomical “hole-in-one”.
In keeping with NASA’s “follow the water” goal on Mars, the JPL website states the following:
“Understanding the history of water on Mars is important to meeting the four science goals of NASA’s long-term Mars Exploration Program:”
- Determine whether Life ever arose on Mars
- Characterize the Climate of Mars
- Characterize the Geology of Mars
- Prepare for Human Exploration”
To accomplish these goals, Opportunity carries a plethora of scientific instruments and cameras. The rover carries a panoramic camera, a hazard camera, and a microscopic imager. It also hosts a suite of spectrometers (an instrument that utilizes the electromagnetic spectrum to analyze data), and a rock abrasion tool (RAT). Many of these instruments are at the end of a robotic arm that extends to sample and analyze the rocks, soils, and minerals.
As the rover traverses the many craters on Mars and stops and analyzes each area, she has made many discoveries. A major discovery at the landing site, as stated by NASA scientists, is that the area was at one time soaked with water. This was determined by the vast number of spherules found at the site that were later determined to be hematite. The spherules were nicknamed “blueberries” due to their shape and distribution. Also, in the false color images they appeared to be a bluish hue. Hematite is found on Earth and is known to be formed in the presence of water over a long period of time. It is a mineral form of iron oxide. This was a major discovery for the MER team. 
An unexpected discovery was Heat Shield Rock. This is a Martian meteorite discovered near the heat shield that had fallen to the ground after the rover landed. This will always be known as the first discovery of a meteorite on another planet. The meteorite was pretty easy to spot against the background of Martian soil and rocks. The “weathering” on a meteorite is quite distinct compared to any indigenous matter.
Ironically the mission has been extended so long, in part due to the weather on Mars. The rover’s power source is in the form of solar panels. The surface of Mars is covered in fine dust and is very windy. Several times over the course of the mission, the solar panels have been covered in dust. The weather on Mars often includes dust devils. These dust devils have been responsible for clearing the dust covered solar panels, thereby, rejuvenating the power to the rover. This was an unexpected and happy event for the team.Opportunity has also made astronomical observations. These include the transits of both natural satellites, Phobos and Deimos, across the face of the Sun. The rover’s cameras have also photographed the Earth, which appears as an indistinct bright object in the Martian sky. This reminds us of how small we really are.
Some of the major craters that Opportunity has visited include, Endurance Crater, Erebus Crater, Victoria Crater, and Endeavour Crater. More recently at Endeavour Crater, Opportunity discovered a bright vein of gypsum. This has been nicknamed “Homestake Vein”. The identification of this substance is more strong evidence of water on Mars in the past. Another recent discovery, in September 2012, at Endeavour Crater is a very dense accumulation of spherules that are different than the hematite spherules previously discovered. It is stated that the spherules in question have a soft middle and crunchy outer layer. They are still being investigated as to what their composition is. As of December
2012, Opportunity Rover has been studying an area at the rim of Endeavour Crater called Matijevic Hill. The mission scientists dubbed this portion of the mission a “walkabout”, referring to the human geologists that explore the perimeter of an area before the interior.