switching off a malfuctioning memory system.
Even so, it may be three weeks or more before Spirit can resume scientific investigations, and the memory problem may prevent it from recovering full operational capacity.
Mission control had said that it could take 22 hours for Opportunity to make contact with Earth following its scheduled arrival at 5.05 am, but the rover sent signals within moments of landing. Scientists cheered, and were congratulated by Arnold Schwarzenegger, the Governor of California, and former Vice President Al Gore, who joined the vigil at the laboratory.
Sean O’Keefe, the NASA administrator, saluted his team for landing both rovers successfully, and for beating the “Mars jinx under which two thirds of all missions to the planet have failed. What a night,” he said as he broke open champagne for a second time in three weeks. “No one dared hope that both rover landings would be so successful.”
While Spirit landed on the base petal of its protective pyramidal shell, Opportunity landed on a side petal and had to be flipped into an upright position.
All the airbags that cushioned it on landing appear to have been successfully retracted. One of Spirit’s airbags refused to deflate properly forcing engineers to turn the rover 120 degrees before it could be driven away from the landing module.
British scientists will today begin one of their final attempts to find their missing Beagle 2 lander. The team has not tried to contact the probe for almost two weeks to try to force it into an emergency transmission mode.
NASA’s Opportunity Mars rover has landed in a small crater, to the delight of scientists who hope that it will provide a ready made window into the planet’s geological past.
The shallow crater, about 65ft across, was formed by a meteor impact, which has performed natural excavation work allowing the rover to peer below the Martian surface without having to dig.
Steve Squyres of Cornell University, lead scientist for the Mars rovers, said that the crater was ideal: big enough to be of great scientific interest but not so deep that the six wheeled robot would be stranded. “We have scored a 300 million mile interplanetary hole in one,” he said. The rover will spend at least a week unfolding itself before leaving its landing module.
British scientists have begun a post-mortem examination into the failure of Beagle 2. Colin Pillinger, the mission’s chief scientist, said yesterday that his team accepted the probable loss.
Direct evidence that Mars was once awash with liquid water has been discovered for the first time, proving that life could once have existed on the planet and may still be there.
NASA scientists announced last night that the Opportunity rover had determined that the rocks of its Meridiani Planum landing site had been soaked in liquid water, the prerequisite of life on Earth.
The startling findings show unequivocally that at least part of the Red Planet has been wet and habitable in the past, with conditions suitable for living organisms to evolve and survive.
Steve Squyres, chief scientist for NASA’s rover mission, said that while the discovery does not prove that life had ever existed on Mars, it shows beyond doubt that it is a real possibility.
“The purpose of going to Mars was to see whether or not it was a habitable environment,” he said. “We believe that this place, in Meridiani Planum, at some point in time was habitable. That doesn’t mean life was there, but it is a place that was habitable at one time.”
James Garvin, NASA’s lead scientist for Mars exploration, said, “NASA launched the Mars Exploration Rover mission specifically to check whether at least one part of Mars ever had a persistently wet environment that could possibly have been hospitable to life. Today we have strong evidence for an exciting answer – ‘yes’.”
Observations from orbit, most recently from the European Mars Express spacecraft, have shown that frozen water exists at the Red Planet’s poles. Probes have also photographed geological features such as canyons and dried-up beds that appear to have been carved by rivers, oceans and lakes.
Water, however, must exist in its liquid form to sustain life, and no direct evidence of this had been found before Opportunity’s investigations.
The conclusion that the rocks of Meridiani Planum, where Opportunity landed on January 25, were once underwater follows three weeks of meticulous experiments. “We’ve been attacking it with every piece of our hardware and the puzzle pieces have been falling into place,” Dr Squyres said.
Four separate pieces of evidence have combined to build a compelling picture. The alpha particle X-ray spectrometer has found high concentrations of sulphate salts, which have to be dissolved in water to accumulate. The Mossbauer spectrometer has also found a mineral called jarosite, which is formed in the presence of water.
Physical features of the rock have provided important clues. Round particles known as “spherules”, which Dr Squyres likened to “blueberries in a muffin”, appear to have been formed by dissolved minerals. Holes known as “vugs” have been left by crystals of salt, laid down in briny water.
Some of the key discoveries came from analysis of a rock nicknamed El Capitan, after a rock formation in Yosemite National Park in California.
“Put the story together, and it is hard to avoid the conclusion that this stuff was deposited in liquid water,” Dr Squyres said.
Ed Weiler, NASA’s associate administrator for space science, said, “Opportunity has landed in an area of Mars where liquid water once drenched the surface. This area would have been a good, habitable environment.”
Scientists will have to wait, however, to find out whether this environment actually supported life. Neither Opportunity nor her sister rover, Spirit, carries the instruments needed to search for traces of living organisms. Britain’s Beagle 2 Mars probe, which was lost last year, did carry two experiments that would have been able to detect life.
The question of whether water and life ever existed on Mars dates from the 17th century, when the Dutch astronomer Christiaan Huygens first identified light patches at the poles that appeared to be ice caps.
The notion, however, did not capture the public imagination until the 1890s, with the publication of three books by the American Percival Lowell.
Inspired by the work of the Italian astronomer Giovanni Schiaparelli, who in 1877 had seen a criss-cross network of straight channels, or canali, on the Martian surface, Lowell built an observatory in Flagstaff, Arizona, from which to examine the planet more closely.
Having mistranslated canali as “canals”, Lowell concluded that the lines were evidence of a vast irrigation system built by an intelligent civilization. By 1910, his theory was complete: Mars was drying out and dying through lack of water, accounting for its red hue and necessitating the irrigations.
The hypothesis eventually foundered on the discovery that Schiaparelli’s canali did not exist: they were optical illusions produced by the telescopes of the period. But the idea that Mars could be wet and inhabited stuck, inspiring hundreds of science fiction novels and films.
In the 1960s and 1970s, a series of Martian flypasts by NASA’s Mariner Spacecraft dispelled any possibility that Mars was at all Earth-like, showing that carbon dioxide, rather than water and oxygen, was the main component of its atmosphere and ice caps. The Viking landings of 1976went further, finding no conclusive evidence of either water or life, although some investigators still contend that the results of one of the spacecraft’s experiments turned up positive for the existence of micro-organisms.
The result was a 20-year hiatus in Mars exploration as space scientists, largely convinced that the planet was barren, turned their attention and dollars elsewhere.
All that changed, however, on August 6, 1996, with the discovery of the Martian meteorite ALH84001, which contained mineral deposits that some scientists interpreted as fossilised microbes.
Interest in Mars was revived overnight.
