AD Quality Auto 360p 720p 1080p Top articles1/5READ MOREWhicker: Clemson demonstrates that it’s tough to knock out the champSpirit’s solar panels, shrouded by a layer of fine dust from July’s planetwide dust storms, are collecting less than half the sunlight hitting them. By the depths of winter, that number is expected to drop even further, Callas said. There is little hope of reprieve. On Mars, winter is not a windy season, so the dust layer will likely coat Spirit for many months to come. Without enough power from sunlight, Spirit’s heaters – its only line of defense against temperatures as low as 130 degrees below zero Fahrenheit – cannot run. PASADENA – It is fall in Mars’ southern hemisphere. With every new day, the sun arcs lower across the horizon and the cold and dark creep farther north over the red Martian soil. Although some of Mars’ robotic explorers are unaffected by the changing seasons, the coming winter could spell the end of the rover Spirit’s slow sojourn across the Red Planet’s surface. “This will be the toughest winter for Spirit. This will be the greatest challenge since she landed (in early 2004),” said John Callas, project manager for the rovers at JPL in Pasadena. JPL engineers are now driving the rover to the edge of the feature known as Home Plate, where they can park it for the next several months with its solar panels turned as far toward the sun as possible. They have already conceded, however, that they will have to turn off the heater protecting one instrument used to study minerals, and will possibly have to turn down another heater, allowing Spirit’s electronics to drop to minus 67 degrees Fahrenheit (minus 55 degrees Celsius). “The rover’s electronics were tested to minus 55 degrees Celsius,” Callas said, but “the minus-55 testing was done with a brand-new rover. These rovers are now four years old. There is a risk that if we allow the rover to get colder, things could break.” Spirit will have to survive until the winter begins to lift in July before engineers can be confident it will live to see another spring. But elsewhere around Mars, the news isn’t so grim. “Opportunity is doing great,” Callas said. “Power is not an issue for Opportunity because she’s closer to the equator and doesn’t have nearly as much dust on her arrays,” he said. Unlike Spirit, Opportunity will not have to hibernate to conserve energy but will instead continue its investigations of Victoria Crater. Already, it has visited two of three layers in the intriguing bright band of rock circling the crater’s inside like a bathtub ring. “We could finish up our activities there and be out within a couple months,” Callas said. And, from high above the Martian surface, the Mars Reconnaissance Orbiter (MRO) continues to dazzle scientists with the high-resolution images it captures of the planet below. For eight months this year, it watched as spring crept over the south pole, transforming the creased and rutted terrain known as the Cryptic region. With MRO’s observations, JPL planetary scientist Candice Hansen said, scientists were able to show that the scarred landscape was caused as sun pierced the translucent ice caps, made not of water but of dry ice – frozen carbon dioxide. With the sun warming the soil below, the bottom of the ice layer turned to gas, building up pressure beneath its frosty cap. When the gas finally forced its way through the ice, it carved channels into the ground as it rushed outward and jetted fans of dust and dry ice onto the surface. “The interesting thing is that we have nothing like this on Earth – nothing,” Hansen said. The shapes etched into the ground, called araneiform or “spiderlike,” come in many varieties. “There are spiders that link up to each other. There’s spiders that don’t link up to each other. There’s circular spiders, there’s elongated spiders. There’s shallow ones, there’s deep ones,” she said. From above, it makes the martian surface look like lizard skin, or like lace. With spring now coming to Mars’ north pole, MRO’s powerful cameras will soon study whether the same features exist there, as well. There are big plans for Spirit, too. Earlier this year, the intrepid explorer unearthed soil so rich in silica “it’s really strong evidence that this area we were traversing over was either the source of a hot spring or the source of some volcanic fumarole,” said Bruce Banerdt, JPL’s rover project scientist. The find was particularly interesting because “these areas on Earth are places where we find very vigorous biological activity,” he said. Since then, the rover’s panoramic camera has spotted other areas to the south similar in appearance to the area now nicknamed “Silica Valley.” “We’re hoping to go south and investigate some of these areas where we see some of these knobby outcrops,” Banerdt said. But first, Spirit’s biggest challenge will be just to survive the Martian winter. [email protected] (626) 578-6300, Ext. 4451160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set!