Half a dozen possible landing sites have been selected for NASA鈥檚 Mars Science Laboratory (MSL), due to launch late in 2009. The rover, the largest ever to travel to Mars, will try to find out whether the Red Planet was once conducive to life.
The rover should touch down on Mars in October 2010. It will study the make-up of organic compounds, and how Martian rocks and soil have evolved over time. It will also explore the role of water in the planet鈥檚 history and measure the radiation hazard from the Sun and energetic charged particles from the galaxy called cosmic rays.
Advertisement
鈥淚n a nutshell, MSL is going after the question of habitability on Mars,鈥� says John Grant, a geologist at the National Air and Space Museum in Washington, DC, US.
快猫短视频s have considered more than 50 possible landing sites for the rover. At a workshop last week in Pasadena, California, US, they narrowed them down to six. All six sites appear to have clay minerals, which scientists think must have formed in prolonged contact with liquid water (watch a .)
The six favoured sites are:
声 (24潞 north): an ancient water outflow channel with light-coloured clay-rich rocks
声 (22潞 north): a fracture that has been eroded and partly filled in by sediments and clay-rich ejecta from a nearby crater
声 Jezero Crater (18潞 north): an ancient, once-flooded crater containing a fan-delta deposit rich in clays
声 Southwest Meridiani (3潞 south): a site where there is evidence for an ancient and widespread clay-rich layer near the surface, as well as slightly younger materials containing sulphates, which also require water to form
声 (26潞 south): an ancient lakebed with layered clay-rich sediments
声 (28潞 south): another ancient lakebed with diverse deposits including clays
Grant says he personally favours Holden Crater. But both Holden and Terby craters, which lie in the southern hemisphere, could turn out to be unsuitable because the rover would arrive during the local winter. As a result, it might have to hibernate during the coldest spells because it couldn鈥檛 function properly.
It鈥檚 not clear yet how big a problem this would be. 鈥淚f operations were reduced by 50 per cent, for instance, that would be a real hit,鈥� says Grant, who is joint chair of the landing site selection committee. 鈥淏ut those things are being worked on very hard as we speak and we鈥檒l have a much better sense in the coming couple of months.鈥�
鈥楶urgatory鈥� site
快猫短视频s will spend the next nine months studying images from NASA鈥檚 Mars Reconnaissance Orbiter to find out more about the six sites. Engineers will also examine which sites are safest to land on. The ideal site would be flat and not prone to high winds.
鈥淭he spacecraft can鈥檛 land effectively on a very steep incline,鈥� Grant told 快猫短视频. 鈥淭he numbers and sizes of rocks on the surface are also issues 鈥� you don鈥檛 want the rover to land on a very large rock sticking up a metre above the surface.鈥�
In case all the six prime sites turn out to be unsuitable, the teams will also study four other 鈥減urgatory鈥� sites. Grant expects that another workshop in six to nine months will narrow the landing site down to a certain latitude range, then a single site will be selected by October 2008, a year before launch.
Mars Rovers 鈥� Mars is full of surprises; learn more in our continually updated .
