A spacecraft orbiting Mars has scanned huge deposits of water ice at its south pole so plentiful they would blanket the planet in 36 feet of water if they were liquid, scientists said on Thursday. The scientists used a joint NASA-Italian Space Agency radar instrument on the European Space Agency Mars Express spacecraft to gauge the thickness and volume of ice deposits at the Martian south pole covering an area larger than Texas. The deposits, up to 2.3 miles thick, are under a polar cap of white frozen carbon dioxide and water, and appear to be composed of at least...