sinse the late fifties, thousands of artificial satelliters have been put in the earth is orbit. many are now out of action, just scrap metal in space. some satellites provide reliable information for weather forecasting. others can measure movement in the earth is crust which may indicate earthquake activity in the near future. there are satellites which can indicate the exact location of forest fires long before they could be spotted by observation on the earh. some satellites have sensitive photographic equipment which can show how well crops are growing in the fields and make measurement of rivers and desert. in the future, satellites. in the form of giant mirrors, could provide illumination for cities and roads by reflecting the sun is rays onto earth is nigh side.