among the eight planets in the solar system. mercury is the smallest and closest to the sun with an orbital period of about 88 earth days.seen from the earth. it appears to move around its orbit i about 11days. which is much faster than any other planet. this rapid motion may have led to it being named after the roman deity mercury. the fast flying messenger to the gods.mercury revolves around the sun at a speed of about 48.8692 km per second.round this number to the nearest hundredths and thousandths.​