In 2009, NASA's Messenger spacecraft became the second spacecraft to orbit the planet Mercury. The spacecraft orbited at a height of 125 miles above Mercury's surface. You can assume this is a circular orbit. Determine the orbital speed and orbital period of Messenger. (GIVEN: RMercury= 2.44 x 106m; MMercury= 3.30 x 1023kg; 1 mi = 1609 m)