how fast do the planets orbit the sun
Mercury circles the Sun in only 88 days, compared to 365 days for Earth, at at an average speed of 105,947 miles (170,505 kilometers) per hour. This is faster than any other planet in the Solar System.1  Javascript must be enabled to use Cool Cosmos. 2  Learn how.ercury circles the Sun in only 88 days, compared to 365 days for Earth, at at an average speed of 105,947 miles (170,505 kilometers) per hour. This is faster than any other planet in the Solar System. 1  Javascript must be enabled to use Cool Cosmos. 2  Learn how.