SOLAR SYSTEM

Detailed explanation-1: -Kepler’s Second Law Describes the Way an Object’s Speed Varies along Its Orbit. A planet’s orbital speed changes, depending on how far it is from the Sun. The closer a planet is to the Sun, the stronger the Sun’s gravitational pull on it, and the faster the planet moves.

Detailed explanation-2: -The point of nearest approach of the planet to the Sun is termed perihelion. The point of greatest separation is aphelion, hence by Kepler’s Second Law, a planet is moving fastest when it is at perihelion and slowest at aphelion.

Detailed explanation-3: -Therefore the planet moves faster when it is nearer the Sun and slower when it is farther from the Sun. A planet moves with constantly changing speed as it moves about its orbit. The fastest a planet moves is at perihelion (closest) and the slowest is at aphelion (farthest).

Detailed explanation-4: -The closer a planet is to the Sun, the less time it takes for it to go around the Sun. It takes less time because the length of the orbit is shorter (a smaller orbit), but it also moves faster in its orbit. Thanks to gravity, it has to move faster in its orbit to stay in orbit!

Detailed explanation-5: -Answer: Mercury is the winner at an orbital speed of about 47.87 km/s (107, 082 miles per hour), which is a period of about 87.97 Earth days.

Detailed explanation-6: -The exact speed changes, because at perihelion, we’re closer to the Sun and feel its gravity a bit more strongly, so our speed around the Sun is a bit faster than at aphelion.