Which statement is TRUE regarding how planets travel in space?
A). Planets speed up as they travel away from the sun.
B). Planets stay the same distance away from the sun at all times.
C). They slow down as they approach the sun.
D). The distance between planets and the sun varies.
D). The distance between planets and the sun varies.
D). The distance between planets and the sun varies.
To determine the correct statement regarding how planets travel in space, we need to consider the basic principles of planetary motion.
The most accurate statement among the given options is D). The distance between planets and the sun varies.
This principle is known as Kepler's law of planetary motion. According to this law, planets move in elliptical orbits around the sun, with the sun located at one of the foci of the ellipse. As a result, the distance between a planet and the sun changes as the planet orbits.
During a planet's orbit, it will experience different speeds at different points in its journey. Kepler's second law, known as the law of equal areas, states that a planet sweeps equal areas in equal times. This means that a planet moves faster when it is closer to the sun (perihelion) and slower when it is farther away (aphelion).
So, while option A states that planets speed up as they travel away from the sun, this is incorrect. The correct statement is D), where the distance between planets and the sun varies based on their elliptical orbits.