Why Do Inner Planets Take Less Time to Orbit the Sun?

What Crafty Clover says in this video

Intro

Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why do inner planets take less time to orbit the Sun?

The Big Idea

Inner planets take less time to orbit the Sun because they have shorter paths and move faster! The Sun's gravity is stronger close to it. Mercury zips around in only 88 Earth days, while Neptune needs about 165 Earth years. Nearer means a quicker year!

A Shorter Path

Step one: a shorter path. A small circle close to the Sun is much shorter to travel than a huge circle far away. So inner planets have less distance to cover, and finish their laps sooner.

Faster Speed

Step two: faster speed. Close to the Sun, gravity is stronger, so planets must move faster to stay in orbit. Mercury races along at about 47 kilometres every second.

Kepler's Rule

Step three: Kepler's rule. Johannes Kepler, a German astronomer, figured out this pattern about 400 years ago. The farther away a planet is, the slower it moves and the longer its year.

A Closer Look

Let's compare some planet years! Mercury circles the Sun in 88 days. Earth takes 365 days. Mars takes 687 Earth days, almost two years. And Neptune needs about 165 Earth years!

Quick Facts

Quick facts! Neptune was found in 1846, and finished its first full orbit since then in 2011. Jupiter's year is nearly 12 Earth years. Saturn's year is about 29 Earth years. Remember the order: Mercury, Venus, Earth, Mars, and then the giants, each with a longer year.

Think Like a Scientist

Now, think like a scientist! Rank the planets by year length from memory. Shortest year first, longest year last. Then look up the real answer. How many did you get right?

Outro

Planets near the Sun have speedy years. Science is amazing! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!