MISC Animation: Using Planets to Visualize the Speed of Light

MISC

Animation: Using Planets to Visualize the Speed of Light

Published

 21 hours ago 

on

 January 28, 2022

By

 James O’Donoghue 

Featured Creator

Article/Editing:

• Govind Bhutada

The Speed of Light Visualized Using Planets

We often come across the term “light-year” in the context of space travel. But what does it actually mean?

A light-year is the distance light travels in one year. At a speed of 186,000 miles/sec (300,000km/sec), light travels 5.88 trillion miles (9.46 trillion km) in a year—a distance well beyond immediate comprehension.

Scientists created the term light-year to measure astronomical distances beyond the confines of the Earth. And in the vastness of space, light photons, which can go around the Earth 7.5 times in just one second, seem slow.

The above animation from planetary scientist Dr.James O’Donoghue helps put the speed of light into a broader perspective while highlighting the vast distances between celestial bodies.

Light Speed: Fast, but Slow

The Moon is the nearest celestial body to Earth at 239,000 miles (384,400 km) away. A light photon emitted from Earth would get to the Moon in a mere 1.25 seconds.

But how does this compare to other celestial bodies in our solar system?

Celestial BodyDistance at Closest ApproachLight Travel Time from Earth

Moon	0.38 million km	1.25 sec
Mars	54.6 million km	3 min
Sun	150 million km	8 min
Jupiter	588 million km	33 min
Saturn	1.2 billion km	67 min
Pluto	4.3 billion km	4 hrs

If you watched the entire length of the above video, you probably saw how “slow” light is. The same photon of light that reached the Moon in a little over a second took three long minutes to reach Mars, the next planet beyond Earth in our solar system.

It takes light just over eight minutes to get from the Sun to Earth. This means that when we look at the Sun, we see it as it was eight minutes ago, and if it were to disappear suddenly, we wouldn’t realize it for eight whole minutes.

Therefore, how “fast” or “slow” light is depends on your perspective. To us Earth-dwelling humans, it feels instantaneous. But the vastness of the universe makes even light seem slow—and it travels at a speed that our spacecraft aren’t even close to matching.

This article was published as a part of Visual Capitalist's Creator Program, which features data-driven visuals from some of our favorite Creators around the world.

Animation: Using Planets to Visualize the Speed of Light (visualcapitalist.com)

Animation: Using Planets to Visualize the Speed of Light