How far away is the Moon?
Usually, when you see pictures of the Earth and the Moon in space, they’re about this close together.
This looks pretty, but it’s completely wrong.
The Moon is actually this far from the Earth. It’s 238,900 miles away, or 384,400 kilometers if you prefer larger numbers.
If you’re using a desktop web browser, click this button to view the image fullscreen. Stare at it for a minute and try to wrap your head around the scale of what you’re looking at.
How long would it take to travel to the Moon?
At highway driving speed, it would take you about 150 days to reach the Moon, but this is obviously impossible because it’s unlikely you could stay awake that long and also you’d have to stop to eat and use the restroom.
The Apollo astronauts only took 3 days to get to the Moon, but the tickets were prohibitively expensive.
The Moon wasn’t always this far away
Using lasers and mirrors left behind by the astronauts, we’ve been able to measure the distance from the Earth to the Moon with great precision. Surprisingly, it was discovered that this distance is increasing at the rate of a few centimeters each year.
Working backward from these measurements, we can tell that when the Moon formed 4.5 billion years ago, it was seventeen times closer to the Earth.
At the time, it looked more like this, which coincidentally is how it appears today in movies and TV shows. 👀
This was clearly a bad idea, which presumably is why we had the Moon moved to a safer distance.
The stars are also wrong
While I have your attention, I have to point out something else that bothers me about a lot of fictional space imagery.
Often, in a movie you’ll see space scenes with visible stars like this one.
It’s also completely wrong.
The Earth should actually look like this. This is a real picture of the Earth, taken by Apollo 16 on its way to the Moon.
Why aren’t the stars visible?
When you’re looking at a picture of the Earth in space, it’s important to realize that the Earth you’re looking at is just as bright as what it looks like outside your house in the daytime. After all, you’re looking at the sky from the other side.
Keeping that in mind, think about what you see outside at night, and how bright the stars in the sky are. Compared to daylight, stars are extremely dim because they’re so far away.
You can see the stars at night because your eyes adapt to the darkness, but the stars are about a million times dimmer than daylight.
The upshot is, when you’re looking at picture of the Earth in space, the stars in the image are a million times darker than the Earth. They would be indistinguishable from the blackness of space.
omg hi thanks
Thanks for reading. While you’re here, please check out the app I made that helps you visualize four dimensions in your head. It’s true, you really can do this.
The Fourth Dimension
Learn how to visualize four-dimensional space by playing with a tesseract
Find out more