How Big? How Far? - A Scale Model of the Universe

The true size of the universe boggles the mind. It’s so large that it is simply impossible to truly grasp its size. Even light, which travels faster than anything else, takes time to travel through space. For light, it’s eight minutes from the Sun to Earth, four years to the closest star, and a hundred thousand years to cross the Milky Way. To truly appreciate these vast distances, a scale model is necessary.

100 Earth could be lined up end-to-end across the diameter of the Sun.

Let’s make the Sun the basis of the scale model and shrink it down to the size of a basketball. If the Sun were the size of a basketball, then the Earth would be a tiny bead, less than a tenth of an inch across. You could line up 100 Earths across the diameter of the Sun. Even our solar system’s largest planet, Jupiter, would only be a marble about an inch in diameter. As for distance, the Sun is 93 million miles from Earth. To scale, the bead-sized Earth would be 83 feet away from the basketball Sun. This is about a quarter the length of a football field. Meanwhile, Neptune, the furthest planet from the Sun, would be over half a mile away, or over 8 football fields.

Moving beyond our solar system, the closest star to the Sun is Proxima Centauri. It’s 4.3 light-years away, meaning it takes 4.3 years for light to travel from one to the other. That translates to over 25 trillion miles. Even on our scale model, Proxima Centauri would be 4,374 miles away from the basketball Sun. That’s about the distance across the Pacific Ocean from California to Japan. Even if the basketball were placed in the center of the Earth, the closest star would still be 400 miles above the Earth’s surface.

VY Canis Majoris is one of the largest stars we’ve discovered. Its radius is 1,400 times that of the Sun. You could cram nearly 3 billion Suns into VY Canis Majoris. If the Sun were a basketball, then VY Canis Majoris would be about 1,100 feet in diameter. That’s wider than the Eiffel Tower is tall. VY Canis Majoris is also about 3,900 light-years away, meaning on the Eiffel Tower-sized star would be nearly 4 million miles away from the basketball Sun. That’s 16 times further than the actual distance between the Earth and Moon.

In this image, the largest object in each section is the smallest object in the next section. Even the Sun would not visible in the final section when compared to VY Canis Majoris. Image Credit: Dave Jarvis (CC BY-SA 3.0)

But things get even crazier. The Andromeda Galaxy is the closest galaxy to the Milky Way at about 2.5 million light-years. On the basketball scale, that’s 2.5 billion miles away. The basketball scale model is officially meaningless, as 2.5 billion miles is nearly 27 times the actual distance between the Earth and Sun. You’d need a scale model to explain our scale model. As for size, the Andromeda Galaxy, which is about double the diameter of our own Milky Way, would be over 200 million miles across. So even the scaled-down galaxy would be over twice the size of the actual distance between the Earth and Sun.

So, let’s scale everything down again. Let’s now make Andromeda the size of a basketball instead. On this scale, Earth would be far smaller than even an atom. The largest galaxy known is designated ESO 383-76. It’s 1.8 million light-years across, which is 8 times the size of Andromeda. If Andromeda were a basketball, it would be the width of an SUV. For distance, it’s about a 654 million light-years from Earth, making it about half a mile away from the subatomic Earth in the new scale.

But what’s the farthest we can do? The most distant galaxy ever seen is currently known as MoM-z14 and was discovered in May of 2025 by the James Webb Space Telescope. Light from it had to travel 13.53 billion light-years to reach Earth, with the light we see from it now having left it a mere 280 million years after the Big Bang. That puts it just over a scaled 9 miles away from Earth, which is nearly twice the height of Mt. Everest. Just for fun, if we were to use our original scale model with the Sun as a basketball, the galaxy would be 13.8 trillion miles away. That’s over 2 light-years away on a scale model! If the Sun were a basketball, then the furthest known galaxy would be halfway to the closest star without a scale!

Everything you know and likely ever will know exists on the Earth, which is smaller than the most insignificant speck of dust when compared to the size of our universe. There is so much out there beyond our planet that it can never truly be known. But that doesn’t mean it’s not worth studying. It’s the opposite. There will always be new discoveries to make, so we have to strive to keep on making them, or risk having them go unknown forevermore.