We all know the sun is big. But this image, part of a great series on the size of astronomical objects by John Brady, underscores that it’s vast on a scale that’s simply impossible for our puny human minds to understand. We think of the Earth as a big place: flying around the equator on a 747 at top speed would take about 42 hours. Flying around the sun at the same speed, by contrast, would take about six months.
Compared with the overall vastness of space, the moon is very close to us: it’s just 238,900 or so miles away. But compared with our daily experience, absolutely everything in space is absurdly far apart. In the gap between us and the moon, you could neatly slide in all seven of the other planets — with a bit of room to spare. That includes Saturn and Jupiter, which are about nine and 11 times as wide as Earth, respectively.
3) From Mars, Earth would look like a tiny blip in the sky
If you traveled just a little ways away from Earth — say, to Mars, the second-closest planet to us — our home planet would become a tiny blip in the sky. This photo, by NASA’s Curiosity rover, was actually taken when the two planets were relatively close together: about 99 million miles away (at other times in the planets’ orbits, they can be five times farther apart).
Jupiter is famous for being big. But this image, another one of John Brady’s great astronomical size comparisons, will overwhelm you with just how big. Jupiter’s Great Red Spot — a cyclone that was first spotted in 1655 — is shrinking, but it’s still many times wider than North America. Jupiter and the other gas giants are so big because their colder temperatures allowed them to hold on to lighter gases such as hydrogen and helium, which floated away from the hotter, rockier planets closer to the sun.
Another way to understand how big the gas giants are is to picture what they’d look like to us if they replaced the moon. Illustrator Ron Miller did this with a photo of a full moon over Death Valley, replacing it with each planet in turn. In this location, Saturn would blot out a large swath of the sky, and solar eclipses would last hours. (Of course, the gravitational consequences of having Saturn that close to us would also be devastating.)
This is the comet 67P/C-G — which the Philae probe landed on in November 2014 — superimposed on Los Angeles. In terms of space, the comet is absolutely tiny: just 3.5 miles wide. But once again, this image shows how most things in space are way bigger than you realize.
7) All of US history has occurred within a single Pluto orbit
It’s not just the size of objects in space that boggles the mind — it’s the vastness of the timescales on which events in space occur. Pluto takes 248 Earth years to orbit the sun. To put it another way, the entirety of US history has occurred during a single Plutonian orbit. When Pluto was last in its current location, we hadn’t invented aviation, let alone spaceflight. This map was released by NASA’s New Horizons team in anticipation of the probe becoming the first spacecraft to visit Pluto in July.
8) Pluto isn’t even at the edge of the solar system
Many of us imagine cold, little Pluto to be at the outer edge of the solar system. But that’s far from the truth. Pluto’s orbit fits inside the tiny blue box at the center of this map. Beyond it is the Kuiper belt, then the Oort Cloud — which is believed to extend a thousand times farther out than Neptune, about halfway to the next closest star to us.
Once you leave the solar system, you once encounter objects — other stars — that dwarf our sun in the exact same way the sun dwarfs Earth. And even bigger stars (like Antares and Betelgeuse, in pane 5) dwarf those stars in the same way. Over and over, as we’ve looked out at the universe, we’ve found it exists on a scale that basically makes no sense to the human brain.
10) Every star you can see is in the yellow circle
Sure, stars are huge. But the Milky Way is, once again, mind-bogglingly bigger. This rendering, which shows the galaxy in its entirety, is a way of seeing that. The yellow circle likely encompasses every individual star you’ve ever seen in the sky without the aid of a telescope. It’s based on the fact that under ideal conditions, people in the Southern Hemisphere can see the especially bright star system Eta Carinae — but in most places, the yellow circle would actually be much smaller.
For all its vastness, the Milky Way is just one of billions of galaxies in the universe. Recently, scientists mapped the 100,000 or so galaxies near the Milky Way and found that it’s part of a broader supercluster called Laniakea. This supercluster is made up of several forks, with the Milky Way lying on one distant fringe of it. What’s more, it borders another supercluster (called Perseus-Pisces) that’s moving in the opposite direction, and both seem to fall in a broader web, made up of dense supercluster networks alternating with relatively empty voids.