Putting things in perspective

The following is excerpted from “40 maps that explain outer space” by Joseph Stromberg.

What it’d look like if other planets replaced the moon


“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, using a photo of a full moon over Death Valley but replacing it with each planet in turn. In this location, Uranus and Neptune would be alarmingly big, but Saturn and Jupiter would be so huge that they’d blot out a large swath of the sky. Solar eclipses, Miller points out, would last hours. (Of course, the gravitational consequences of having Jupiter that close to us would also be devastating.)”

What North America looks like compared with Jupiter


“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 onto lighter gases such as hydrogen and helium, which floated away from the hotter, rockier planets closer to the Sun.”

The moon is surprisingly far away from Earth.


“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 really, really 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 9 and 11 times as wide as Earth, respectively.”

The sun is absolutely ginormous.


“It might not be a big surprise to you that the sun is really, really 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 difficult 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.”

Other stars are utterly gigantic.


“We’ve already looked at a number of incomprehensibly huge astronomical objects in these maps. But other stars (like Arcturus and Aldebaran, in pane 4) dwarf our sun in the exact same way that 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.”

We are light years from any other star.

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[Click the image above to watch the video.]

“Because we can see so many stars at night, it’s tempting to imagine that our solar system sits right next to other ones, like houses on a street. But the truth — as shown by this GIF made from the 100,000 Stars explorer — is that our solar system, like most others, is a lonely one, like a single house in an entire city. You have to zoom way, way out (several light years) to see just a handful of other stars. By analogy, if you put Earth at home plate and the sun on the pitcher’s mound, the next-closest star would be 800 miles away.”

The Milky Way galaxy is incomprehensibly huge.


“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 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. In either case, it’s clear that the vast majority of our home galaxy — which contains at least 100 billion stars like ours — is simply beyond the realm of what our eyes can observe.”

There are untold billions of galaxies.


“If we look hard enough, we can actually see these distant galaxies ourselves. This image, taken by the Hubble space telescope, shows an ultra-zoomed-in view of a tiny slice of the sky, a fraction of the size of the moon. Looking this deeply into the sky revealed more than 10,000 galaxies, and because of the time it takes for their light to reach us, this photo shows some of these galaxies as they were more than 13 billion years ago — shortly after the formation of the universe.”



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