Perhaps the hardest thing to wrap one's mind around in astronomy (or in anything, for that matter) is scale: just how big these objects are, how far away they lie, and how long ago they formed. How can anyone understand a planet that is more than 1,300 times the size of our own? Or the 93 million miles between us and the sun? And these are just measurements in our own solar system, a puny speck in the galaxy, to say nothing of the entire universe. Our intuitive sense of sizes, distances, and time are of little help when it comes to space.
Space artist Ron Miller has created a series of images that illustrate the sizes of the other planets in our solar system in a way that makes them a bit more accessible, showing what they would look like if they were 240,000 miles away -- the approximate distance of the moon from the Earth. He began with a picture of the moon over Death Valley (up top), and then calculated the number of degrees in the sky a given planet would take up at that distance. "For instance," he explained to me over email, "the moon covers just 1/2 a degree. Venus would cover about two degrees, so it would appear about four time larger than the moon."
The other thing Miller decides is how wide to make the entire picture. "I usually choose 50 or 60 degrees, which emulates a typical snapshot," he explains. "This determines how much space the planet takes up in the final picture."
Miller says he's always loved astronomy. "It helped to grow up in the Sputnik and Mercury program days, when you couldn't open your eyes without seeing something about rockets," he writes. But an "utter ineptitude with math" led him to pursue his interest via a different path: art. For five years he was the art director at the National Air & Space Museum.
Miller likens the work of being a space artist to the crafts of forensic and paleontological arts, both of which require their practitioners to rely on small bits of information -- bones, fossils, other clues -- to imagine what something once looked like. Or, in this case, what it would look like, were the solar system radically different, and Jupiter were our very close neighbor.
"Of course," he continues, "the role of being an inspiration is important, too. Space artists have in fact been an important factor in the history of the development of space flight and have additionally inspired hundreds of people to pursue careers in astronomy or astronautics." He points to a painting by Chesley Bonestell from 1944 of Saturn as it would appear from its moon, Titan, once described as "the painting that launched a thousand careers." Here's how it would appear here from Earth, if it were at the distance of our moon:
No offense to our moon, but imagine looking up in the sky and seeing this:
Miller thinks that the night sky shapes who we are, and having a huge other planet so large would change us. "'We would all feel a lot more humble with Jupiter's presence constantly looking over us," he told The Daily Mail.