space is just cool

Space is awesome. There’s no arguing that. But all of the really cool stuff is way out there—beyond the edges our solar system—in deep space. In fact, our solar system is pretty lousy. Everyone learns about it in first grade: You’ve got nine planets (or eight since Pluto got the boot), a few boring moons flying around them, the Sun, and that’s pretty much it—right? Actually, space has more wonders than you could possibly imagine, and some of them are right in our backyard.

The Asteroid With Its Own Moon

Logic would dictate that anything smaller than a planet doesn’t have the gravitational pull to hold onto a moon, but thats not always the case. Enter243 Ida, an asteroid that’s only 30 kilometers (19 mi) across when you measure it the longest possible way. Ida has a tiny, 1.6-kilometer (1 mi) moon orbiting it (Dactyl). It’s the first binary system of asteroids that we found and the only one we’ve done a close enough flyby of to get clear pictures, but we’ve since discovered over a dozen binary asteroids.

Pluto Isn’t Anything Like We Thought

Despite how long we’ve known Pluto existed, we know surprisingly littleabout the dwarf planet. For example, that photo up there? That’s the clearest image of Pluto we have, and even that is cobbled together from several shots.

This is because space is big—staggeringly, stupid, crazy big. At its absolute closest, Pluto is 4.2 billion kilometers (2.6 billion miles) away, which is a number so big that our brains don’t really know what it means. The most powerful telescopes we have only give us a grainy, out-of-focus image at that enormous of a distance.

But these images are sharp enough to tell us that Pluto is nothing like we first imagined: a boring hunk of rock. It’s surface is a carbon-rich mixture of white, black, and dark orange, and we’ve observed the poles lightening and darkening over time. Our best guess at present is that these are seasonal changes, spurred on by the distant sun that sublimates surface methane and flings it into the atmosphere (yeah, it has one of those, too).

Saturn’s Enormous Ring

The one thing everyone thinks of when Saturn is mentioned is its vast array of rings. And while it’s certainly not the only planet with a ring system, they’re definitely the most spectacular example. What we didn’t know until recently is that Saturn’s ring system extends much farther than we first thought.

The ring, made of dust and ice, has eluded discovery for so long because it’s almost invisible, and if you don’t look at it in infrared, it’s easy to miss. Thesheer size of the ring is hard to visualize—it begins 6 million kilometers (3.7 million miles) from Saturn and extends all the way out to 12 billion kilometers (7.5 billion miles). It’s 20 times as thick as the planet’s height, and Saturn isn’t small. You’d have to use one billion Earths to fill the space the ring takes up.

Space

There are so many awesome things in our solar system that we often forget how empty it really is. They call it “space” for a reason. That’s what it mostly is: empty space. (That’s an image of the Earth and the Moon up there—just look at all that room.)

The Sun itself is 99.8 percent of all the mass in the solar system. Logically, that means that everything else—the enormous gas giants; every asteroid, comet, and meteoroid; and smaller planets like Earth—comprise only 0.2 percent of the matter, most of which is Jupiter.

The Sun itself, which is so large that its volume is 600 times greater than everything in the solar system combined, is less than one-trillionth of a percent of the entire solar system’s volume. There’s so much empty space in our solar system that it’s impossible for the human mind to truly grasp it.