The planet Uranus is spectacularly far away. Even when viewed from Saturn, the next planet in, icy Uranus is still just a few pixels of blue in an inky black sky. This photo was taken by NASA’s Cassini spacecraft while the probe was 2,659,800,000 miles away from Uranus.
Here, Saturn’s A and F rings arc across the foreground. Uranus is in the upper left. With the equivalent of 14.5 Earth-masses of material, the planet is considered an ice giant (its neighbor Neptune is, too) since it’s primarily made of water, ammonia, and methane ices. It looks blue in photographs because the methane in its atmosphere absorbs red wavelengths and reflects blue.
Like Saturn, Uranus has rings and moons. But unlike Saturn — and indeed every other planet in the solar system — the ice giant is tipped on its side. In other words, rather than spinning like a top as it circles the sun, Uranus rolls around on its side. It’s not exactly clear why this is the case, but one of the more popular theories suggests that early on, a pair of giant impacts pummeled the planet and knocked it over. This strange configuration isn’t the only enigma in cool, blue Uranus’ clutches, though: The planet’s moon Miranda is one of the strangest objects in the solar system, a tiny world that looks like it’s been blasted apart and put back together again.