Seems like we don’t pay much attention to the 7th planet.  We know it’s out there, and it’s blue (but not as blue as Neptune).  We know it’s cold, and a gas giant, and … well … it’s cold, and blue, and it’s the 7th planet…

NASA/JPL, Voyager II 1986 image of Uranus

While it’s not a media star like Jupiter and Saturn, and doesn’t even get the attention Neptune and Pluto receive, Uranus is certainly no slouch when it comes to beauty or mystery.  While the 1986 Voyager II image is wonderful (lovely, startling, mysterious, remote), the Hubble has been showing us some even more breath-taking views of this magnificent giant.  Take a look at this:

This of course shows the rings and moons of Uranus, along with the false coloration to show altitude and atmospheric features.  And speaking of those rings, William Herschel (who discovered Uranus) described a possible ring system around the planet in 1789.  For the next 200 years, nobody else saw the rings around Uranus until 1977, when they were “discovered”.  We have so far counted 13 rings in the Uranian system, and 27 moons.  Quite a complex system.

Uranian ring system with inner moons, Image in public domain

Uranus has an axial tilt like none other in the solar system; it’s almost 98 degrees, making Uranus “lay over” on its side.  Its poles are positioned where its equator should be.  Scientists speculate that the dramatic axial tilt was caused by Uranus being impacted with an Earth-sized protoplanet early in the life of the solar system.

NASA/JPL Uranus/Earth to scale - Uranus showing true color variation

Although Uranus is visible to the unaided eye, just barely, it was not recognized as a planet because it’s so dim and its orbit is so slow.  It was the first planet to be discovered by telescope, March 13, 1781, but William Herschel thought he had discovered a comet or a new star.  It takes Uranus a little over 84 years to complete an orbit.  With the way its axial tilt works, each pole spends about 42  years in either total darkness or total sunlight.  Of course, Uranus only receives a tiny percentage of the sunlight the Earth receives.

NASA/ESA Hubble ST 2005, Uranus, natural color, showing rings and clouds

I’ve barely touched the surface of the mystery and beauty of our 7th planet.  We all knew it was out there, but hopefully we’ll take a longer look at this ancient Greek god of the sky.  It’s certainly worth our awe and our interest.