The images of Pluto sent back by the New Horizons space probe have captured the attention of the world.
It's something I've been looking forward to for over 20 years, and it looks like I'm not alone.
I was born at the start of the 1980s and became fascinated by astronomy towards the end of the decade. By that time, space probes had visited every planet – except Pluto.
Now we finally know the simplest thing: what it looks like.
Before we go any further, let me get something out of the way. I am fully aware that Pluto is now classified as a dwarf planet, not a "proper" planet. I'm not trying to question that. I'm using the word "planet" simply because, when I first became fascinated by space, Pluto was classed as a planet, so that's how I thought of it. As a popular page on Facebook puts it, "When I was your age, Pluto was a planet".
Until the last week, Pluto has been the one big enigma in the solar system. In my first astronomy books, it was the one "planet" that only merited a page or two because there was so little to say.
It was also the only one that wasn't illustrated with big colour photos.
Instead, the images were often no better than the ones astronomer Clyde Tombaugh used to discover Pluto back in 1930.
These two shots were taken six days apart, during which time Pluto gave itself away by moving slightly against the stationary background stars. The arrows show where it is in each photo.
That was about all Tombaugh had to work with, and for decades that was all any of us saw of Pluto.
Each of the eight other planets – or just "eight planets" as they are now – was a distinct world. Venus with its searing heat, crushing pressure and constant acid rain. Mars with its dramatic red hue. Jupiter with its streaming bands of colour and grab bag of moons, from volcanic Io to icy Europa. Saturn, of course, had its rings. Uranus was inexplicably upside-down. Neptune was a deep, cool shade of blue.
But Pluto was just a dot, and doomed to stay that way.
Even the Hubble Space Telescope couldn't do much with it. The Hubble is famous for producing staggeringly detailed images of deep space, like this celebrated shot:
In 1994 it took this image of Pluto and its largest moon Charon. Feel free to be underwhelmed.
Some years later it took a series of shots, which scientists overlaid to produce this map of Pluto – although you may feel that "map" is not quite the right word here.
Now we get to see it in full colour and high resolution, for the first time. It is, quite literally, our first look at an entirely new world.
Since the Neptune flyby in 1989, the space programme has made plenty of discoveries. A string of rovers have explored Mars, the Cassini probe has toured the moons of Saturn, and MESSENGER gave us our first complete map of Mercury. Perhaps most impressively, the Philae lander touched down on a comet.
But for me, there's nothing quite so thrilling as seeing something utterly new for the first time, after a lifetime of waiting.
Here it is.