We never saw Pluto up close before. But NASA's New Horizons probe flew within 7,750 miles of it Tuesday morning — and now it's showing us the beloved dwarf planet and its five moons for the first time.
No spacecraft had ever been sent to Pluto, and because it's so small and so far away, we can't see it well with telescopes. So until very recently, the best photos of Pluto we had — taken by the Hubble Space Telescope — showed it as a blurry blob:
But New Horizons has changed that in a big way:
The spacecraft also showed us Pluto's five moons — including the largest, Charon:
This is the first photo ever taken of Pluto's tiny moon Hydra:
These photos are a long time coming. For years, NASA scientists fought for a Pluto mission but were unable to secure enough funding from Congress. During the 1990s, four different proposed Pluto missions were canceled:
Eventually, in 2003, their work led to the approval of New Horizons: a slimmed-down, lightweight probe that still carried a suite of seven scientific instruments to photograph Pluto, analyze its atmosphere, and tell us more about its surface geology:
The spacecraft was built at the Johns Hopkins Applied Physics Laboratory, in Maryland:
In 2006, the probe was launched from Cape Canaveral, Florida — traveling 36,373 miles per hour, faster than any spacecraft has ever left Earth. It was launched at this speed so it could reach distant Pluto in a reasonable amount of time:
It's since traveled more than 3 billion miles to reach Pluto:
In 2007, New Horizons swung by Jupiter, in order to use the planet's immense gravity as a slingshot toward Pluto. While it was there, it took stunning photos of the gas giant:
New Horizons was aimed at an extremely small target millions of miles away — so much so that mission scientists compared the feat of reaching the Pluto system to hitting a hole-in-one from across the country.
Apart from its scientific instruments, the spacecraft is carrying a number of interesting mementos, including the ashes of Clyde Tombaugh (the discoverer of Pluto), a CD-ROM with the names of 434,000 people who signed up for the honor, and a 1991 stamp that says "Pluto: Not Yet Explored."
As New Horizons got closer and closer to Pluto, it gradually saw the dwarf planet in higher and higher resolution:
It also began capturing detailed maps of Pluto's surface. It found mysterious light regions (perhaps caused by frozen methane or nitrogen) and dark areas (which could potentially be impact craters or volcanoes):
The flyby took New Horizons through the heart of the Pluto system, closer to the dwarf planet than its moons:
New Horizons will keep sending back information it's collected on Pluto for more than a year because it takes so long to transmit data. But the flyby itself was over after just a few minutes.
After traveling for 3 billion miles over nine years to show us a distant, mysterious planet for the first time, the tiny robot is continuing out into space — and for New Horizons, Pluto will soon be a tiny dot once again: