From Milky Way reject to NASA’s buzziest new enterprise, Pluto is once again basking in the intergalactic spotlight.

Discovered in 1930 and dethroned as our solar system’s ninth planet in 2006, Pluto shot back to stardom this week as new images from NASA’s New Horizons mission revealed a slew of surprises.

Here’s a wrap of the new details we learned about the far-flung dwarf planet.

It’s got a big heart

A heart-shaped plain stretches about 1,600 kilometres across the planet. Dubbed the Tombaugh Regio after the planet’s discoverer, Clyde Tombaugh, the expansive geologic feature is marked by a cracked surface that resembles frozen mud.

And the region quickly became a hit on Twitter.

‘A mountain in a moat’

Pluto was known to be mountainous, but zoomed-in images revealed that a second chain of mountains cut through the planet’s heart-shaped Tombaugh Regio. (That’s Latin for ‘region’.)These rocky outcroppings are relatively shorter than the initial range, but nevertheless help researchers sketch a more accurate map of the planet’s surface.

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NASA scientists also got a better look at Charon, Pluto’s largest moon, and spotted an odd geological feature they call “a mountain in a moat.” The images show a mountainous peak poking through a surrounding crater. NASA hasn’t yet revealed exactly how the unique outcropping may have been formed.

Flowing ice

Calling the planet an “icy world of wonder,” NASA scientists announced Friday that Pluto’s surface is streaked with ice that bears similar properties to Earth’s glaciers. In the southernmost region of the Tombaugh Regio, scientists spotted ancient ice deposits that may be currently flowing.

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If true, it’s Pluto's first sign of modern geological activity.

“At Pluto’s temperatures of minus-390 degrees Fahrenheit, these ices can flow like a glacier,” said Bill McKinnon, deputy leader of the New Horizons Geology, Geophysics and Imaging team in a press release.

Hazy surprises

As the New Horizons spacecraft passed by Pluto’s dark side, it aimed its Long Range Reconnaissance Imager, or LORRI, back towards the sun.

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The resulting image shocked scientists. As sunlight passed through atmosphere, researchers noticed a haze extending as high as 130 kilometres above the planet’s surface. Further inspection revealed two distinct layers of haze: one about 80 kilometers above the surface and the other about 50 kilometers up.

This shattered previous calculations that Pluto was too warm to foster haze formations any higher than 30 kilometres above the surface.

“We’re going to need some new ideas to figure out what’s going on,” said Michael Summers, New Horizons co-investigator, in a NASA presser.

Now in living colour

Through state-of-the-art imaging processes, NASA has captured never-before-seen images of Pluto. By combining the LORRI images with colour data from the Ralph instrument, scientists have been able to piece together a more accurate image of the dwarf planet, which boasts shades of deep auburn, pastel pink and dusty red.

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“It reminds us that exploration brings us more than just incredible discoveries -- it brings incredible beauty,” said Alan Stern, the project’s principal investigator, in a press release Friday.