Pluto

NASA's New Horizons spacecraft captured this high-resolution enhanced color view of Pluto on July 14, 2015. The image combines blue, red and infrared images taken by the Ralph/Multispectral Visual Imaging Camera.

Pluto isn't a planet — but it gives us clues on how the solar system formed

Pluto hasn't been a planet for almost 20 years. In the early 2000s, scientists discovered several objects of a similar size to Pluto. So, during the summer of 2006, members of the International Astronomical Union convened in Prague to reconsider what counts as a planet in our solar system. IAU members decided that there were three criteria to be a planet — and Pluto did meet all of them.

But planetary scientist Wladymir Lyra says that even though it was downgraded to a dwarf planet, Pluto still has much to teach us about planet formation. This episode, he also lays out his case for Pluto — and many other objects in the solar system — to be considered a planet.

This episode is part of Short Wave's space camp series about all the weird, wonderful things happening in the universe. Check out the full series.

Questions about the state of our universe or smaller happenings here on planet Earth? Email us at shortwave@npr.org — we'd love to consider it for a future episode!
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Members of the New Horizons team celebrated last year with a blown up image of the postage stamp when the probe made its closest approach to Pluto.

Spacefaring Stamp Sets World Record

by Jason Slotkin

The "Pluto: Not Yet Explored" stamp has traveled farther than any other stamp, hitching a ride on the New Horizons space probe, which accomplished its closest flyby of the dwarf planet last summer.
The heart-shaped glacier on Pluto's surface is made of nitrogen, carbon monoxide and methane. Researchers aren't sure how it formed.

Distant Pluto Comes To Life

by Geoff Brumfiel

When a probe skimmed past the dwarf planet in July, researchers expected to see a cold, dead world. New results published today show that Pluto is an active place.
Pluto's atmosphere has a haze of blue, in this color picture taken by the New Horizons spacecraft that was released by NASA.

Why Is The Sky Blue? (On Pluto, That Is)

by Bill Chappell

Pluto's atmosphere has a blue haze, in a new photo from the New Horizons probe. But the particles causing that color are probably gray or red — and the planet's surface has red ice.

New Discoveries From NASA’s New Horizons Mission to Pluto

by Shawn Fitzmaurice

SciWorks Radio is a production of 88.5 WFDD and SciWorks, the Science Center and Environmental Park of Forsyth County, located in Winston-Salem.

On July 14th, NASA's New Horizons space probe raced past the dwarf planet Pluto at 44 thousand miles per hour. Loaded with an array of science instruments, the sturdy little probe gathered data which will be sent to us over the next 16 months. This episode was recorded before NASA's recent press conference, but keep an eye on http://sciworks.org/pluto for up-to-date mission information. You'll also find a special web-only episode about the mission, and details specifically for this episode. What have we learned from New Horizons since the encounter?

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How We Got To Pluto

by Shawn Fitzmaurice

SciWorks Radio is a production of 88.5 WFDD and SciWorks, the Science Center and Environmental Park of Forsyth County, located in Winston-Salem.

Launched in 2006, NASA's New Horizons space probe made its historic fly-by of the dwarf planet Pluto on July 14th. For regularly updated information about Pluto and its moons, check out http://scioworks.org/pluto. There you'll find a companion blog to this recording with links and details. For an update about the science coming in from New Horizons, check out SciWorks Radio on July 26th, to be archived at wfdd.org. 

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