Hello, Pluto!

On July 14, 2015, the New Horizons spacecraft whizzed by Pluto about 12,500 kilometers (roughly 7,800 miles) above the surface. The photos and data it sent back have changed how scientists see the dwarf planet — and given them many more mysteries to solve. Check out our new stories along with our older, archived Pluto coverage.

Visiting Pluto: A history of where the Pluto story began.

Picture this: Pluto hearts us: The New Horizons probe whizzed by Pluto — and showed that Pluto has a heart. Or at least, a heart-shaped feature.

Weird Pluto gives up its secrets: Pluto is weirder than scientists had imagined, with varied landscapes, wildly spinning moons and volcano-like mountains that spew ice instead of rock.

Pluto hosts ice mountains, data suggest: As the photos come back to Earth, scientists are getting many surprises about our favorite dwarf planet and its moons.

Students sent instrument to Pluto: The New Horizons probe carried many instruments — including one made by student scientists to measure space dust.

Cosmic collision may have given birth to Pluto’s moons: Pluto’s four outer moons are packed together in nearly synced orbits. This suggests they formed in the wake of a collision.

Explainer: What is a planet? Over the years, definitions have changed several times. Most recently, those definitions evicted Pluto from planethood.

The trouble with Pluto: Removing Pluto from the list of our solar system’s planets is just the latest in an age-old debate about how many planets share our sun.

Pluto, plutoid: What’s in a name? Here’s how Pluto’s dwarf-planet status has spawned a new class of celestial objects.

Sizing up Pluto’s moon: How scientists got a gauge of the size of Pluto’s biggest moon.

Pluto’s new moon: Here, we find that Charon is not the dwarf planet’s only moon.

For more about New Horizons and the Pluto flyby, check out Science News’ live coverage of the mission.