New research provides some clues about our solar system's most mysterious planet.
Short answer: Because we changed the definition of the word “planet” to better fit its meaning.
And it could help prove the existence of Planet Nine.
Pebbles and planetesimals pummeled the planet's early surface
The survey also confirmed the existence of two other moons, whose discovery was announced last year
The lightning struck more than twice.
Our solar system's largest planet is a master of disguise.
Europa, the outer solar system, and a lot of questions.
Here are eight surprising things NASA has learned so far.
Giant planet orbits three stars at once
Let the science begin
The mission will give us our best views yet of the baddest planet in the solar system
Juno is closing in on one of the most dangerous places in the solar system
Juno will zoom in on Jupiter on July 4th
It starts orbiting the deadly planet in July
Here's the whole collection
Planet 2MASS J2126-8140 orbits a trillion kilometers out from its sun
Piping hot Jupiter fries, please!
The ocean-filled moon might hold the life we've long searched for in space. And scientists have one shot to reach it.
New Horizons scientist Leslie Young discusses what to expect from the flyby on Tuesday, and the 28-year wait leading up to it
This year's missions to the outer solar system are set to shake up the planetary family tree
The Dawn spacecraft arrives at Ceres this March, and it could be the most surprising space mission in decades