MU69 is far from your run-of-the-mill solar system object.
We're under a time crunch.
Short answer: Because we changed the definition of the word “planet” to better fit its meaning.
A good week for space photography
Is there a planet—or even planets—waiting to be discovered out there?
But we won't know until we get there.
Scientists aren't just jerking you around—this is about something more than your childhood nostalgia
This summer, the mission may get funding to travel to a mysterious rock at the edge of the solar system
How skeptical should we be, and how will we find out if this mystery planet is really out there?
Scientists are hot on the trail of our solar system's 9th planet
Cathy Olkin talks about what New Horizons has seen and where it's going next
Charon is the real #SuperBloodMoon in latest New Horizons pics
Short answer: It depends who you ask
Pluto is just the beginning
Stranger worlds to come
After nine years and three billion miles, here's what we're learning from it all
Even though I helped demote it
Witness history in the making
New Horizons scientist Leslie Young discusses what to expect from the flyby on Tuesday, and the 28-year wait leading up to it
And he thinks the upcoming flyby will prove 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
What's on the horizon for the New Horizons spacecraft