Pluto is just the beginning
Short answer: Because we changed the definition of the word “planet” to better fit its meaning.
And he thinks the upcoming flyby will prove it
New Horizons scientist Leslie Young discusses what to expect from the flyby on Tuesday, and the 28-year wait leading up to it
Short answer: It depends who you ask
Scientists aren't just jerking you around—this is about something more than your childhood nostalgia
How skeptical should we be, and how will we find out if this mystery planet is really out there?
It could be something even cooler.
Countdown: 45 years left until 'First Contact'
Starving stars are more common than intelligent life
Hawking's posthumous paper is more like a ruminative twist on multiverse theory, but that's just fine.
Space sailors' delight?
Beta Pictoris is the ultimate family man ... er, star
Cathy Olkin talks about what New Horizons has seen and where it's going next
Bubble, bubble, toil and trouble
Scientists are hot on the trail of our solar system's 9th planet
An 'Oumuamua by any other name would still be as fascinating.
Google's Lunar XPrize just announced new prizes.
Popular Science goes way back
Charon is the real #SuperBloodMoon in latest New Horizons pics
What will we find when we reach Pluto and Ceres? We don't know, but it's going to be wild.
This year's missions to the outer solar system are set to shake up the planetary family tree
The first color movies from New Horizons show Pluto and Charon in a weird waltz
Could icy slush be driving the dwarf planet's geological activity?