Ever since Pluto was demoted to a "dwarf planet" in 2006, I've been disgruntled about it. Back in my day, there were NINE planets, and to me, it will always be a planet.
New Horizons' flyby of the PLANET PLUTO supports a lot of astronomers' feelings about its status. And now, NASA Administrator Jim Bridenstine agrees that it should be re-promoted to planet status.
"Just so you know, in my view, Pluto is a planet. You can write that the NASA Administrator declared Pluto a planet once again. I'm sticking by that, it's the way I learnt it, and I'm committed to it."
And there you have it!
Of course the IAU has to get on board with it as well. However, after the controversial way that Pluto was demoted, it's still a long shot. On the last day of the IAU's conference in Prague in 2006, a vote was cast with approximately 10% of the 2700 attendees present regarding the criteria for how a planet is defined:
- is in orbit around the Sun,
- has sufficient mass to assume hydrostatic equilibrium (a nearly round shape), and
- has "cleared the neighborhood" around its orbit.
#3 has been the sticking point, and some claim that planets such as Earth and even Jupiter are not planets by definition as they regularly encounter asteroids that are orbits near theirs.
Some scientists are championing the cause to keep Pluto relegated to "dwarf planet" while others are in the opposite side. It's a battle debate that's bound to last for many years to come.
Whichever side you're on, you still have to admit, Pluto is a fascinating body in our Solar System.