Unending Debate Over Tiny Pluto

We're not sure who designated it, but today, February 18, is Pluto Day. No, it's not a celebration of all things dog with the Disney character and Mickey Mouse's companion, Pluto. It is a day for the smallest planet of our Solar System - Pluto.

The Pluto Debate

Officially, Pluto is known as a "dwarf planet," following a huge debate about whether it was a planet in the first place. That was in 2006, when official designation was stripped away from the little ball, which indeed has a very odd elongated orbit around the Sun. It's not the same distance from the Sun and the orbit takes it out past the orbit of the distant gas planet Neptune and then brings it back inside Neptune's orbit. That was one of the reasons the "planet" debate raged on. The orbit takes it into the Kuiper Belt of asteroids that surrounds our Solar System, with some asteroids at a size that at least equals Pluto.

Pluto's Interesting Features

However, on July 14, 2015, the New Horizons spacecraft from NASA cruised on past Pluto and found a few things scientists were not expecting. Initially, it confirmed that there indeed was a moon named Charon around Pluto. Since then, as many as five have been determined. And, as New Horizons passed behind the dwarf planet, it took a photo of a thin blue haze around it - an atmosphere. That's not the usual thing you see around an asteroid. The atmosphere is made up of nitrogen, methane and carbon monoxide. Even our Moon, which is a little bigger than Pluto, doesn't have an atmosphere.

All that has led to Pluto Day, where interested folks, including quite a few in Montana, want to return Pluto to regular "planet" status. So, instead of eight planets and a dwarf planet, they'd like to return to how kids always learned about the Solar System - nine planets. Mercury, Venus, Earth, Mars, Saturn, Jupiter, Uranus, Neptune...and Pluto.

And, as far as being cold this winter (next week, especially) Pluto has much lower temperatures. How about minus 378 degrees F?