Why is Pluto no longer a planet?
Pluto has been removed from the list of planets just because:
Pluto hasn’t been a planet since, like, 2006, so it’s time to move on. Pluto was demoted at the 26th general assembly of the International Astronomical Union in Prague in 2006, and it was a controversial decision. There were astronomers who wanted to keep it, but the only argument they could make was tradition. There was, and is, no scientific justification for calling Pluto a planet. It’s a thing out there in the Kuiper belt which is like the asteroid belt, only it’s out past Neptune and it’s a lot bigger. There are about a trillion things in the Kuiper belt. A million things, And nearly all of those things are chunks of ice and rock, like Pluto. Pluto is just the first one that we saw And Pluto is pretty big for one of those things, but it’s not the biggest thing in the Kuiper belt. That title goes to Eris which is about 25% bigger by mass and twice as far from the sun as Pluto. There are other big things too, like Haumea and Make make and Ceres, which is in the asteroid belt between Mars and Jupiter, making it practically a local.
Scientists predict
that there may be up to a hundred other big things out there in the Kuiper belt just waiting to be discovered. But having over a
hundred planets would have made those songs and
sayings we learned in elementary school really, really long. And that’s really the crux of why we had to downgrade Pluto because if
we call Pluto a planet we’d have to call so many
other things planets too that the word planet would stop being useful So in
2006, astronomers decided that to be a planet an object had to: orbit the sun have
enough gravity to pull itself into a more or less spherical shape, and have
cleared pretty much everything else out of its
orbital path. The last one is where Pluto falls short Pluto is only 0.07 times
the mass of everything else in its orbit. Earth, just to give you some sense of perspective, is 1.7 million times the
mass of everything else in its orbit. But the International Astronomical Union
wasn’t completely heartless. It came up with a new category
of celestial objects that satisfies only the first two criteria. We call them dwarf planets. And in honor of this special place
Pluto holds in our hearts, they decided to call
all dwarf planets past Neptune plutoids which is… It’s pretty sweet. And the
same year astronomers decided Pluto could no
longer be considered a planet, NASA launched the New
Horizons spacecraft with a mission of visiting Pluto. New Horizons will do a
dramatic fly by of Pluto and its moons in July
of 2015 and send back lots of photos and information that
will tell us more than ever about our favorite little dwarf planet.
Share your opinion below on comment section.
0 comments: