Is Pluto a planet?

Last year, astronomers publicly announced that Pluto isn't a planet anymore. It wasn't able to fulfill the guidelines. Therefore, the solar system is now composed of eight planets.

The International Astronomical Union has removed Pluto its planetary status which it's had since it was discovered in 1930. The definition of what makes a planet a planet has been updated and pretty much different from Copernicus’ labor of love.

New regulations state that a planet is defined as a celestial body orbiting around the sun. It must have a sufficient mass in order to gravitate itself and to overcome the body forces. Therefore, its orbit must be of a round shape.

At a conference consisting of 2500 astronomers who came from a total of 75 countries, demoting Pluto was a plan that was popular. It also declared two objects cruising around Pluto as dwarf planets. These are Ceres, an asteroid, which was discovered in 1800s and 2003 UB313 also known as Xena, an icy object that is a bit bigger than Pluto. Meanwhile, Charon, which is the largest moon of Pluto, won't be considered for another designation.

This discussion resulted to an agreement that basis tests must be undergone before a celestial object is considered to be a planet. Such talk is necessary because admitting to being a planet is like becoming a member of a cosmic club for the elite.

At the moment, there are only eight planets in our solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn and Uranus. So what will now happen to the popular phrase concocted “My Very Earnest Mother Just Served Us Nine Pizzas?” (This is a way for students to remember the solar system.) Will it now be shortened to “My Very Earnest Mother Just Served Us… Now?

Pluto was disqualified because it has an oblong orbit which overlaps that of Neptune’s. This being the case, it is classified as a “dwarf planet” also known as “minor planets.” This new definition also led to another class of lesser objects orbiting the sun. The third class is deemed as “small solar system bodies.” The examples are comets, asteroids and natural satellites.

The demotion of Pluto from planet to dwarf planet has repercussions. It can affect NASA’s New Horizons mission. This is the 961/27 year travel to Pluto in order to discover it further.

It’s just ironic that for decades, Pluto, which is farthest from the sun, was nicknamed to be the smallest planet because of its pint-size. This debate has been ongoing since the argument that Pluto is only one four-hundredths of the total mass of the planet we’re living on which is Earth.

But it pretty much remained to be the ninth planet because it was the only object residing within the Kuiper Belt or the disc-shaped zone wherein thousands of planetary objects and comets gravitate.

In the 1990s, it was confirmed that the Kuiper Belt contained several other bodies that are similar to Pluto. This triggered doubts among scientists: on whether Pluto really is a planet or merely an object?

Then this debate heated further when Michael Brown and his colleagues discovered a celestial object that is bigger and further away from the sun, compared with Pluto. This is the UB313 which was measured by the Hubble Space Telescope at 2400 kilometers in terms of diameter. Plus, it is 710 kilometers longer when set alongside Pluto.

Now, it has sealed its fate – it isn’t a planet anymore. At least this announcement is exciting. Pluto has long been the center of contention amidst groups of astronomers because of its different way of orbiting the sun.

The only adjustment we have to do is how to educate children. Which brings us back to the sentence mentioned earlier which helps them recall the structure of the solar system.

“My very earnest mother just served us now.” No more nine pizzas. No need for the word pizza to represent Pluto because it is no longer a major planet despite all the debates and contentions it has sparked throughout a number of decades.

Nonetheless, the solar system will be explored further in order to uncover the interesting celestial bodies and objects flying out there.