Pluto used to be known as the ninth planet in our solar system, but things changed in 2006. Scientists decided to redefine what makes a planet, and Pluto was reclassified as a dwarf planet. Let’s explore what makes Pluto special, how it moves around the Sun, and why it’s different from the planets we usually think of.
To understand why Pluto is called a dwarf planet, we need to know what makes something a planet. According to the International Astronomical Union (IAU), an object must meet three rules to be a planet:
1. **Orbit the Sun**: It must travel around the Sun.
2. **Spherical Shape**: It must be round because of its gravity.
3. **Clear the Neighborhood**: It must have cleared its path of other space debris.
Pluto does the first two things but not the third. It shares its space with other objects in an area called the Kuiper Belt, which is why it’s now called a dwarf planet.
Pluto has an unusual path around the Sun, called an elliptical orbit. This means sometimes it’s closer to the Sun and sometimes it’s farther away. On average, Pluto is about 3.6 billion miles from the Sun, which is 40 times farther than Earth! Sometimes, Pluto even gets closer to the Sun than Neptune does.
A year on Pluto is super long! While Earth takes 365 days to go around the Sun, Pluto takes about 248 Earth years. That means one year on Pluto is almost like two and a half centuries on Earth!
Pluto is incredibly cold, with temperatures ranging from -380°F to -400°F. It’s one of the chilliest places in our solar system because it’s so far from the Sun.
Pluto is quite small compared to other planets. Its surface area is smaller than Russia, and it’s even tinier than Earth’s Moon. If you weigh 120 pounds on Earth, you would weigh only 18 pounds on Pluto because of its low gravity.
People still talk about whether Pluto should be a planet or not. Right now, it’s called a dwarf planet, but as we learn more about space, this might change. Pluto is still an exciting part of our solar system, helping us learn more about the universe. Its unique features, like its faraway orbit, freezing temperatures, and small size, make it a fascinating topic for scientists and space lovers alike.
