‘The solar system consists of the sun and its nine planets.’ All of us read this statement in our schools in a chapter named ‘The Solar System’. And then, all of a sudden, in the year 2006, this became false when Pluto was demoted from ‘planethood’ and put under the category of dwarf planets. Only, it wasn’t done very suddenly, but the debate started long ago in the year 1992. Let us learn a few interesting facts about Pluto.
- Pluto was discovered in 1930 by a young research scientist Clyde Tombaugh. His ashes are aboard the New Horizons, the first spacecraft to fly by Pluto.
- Pluto was given its name by an eleven-year-old girl from Oxford, England. She proposed the name of the Roman God of the underworld.
- Pluto is the largest dwarf planet and the second heaviest after Eris.
- There are 5 known moons of Pluto, which itself is smaller than many moons of the planets in the solar system, including ours.
- The spacecraft New Horizons flew past Pluto in 2015 and sent a series of images along with other data. One image shows a heart-shaped patch on its surface spreading across an approximate 1,000 miles. There are no features inside the heart, it is estimated to be going through some geological process.
‘Three billion miles away, Pluto has sent a “love note” back to Earth, via NASA’s New Horizons spacecraft.’
- It is a member of the Kuiper belt, a belt similar to the asteroid belt between Mars and Jupiter. It is currently being studied and is thought to be a store of information on the makeup of the earlier solar system.
- Light from the Sun takes about 5.5 hours to reach Pluto as against 8.3 minutes it takes to reach the Earth.
- The concept of intersecting orbits of Neptune and Pluto is very interesting. From 1979 to 1999, Pluto was the 8th planet from the sun. They swapped orbits in 1999. However, there is no chance of collision between them due to various reasons. The travel paths of both bodies being tilted to each other is one of them. Also, due to the size difference between Neptune and Pluto, either of their speeds decreases when they come close to each other, ensuring that there is no chance of them colliding with each other.
- Pluto has an atmosphere! Yes, when it goes nearer to the sun, the heat vaporizes the frozen blocks of methane, nitrogen and carbon monoxide on its surface, forming a temporary atmosphere. When it goes back farther from the sun, they freeze back to their original form.
- In 2006, the International Astronomical Union formally gave the definition of a planet, which led to the removal of Pluto from the list of planets in the solar system. So, we only have 8 planets in our Solar System now, which are, Mercury, Venus, Earth, Mars, Jupiter, Uranus, and Neptune, in the order in which they orbit the sun.
We miss you, Pluto!
Image Sources: Wikipedia, Shirt.woot, NASA, New Horizons