All you need to know about the dwarf planet Pluto

Pluto was discovered by the American astronomer Clyde Tombaugh in 1930. For a long time, the existence of this celestial body was all we knew about it. Not surprising, because Pluto floats billions of kilometers away from us in the Kuiper Belt, at the very edge of our solar system, even beyond Neptune.

The age old question: Is Pluto a planet?

For decades, Pluto was referred to as the ninth planet of our solar system. That changed in 2006 when the International Astronomical Union (IAU) decided to designate Pluto as a dwarf planet from now on.

Although Pluto is actually just a dwarf in space compared to large gas giants like Jupiter and Saturn, its size was not the main reason for the new classification. A celestial body must meet a number of criteria to be classified as a planet. For example, it must revolve around the Sun, be spherical, and “sweep” its orbit in space under the influence of its own gravity.

Shortly after the turn of the millennium, astronomers came to the conclusion that Pluto did not meet the criteria for the last planet. In addition, there are so many celestial bodies floating in the Kuiper Belt that are comparable to Pluto, all of which should be classified as planets. In 2016, a new category was created: dwarf planets. This includes, for example, Eris, a neighbor of Pluto in the Kuiper Belt.

New Horizons mission to Pluto

Pluto may not be a fully developed planet, but it remains a fascinating object in our solar system that we still know relatively little about. Pluto is so far away from us that it takes years to reach the dwarf planet. NASA’s New Horizons spacecraft was launched on January 19, 2006 and didn’t reach Pluto until July 14, 2015. It was the first spacecraft to orbit Pluto and take close-up pictures of the dwarf planet.

Dwarf planet Pluto

Close-up of Pluto taken by the New Horizons spacecraft.


This pioneering mission has yielded a wealth of new information about the far reaches of the solar system. Turns out, Pluto is a little bigger than we thought. New images from the New Horizons space probe also show how active Pluto is. The dwarf planet’s landscape appears to include glaciers, craters, floating mountains, and frozen lakes. Evidence of geological activity has also been found in Charon, Pluto’s megamon.

Is life possible on Pluto?

Therefore, the surface of the dwarf planet has some similarities with that of the Earth. Yet it is According to NASA, life is unlikely to be possible on Pluto. This has to do with the dwarf planet’s extremely cold temperatures: on Pluto it averages between -228 and -238 degrees Celsius.

It is not surprising that it is very cold on Pluto, because the celestial body is on average 5.8 billion kilometers from the Sun. As a result, the years on Pluto are also much longer than on Earth. The dwarf planet orbits the star in 248 Earth years. A day on Pluto also lasts much longer than we are used to: about 153 hours.

Pluto was named after the Roman god of the underworld, not after Mickey Mouse’s dog. In fact, Disney is said to have named the four-legged friend Rover, which was called Rover until 1930, after the orb to capitalize on the media attention this discovery brought.

Head shot by Williki van Dorn

Willicky Van Dorn studied journalism, traveled the world for a while, and eventually ended up working with the editors of Quest, National Geographic, and Runner’s World across the US, Australia, and New Zealand. Curious to know the world, she prefers to travel every month and always take her running shoes with her.

Leave a Reply

Your email address will not be published. Required fields are marked *