Pluto Facts For Kids | A Dwarf Planet

Pluto is the only planet that was discovered in the 20th century. Pluto was moved down to the status of a dwarf planet in 2006, which makes it even more interesting to study this planet. So let’s have a short but interesting journey of this mysterious dwarf planet in Pluto facts for kids.


Clyde Tombaugh discovered Pluto in 1930. He was an American astronomer. Tombaugh was only 24 at the time of discovery.

How Was Pluto Discovered

Following the discoveries of Uranus and Neptune, at first Pluto was thought to be the third planet as other 6 planets had always attracted the eyes of keen observers for many years. These six planets were noticeable to the unaided eye which is why ancient people knew them. On the contrary, the existence of Pluto was previously based on the assumption that the circular path of Uranus was seemingly disturbed by another body that is quite far-off. However, this assumption was proved to be wrong because the size of Pluto is too small to cause any such disturbance. At the start of 20th century, an astronomer from USA named Percival Lowell built an observatory at Flagstaff, Arizona and set off to explore Pluto. But in 1916, he died without achieving any success. In 1929, a young astronomer named Tombaugh was signed up to this task and continued the search by means of a specially-built camera. At last Tombaugh discovered Pluto in February 18, 1930.


The diameter of Pluto is more or less 2,284 kilometers. Moon (which is the only satellite of our planet) is bigger than Pluto. Pluto is about two-third the size of our Moon.


Observations of this planet reveal that its color is somewhat red but unlike Mars which has a more reddish surface, it is only moderately red that shows the planet is not just made up of ice.


Pluto requires 247.7 earth years to complete its orbit around the Sun.


Pluto is located in the Kuiper Belt. Kuiper belt is found away from the last planet of our solar system; Neptune. This belt is made up of rock and ice formed of the fragments that were left behind after the solar system was formed.


Pluto lies at an average distance of 39.5 AU (Astronomical Unit) away from the Sun. One AU is equal to 150 million kilometers (which is the distance between the Earth and the Sun).


The mass of Pluto is about 1.2 × 1022 kg.


The density of Pluto ranges from 1.92 g/cm3 to 2.06 g/cm3.


The core or the innermost part of Pluto is assumed to be made up of rocky material. The mantle layer wrapping it up is perhaps made up of thick water ice. The outermost part of Pluto is made up of methane, nitrogen and carbon monoxide in ice forms.

Moons Of Pluto

Pluto has 5 moons; Charon, Nix, Hydra, Kerberos and Styx. Discovered in 1978, Charon is by a long way the largest moon of Pluto. Its size is about half that of Pluto and orbits the planet at a distance of about 19,640 km.


Pluto has a thin layer of atmosphere which was discovered in 1988. Scientists observed the atmosphere of Pluto when it passed a star and the light of this star slightly faded while it entered the planet and thus signaling the presence of atmosphere. When Pluto reached perihelion (a point from where Pluto lies at the minimum distance from the Sun) in 1989, many of its gases vaporized from the solid-icy state (a process known as sublimation) because it came closer to the Sun than usual. At aphelion (a point from where Pluto lies at the maximum distance from the Sun), it is impossible to examine its atmosphere because of the greatest distance from the Sun and thus lack of sunlight allows gases to solidify.


A very small amount of sunshine reflected from the surface of Pluto is referred to as Albedo. The albedo of Pluto is 0.55 (which means the surface of Pluto reflects back 55 percent of sunlight) and Moon’s albedo is 0.1 (meaning 10 percent of sunlight is reflected back from its surface). Because we do not know much about albedo as well as Pluto’s atmosphere, it is very hard to determine the precise surface temperature of this planet. However, it is estimated that its temperature varies between 45 K and 60 K.


The symbol used for Pluto is ♇. It is made up of two letters ‘P’ and ‘L’ that are merged into one letter. These two letters represent initials of the first two letters after the name of this planet (Pluto) as well as the initials of the name of the person (Percival Lowell) who initiated the project that led to the discovery of Pluto.

Interesting Pluto Facts For Kids

Pluto became a Dwarf planet on August 24, 2006 by International Astronomical Unit. It is no longer the 9th planet. Our Solar System now consists of only 8 planets.

It is by far the biggest of all objects lying in the Kuiper belt.

Pluto is the least studied planet in our solar system primarily because earth’s satellite has never been able to reach this planet.

The unusual behavior of Pluto’s orbit at times becomes so big that it takes this planet nearer to the Sun rather than Neptune. Pluto will not come any closer to the Neptune’s orbit up to the year 2226.

Charon is the biggest satellite of Pluto.

Because the rotational period of Pluto is equal to the speed at which Charon orbits around it, the side of Pluto facing Charon is always the same.

Pluto lies very far away so much so that it takes over 5 hours for sunlight to arrive at this planet though it travels at a speed of about 186,000 miles per second.

The Sun rises in the west of Pluto and sets in the east.

When Charon was not discovered yet, Pluto was believed to be the moon of Neptune that got away from its orbit for unknown reasons.

More Pluto Facts For Kids

The Sun appears like a very bright point from Pluto and looks a lot like a star. But the brightness of this point is so strong that a full Moon’s light is 100 times less intense than this point.

Pluto is invisible to the naked eye.

Pluto is not the ninth planet anymore. It is now a dwarf planet. Dwarf planets are smaller than Mercury (the smallest planet in our solar system).

Hubble Space Telescope discovered two new satellites of Pluto in 2005.

The point at which Pluto lies at the closest distance from the Sun is called perihelion. Pluto’s perihelion is about 29.7 AU. It was in 1989 that Pluto last reached its perihelion.

The point at which Pluto lies at the farthest distance from the Sun is called aphelion. Pluto’s aphelion is about 49.5 AU.

The surface temperature of this planet is freezing cold which makes carbon monoxide gas as well as nitrogen gas to exist in ice forms over Pluto.

Now that, how did you find these Pluto facts for kids? Are they really helpful and is it what you’re looking for?


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