Pluto True Colors

Pluto Facts 101 – Enter to the Mysterious World of Pluto

Beginning Of It All – Pluto Facts

Awakening of Pluto facts!

It was dark, cold and night (as it used to be ever) approximately 4.5 billion years before now while the seeds of the baby planet Pluto were planted.

Thanks to gravitational facts, a chaotic and epic process triggered particles hanging around. They decided to get together and patiently formed a star system. This led to a long journey of slow but massive collisions. This beauty was about to be born and formed:

Beautiful Planet Pluto. Source: NASA

Pluto Facts – How Was Pluto Formed?

The obscure history

It’s always hard to go 4.5 billion years back and simulate every single incident happened in our Solar System. Same applies to other tiny little corners of universe as well. But if we had to stick only with what we see or directly observe, science would definitely be crawling.

Luckily, some great scientists made things easier! We can calculate the effects of gravitational forces, analyze planets surface and atmospheric features and make proper predictions.

Unlike the other ideas, this mighty planet is not a runaway from another star system. We are pretty sure that she is not our world’s step sister. Pluto was one of the objects sent away from Sun to Kuiper Belt and fitted to its bizarre orbit billions years ago. And we believe above incidents took place on initial “millions” of years of solar system formation.

Formation of Planets
An illustration of planet formation process. Source here

During this period, the planet had various different structures in time till the collisions with big masses (like other planets) ended. Than she got her rounded shape after having a stabilized orbit and rotation. Meanwhile, the radiative effects of Sun together with planets’ atmospheric and internal progression ended up with her current structure.

Pluto Facts – How Does Pluto Work?

Pluto Facts: Basic Definition

We define Pluto as a Trans Neptunian rounded and icy object. She is mostly located in Kuiper Belt with a highly eliptical orbit around Sun. Planet Pluto has been called a dwarf planet for some time, but some brave heart astronomers still call her a planet.

Here are some more Pluto facts in details:

Pluto Facts: Pluto’s Orbit and Rotation

This naughty sphere has a quite strange orbit comparing to other regular planets in the solar system. Instead of having more ecliptic orbit like the other regular planets, our buddy has a tilted orbit (about 17.14 degrees) with respect to Sun’s ecliptic plane. This titles her as one of the planets with most eccentric orbit in our solar system. We thought she was number 1 until other planets like Eris and Sedna were discovered. But now we know that’s not the case.

Another orbital oddity of Pluto is, unlike other planets she rotates around Sun while its north pole is upside down.

Pluto’s orbit is so eliptical that she can sometimes be closer to Sun than Neptune.

Below is a sketch highlighting some interesting information about different events happening while she is orbitting Sun.

Pluto Orbit
Pluto Orbit and Major Events. Source: JHU APL

In addition to above, Pluto is in 2:3 orbital resonance with Neptune. That means, as Neptune completes three tours around Sun, Pluto performs two tours. This period takes about 596 years.

Pluto Facts: Where Is Pluto In Solar System?

Where is Pluto? Is Pluto In Solar System?

It’s possible but hard to formulate 100% correct momentary coordinates. And this is similar for any celestial object since all objects are destined to move in the universe. But yes, she is luckily still in solar system! It is always fun and at least gives a basic idea to click this NASA link to track how far she is to Sun currently.

As a result of her eliptical orbit, her distance to Sun varies between 4.4 billion to 7.4 billion kilometers depending on the position in orbit. Considering an average distance of 5.9 billion kilometers to the Sun, photons leaving Sun will reach our planet in 5.5 hours in average. This also means, what we see with our telescopes is how Pluto looks like 5.5 hours ago.

Pluto and Charon: Ancient Partners of Cosmic Dance Floor

One of the interesting Pluto facts is, she has a “spin-phase lock” with the moon Charon. While our moon (The Moon) is tidally locked to our Earth and we can only see the same half; Charon and Pluto are mutually tidally locked to each other. This means; if you were on wrong side of Pluto, you might be so unlucky to never see Charon.

Did you ever hold hands with your friend and turn around each other until falling down? This is the way Pluto and Charon dance each other around a mutual gravitational center (barycenter), where one scene is completed in about 6 days and 9 hours.

Pluto Charon
Pluto and Charon orbiting Pluto System’s barycenter. Credit: Stephanie Hoover / Wikimedia

Some of you might think that if you are accomodating on the lucky side of Pluto, you’ll have more fun with solar eclipses when Charon blocks sunlight.

Pluto Facts: Eclipses

Well that’s true, however it won’t be that fun. Yes, solar eclipses will happen and you’ll have a remarkably big chance to catch them. But no, it will not be as dramatic as you experienced before.

Umbrella Picture
Some of you have been clapping a satellite for blocking sun light. Fellows.. Have you ever clapped a beach umbrella?

Basic reason is, around Pluto-Charon System, the Sun shines about 1000 times fainter than it does on Earth. You can consider the brightness on a sunny afternoon similar to that on the edge of sunset on our planet Earth.

Considering the huge distance from Sun together with the size ratio about ¼, Charon will shadow up to quarter of Pluto surface on a full Sun eclipse.

Charon as seen by Pluto
Illustration of a scene from Pluto land right after an eclipse. Credit: NASA/Southwest Research Institute/Alex Parker

Structural Pluto Information

Pluto Facts – Size Analysis

Some more Pluto facts about size:

According to latest and the most accurate data gathered during New Horizons’ Pluto flyby, Pluto has a radius of 1.188,3 kilometers. Comparing to the Earth, this means 1/6 of width. In other words, approximately 170pcs Plutos will fit in Earth. 3pcs of them will easily fit in our Moon.

For a better understanding of size: Slice this sad planet in half with a hypothetical huge knife. The inner surface area of the hemisphere will approximately be as half big as of Brasil lands. Doesn’t sound that big huh?

Do not try slicing planets at home!

Pluto Facts – Gravity and Surface Temperature

If you decide to visit Plutoland one day and do not count the time it takes to arrive (remember tiny New Horizons Spacecraft travelled more than 9 years), you’d feel pretty light once you land on the ground since the gravity is 1/16 of Earth.

If you decide to visit Plutoland“, yeah. Because you wouldn’t want to be there in case you don’t have suicidal tendencies.

One of the deadly Pluto facts together with extreme storms and hazardous effects of solar winds is the surface temperature which varies between -238 to -218°C. Researchers believe this might slightly increase as Pluto comes towards the sun.

The basic reason for the low temperature onboard is, as you can predict, the huge distance from the Sun. Plus the atmposhere is quite loose and the atmospheric structure is not being very helpful to increase surface temperature.

Pluto Facts – Surface Composition

98% of the planet surface consists of nitrogen ice. And rest of the items seem to be methane, carbon monoxide and water ice. For more details about structural information, see relative article elaborating Pluto surface and beyond.

But what’s inside? Did you check when you chopped her in half?

Pluto Inner Layers
For a long time, scientists believed the inner layers beyond surface were basically as above. Source: Wikipedia

We used to know that there’s a dense and rocky core which is about 70% of the diameter. And it is covered with water ice, which is trapped in between core and the surface.

Pluto Facts – The Underworld Ocean

This is basically correct, there is big amount of water on Pluto however some of the layers might be missing.

Instead of above, the recent studies in 2019 show that there’s a great possibility of a hidden ocean over there! Below the water ice layer covered by frozen nitrogen, there could be a source of a big amount of liquid water as well!

Pluto inner layers
Latest studies of planetary scientists exposed that there might be more layers, including a subsurface ocean. Photo source here

However, this is only a possibility yet and is dependent on couple of requirements. More details about those requirements are on our detailed article: Pluto ocean.

Pluto Facts – What Color Is Pluto?

From the famous reddish and best image of Pluto taken by New Horizons, we can see the basic colors of Pluto are shades of red together with white. This means we observe the icy particles together with the red areas, which are the tholin layers above the surface materials. However, if you arrange a closer approach and use your bare eyes instead of spectrometers, real Pluto color you’d observe would mostly be shades of brown and yellow.

Pluto True Colors
Re-processed version of New Horizons image in true Pluto color. Source: NASA

Since that red colored photo is taken by a camera with additional infrared view functionality for scientific purposes, the red scene pops up. But that is kind of deceiving.
It should naturally look like above. Those are the true colors of Pluto.

Pluto Facts – Atmosphere and Magnetic Field

Researches show that there’s a tiny or no magnetic field of Pluto. However, there is an existing atmosphere.
Pluto atmosphere includes similar materials with the planet surface and the atmospheric pressure is 100.000 times less than ours, where the average thickness of the atmosphere is remarkably big comparing to Earth.

Pluto clouds
We didn’t know what this sad planet was hiding. Stunning clouds and atmospheric haze. from New Horizons Spacecraft. Source: NASA

Pluto images were also captured by New Horizons Spacecraft while she was located on the opposite side of the Sun. Processing of those images showed us that the color of Pluto atmosphere is blue, similar to Earth. Scientists believe this is a direct result of sunlight occultation of materials in atmosphere like methane and hydrocarbones.

Pluto Atmosphere
Picture of sparkling atmosphere while Pluto is behind the Sun. This was one of the most important phases of New Horizon Mission for a better understanding about the atmosphere. Source: NASA

Pluto Facts – Surface Features

Recent studies show that, because of the cooling effects of methane in her atmosphere which increases the atmospheric density, rivers of liquid nitrogen might be observed in the past and future depending on slight temperature increases. A minimum -210ºC will be enough for that. Since that was not the case in 2015, we could only observe mountains and valleys:

Pluto Surface
Looks like a satellite picture of a rocky place from Earth? Nope, it’s from Pluto surface! Source: NASA

We can also see clear signs of craters on several locations. No dense atmospheres to mangle asteroids, yes enough amount of mass to pull them: No surprise at all!

See Pluto Map article for details of those surface features.
In addition, we have another article about the surface map of Charon.

Detailed analysis of those maps revealed that Pluto has a truely active surface which is frequently refreshed. Further researches revealed that the sources of the surface regeneration are processes like condensation, sublimation, thermal convection, winds, glaciation and cryovolcanism. Our Pluto surface article gives more information about above processes as well.

Although the surface images of Pluto gathered by New Horizons could only discover one of the hemispheres for all the world to see, a recent study also revealed more about the geology of Pluto’s far side via lower resolution images being processed. It seems the surface geology is similar to the encountered hemisphere, including more variations of above.

Pluto Craters
High resolution image of a crater area from New Horizons. Source: NASA

Pluto Facts – Does Pluto Have Rings?

As New Horizons Spacecraft crossed from inner parts of Solar System and reached to Kuiper Belt area, more Pluto facts were confirmed and some of them were disproven. Before New Horizons Mission, scientists believed that she might have rings similar to the gas giants in solar system.

However it turned out there are no Pluto rings at all! Instead of rings made of tiny rocks, new Pluto satellites were located while New Horizons spacecraft was wending on its way to Pluto.

Life On Pluto Planet

We have always searched for smart creatures outside the world and even set limits for increased possibility of complex life (like Habitable Zones).

We believe above mentioned tholins “might” lead to evolution of life. It worked down here after all! But for a proper (but primitive) alien life, more essentials needed: Reasonable temperatures, some oxygen and sufficient amount of magnetic field which should be combined with perfect balance.

Possible existence of liquid water is always exciting to hear and is very important for living organisms. We wouldn’t be surprised if signs of primordial life were unleashed on Pluto some day.

However, we are sorry to say that it’s pretty unlike to observe a smart Plutonian creature in near future.

Pluto Moons

Planet Pluto has 5 known moons named Charon, Styx, Nix, Kerberos and Hydra. You can get particular information for all from those links.

Pluto Moons
All Pluto Moons in same frame, after discovery of Styx. Captured by Hubble Space Telescope in 2012. Source: JHUAPL

While Pluto System consists of a planet and 5 Pluto moons, few astronomers tend to call Pluto and Charon as double dwarf planets as well. This is because of the similarity in dimensions and spin phase lock between each other.

Pluto and Charon have such a relation but on the other hand, small moons are not tidally locked to Pluto. Since they are respectively small and oddly shaped; their axial rotation is chaotic. However all moons have almost perfect circular orbits around Pluto.

As a result of their small size, smaller moons could not reach to a hydrostatic equilibrium. That resulted both with their odd shapes and simple formations as primitive rocks.

Pluto Facts – Discovery

Percival Lowell was the first person to estimate the effects of a ninth planet after discovery of Neptune. His calculations were mostly leading to a Planet X which we are still looking for, but lead to discovery of Pluto instead!

So humanity had to wait until 18 February 1930 when Clyde Tombaugh executed the discovery. The discovery took place in Percival Lowell’s observatory after Mr. Lowell died.

Clyde Tombaugh
Mr. Clyde Tombaugh at work. Source: Wikipedia

His method to detect planetary objects was simple but not easy: Recording astronomical photos to photographic plates every night, focusing on a specific area in the sky and searching for the objects which change positions in short time intervals (like days).

Although above methods sound simple and reliable, today we have great computerized systems and much more effective tools for detecting such objects; even for planets in other star systems.

Furthermore, he was definitely not the only person to look for Pluto with similar methods out there.. There were two more people to locate Pluto in 1925, however they failed to prove that before Tombaugh.

Who Named Pluto?

Venetia Burney, 11 years old during the discovery, had the chance to spread the word Pluto. She was into Greek mythology at that age.

Venetia Burney
Venetia Burney from 1930’s. Source: Wikipedia

A fun fact about her is, she received £5 in cash for her name suggestion. Considering the inflation rates from 1930 till now in UK, that’s not 2-beers money any more; but the cost of an average laptop. Well done and rest in peace Venetia!

Percival Lowell has also been hailed with the name PLuto since his full names’ first two letters are included.

Is Pluto A Planet?

Well, it’s time to ask more questions here: Why is Pluto not a planet? What happened to Pluto? Is Pluto alright?

Here comes our sad story.

It Was All Eris’ Fault!

First of all, take it easy; she is doing fine.

Eris and Dysnomia
Planet Eris and Moon Dysnomia. Source: NASA

It has been more than 4 billion years since Pluto was formed. She has been exposed to thousands of impacts, but never been accused of being something other than a planet ever. But here we are!

Discovery of planet Eris (named temporarily as: “2003 Ub313” those times), which is in Sun’s orbit in Kuiper Belt region and similar in size, has triggered astronomers to reconsider the definition of a regular planet. Thus on 24 August 2006, IAU (International Astronomical Union) made an announcement.

With the exact words of IAU, only reason for Pluto and many others named as “Dwarf Planets” from this date is: “They did not clear the neighbourhood around their orbits”. New classification was found controversial by many and still on debate.

Can Pluto Be A Planet Again?

Although majority of astronomers and media stick with IAU’s official definition, there are some astronomers and planetary scientists still questioning IAU’s definition. After years of debate, an alternative (geophysical) planetary definition was announced by planetary scienists in 2017. They have solid and convincing arguments which might change global outlook on planets, however there are no such considerations on IAU side.
Despite above, we believe there’s always a chance that Pluto and other despised planets will be called as ordinary planets again.

Dark side of Pluto
Blame her for not being a planet and see the dark side of Pluto! Source: NASA

Pluto In Astrology

Pluto, its size, distance to Earth, gravitational effect or any other attribute has nothing to do with your horoscope, your daily life or anything else about your mood. This is common for any planet, star and cosmic object you can think of in the universe.

Astrology means fairy tales.

Astronomy relies on facts; on a thing we named in last few centuries: The Science.



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  1. Laurel E. Kornfeld September 5, 2019
    • Plutopic September 5, 2019
  2. George W. Branchaud, Jr. July 17, 2019
    • Plutopic July 20, 2019
    • Laurel E. Kornfeld September 5, 2019

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