In the early 1900s, astronomers were on the search for a ninth planet in our solar system. They had noticed peculiarities in the orbits of Uranus and Neptune that suggested the presence of another planet. This led to a massive search effort, as scientists combed the skies trying to find the elusive ninth planet. Finally, on February 18, 1930, the search came to an end. Clyde Tombaugh, a young astronomer at the Lowell Observatory in Flagstaff, Arizona, discovered a small, dim object moving across the night sky. It turned out to be the long-sought ninth planet, which was eventually named Pluto. The discovery of Pluto was a major breakthrough in astronomy, and it opened up all kinds of new questions and possibilities about the outer reaches of our solar system. But the story of Pluto's discovery is also one of perseverance, ingenuity, and a whole lot of luck. In this essay, we will explore the fascinating history of Pluto, from its discovery to its controversial reclassification as a "dwarf planet." Along the way, we will meet the people who made this historic discovery possible and learn about the many mysteries that continue to surround this enigmatic and fascinating celestial body.
Probing the Depths of the Solar System
The Search for Planet X
The discovery of Pluto is a fascinating story that spans several decades. In the early 1900s, astronomers were puzzled by irregularities in the orbits of Uranus and Neptune. They suspected that there might be another planet beyond Neptune, which they dubbed "Planet X." The search for Planet X began in earnest in the 1920s and involved some of the most prominent astronomers of the time.
Clyde Tombaugh's Discovery
One young astronomer who joined this search was Clyde Tombaugh. He was tasked with taking photographs of sections of sky over a period of several nights and comparing them to see if any objects had moved. After months of painstaking work, Tombaugh finally spotted a faint dot that had shifted position between two images - this was Pluto! On February 18th, 1930, he announced his discovery to the world.
Controversy Surrounding Pluto's Classification
For many years following its discovery, Pluto was considered to be the ninth planet in our solar system. However, as technology improved and more objects were discovered beyond Neptune (known as Trans-Neptunian Objects or TNOs), scientists began to question whether Pluto truly met all criteria for planetary status. In 2006, after much debate amongst experts in astronomy worldwide on what constitutes a planet or not; it was officially reclassified as a "dwarf planet."
Characteristics and Composition
Despite being reclassified as a dwarf planet ,Pluto continues to be an object worthy of study due to its unique characteristics .It is incredibly small compared to other planets - roughly two-thirds smaller than Earth's moon! It also has an unusual orbit that takes it closer to - then further from -the Sun than any other known object in our solar system.Pluto is composed mainly by ice made up from methane,nitrogen which gives Pluto its characteristic blue colour and Carbon Monoxide.Pluto has a thin atmosphere composed mainly of nitrogen gas.
New Horizons Mission
The New Horizons spacecraft was launched in 2006 with the primary aim of studying Pluto up close. It took nine years to reach its destination and flew by the dwarf planet in July 2015, taking detailed measurements and photographs. The mission revealed many surprising details about this distant world, including evidence of active geology on its surface, with possible cryovolcanoes - mountains which spew out icy material instead of molten lava.
Implications for Our Understanding of the Solar System
The discovery and subsequent study of Pluto have had significant implications for our understanding of the solar system as a whole. It has led to new insights into how planets form, how they evolve over time, and how they interact with their surroundings. For example, studies have shown that there may be thousands or even millions more TNOs beyond Neptune waiting to be discovered , which could radically alter our understanding about our solar system's composition.
Searching for the Ninth Planet
The Curious Case of the Missing Planet
Although Pluto was once considered to be the ninth planet in our solar system, its reclassification as a dwarf planet left astronomers wondering whether there might be another "true" ninth planet lurking out there. There were several lines of evidence that suggested such a planet might exist, including strange orbits of TNOs and other objects beyond Neptune.
Theoretical Predictions
In 2016, two Caltech astronomers - Mike Brown and Konstantin Batygin - published a paper outlining their theoretical predictions for this hypothetical ninth planet. They calculated that it would be about ten times more massive than Earth and would orbit far beyond Neptune in an elliptical path lasting around 15,000 years.
Evidence Mounts
Since then, evidence has continued to mount in support of the existence of this elusive "Planet Nine." Observations have shown that some TNOs appear to have clustered orbits, which could be explained by the gravitational influence of a massive object like Planet Nine. Other objects seem to have been tilted or twisted out of their original plane by an external force which many believe is caused by the yet-to-be-seen Planet Nine.
Challenges in Finding Planet Nine
Despite all this evidence pointing towards its existence ,the search for Planet Nine has proven difficult due to its extreme distance from Earth- currently estimated at over 700 AU (astronomical units) away from us! To put that into perspective ,our Sun-Earth distance is only one astronomical unit.There are also challenges associated with distinguishing between small distant planets like Planet Nine and other background objects such as stars or galaxies .
New Technologies
However,new technologies are being developed every day designed specifically to help locate these elusive planets .For example,the Vera Rubin Observatory will start operating soon;it will use advanced telescopes capable of scanning huge swathes of sky over time. This capability should enable astronomers to detect objects with small or irregular orbits, which could be candidates for Planet Nine.
The Controversial Naming of Pluto
The Discovery of the Ninth Planet
When Clyde Tombaugh discovered Pluto in 1930, it was hailed as a major discovery in astronomy. However, there was one small problem - what to call this new object? The task of naming Pluto fell to a young girl named Venetia Burney who suggested the name "Pluto," after the Roman god of the underworld.
Criticisms Against Naming It After A Mythical God
Although many people liked the name Pluto, others were less enthusiastic. Some astronomers felt that naming a planet after a mythical god was inappropriate and went against scientific convention. They argued that planets should be named after real people or places with historical significance.
Other Suggestions for Naming it
There were other suggestions for naming this new object, including "Minerva" (after the Roman goddess of wisdom), "Cronus" (after the Greek god who overthrew his father Uranus) and "Lowell" (after Percival Lowell, founder of Lowell Observatory where Tombaugh worked). However none gained traction like 'Pluto'.
New Horizons Mission Brings up Issue Again
The issue of Pluto's name came up again in 2015 when NASA's New Horizons spacecraft flew by this dwarf planet to take detailed measurements and photographs .Some argued that since it wasn't technically considered a planet anymore ,it shouldn't have been called by its original name .However ,others countered that regardless,it had become part our culture and history .
International Astronomical Union Involvement
In 2006,the International Astronomical Union(IAU) officially reclassified Pluto as a 'dwarf planet'.This decision sparked controversy among some astronomers around world which spilled over to include discussions about renaming it too.However,the IAU decided not to rename it but rather classify any new objects discovered beyond Neptune using more specific terms such as 'Trans-Neptunian Objects'(TNOs).
The Current Understanding of Pluto's Mysteries
The Geology of Pluto
Thanks to the New Horizons mission, we now have a much better understanding of the surface and geology of Pluto than ever before. Scientists were surprised to find that this distant world is far from being a dead, frozen ball of ice. Instead, they discovered evidence of active geology and even cryovolcanism - the eruption of icy material from beneath the surface.
The Heart-Shaped Feature
One of the most striking features on Pluto is its heart-shaped region known as Tombaugh Regio - named after its discoverer .This feature measures about 1,000 miles across and is thought to be relatively young in geological terms (less than 100 million years old). It has been suggested that it may have formed as a result of convection currents in Pluto's interior or through impact events.
Mountains on Pluto
Another surprising discovery made by New Horizons was mountains on Pluto! These peaks can be up to 11,000 feet high and are thought to be composed mainly of water ice with some rocky material mixed in. One theory suggests that they may have been created by tectonic activity caused by thermal expansion within the planet's interior.
Atmosphere Composition
Pluto also has an atmosphere , although it is incredibly thin compared to Earth's .It consists mainly nitrogen gas but also contains small amounts carbon monoxide which gives it its blue colour .The atmosphere appears to be escaping rapidly into space due to low escape velocity .
Other Discoveries
New Horizons revealed several other mysteries about this enigmatic object beyond what we've mentioned so far ,including:
- Evidence for a subsurface ocean beneath its icy crust
- Complex terrain consisting primarily outflows from glaciers
- Evidence for organic molecules such as methanol
- Its moon Charon having similar features including Cryovolcanoes
All these discoveries have opened up new avenues for research and exploration of the outer solar system beyond Pluto.
The Kuiper Belt
The discovery of Pluto led to an increased interest in studying the outer reaches of our solar system. One such area is the Kuiper Belt - a vast region beyond Neptune filled with icy objects, including dwarf planets like Pluto. This belt is estimated to contain over 100,000 objects larger than 100 km across!
Studying Objects Beyond Pluto
Studying objects beyond Pluto has been challenging due to their great distance from Earth and small size relative to other celestial bodies .However ,advancements in technology have allowed scientists to probe deeper into this region than ever before .
The New Horizons Mission
the New Horizons mission was launched by NASA in 2006 with the goal of exploring this distant region of space. It took almost a decade for the spacecraft to reach its destination - culminating in a historic flyby of Pluto on July 14th,2015.
Other Missions
Other missions are also being planned or are already underway that will allow us to further explore and study this fascinating area beyond our own planet including:
- Lucy: A mission planned for launch in October 2021 that will visit several asteroids within Jupiter's orbit
- Europa Clipper: A mission set for launch by NASA around 2024 designed specifically study one of Jupiter's moons,Europa
- Dragonfly: A drone helicopter-like craft scheduled for launch around 2027 ,to explore Titan,Saturn's largest moon.
Discoveries Made So Far
Thanks largely due to New Horizons, we now know much more about these distant worlds .Some examples include:
- Evidence for cryovolcanism on Charon (Pluto's largest moon)
- The existence nitrogen geysers on Triton (Neptune's largest moon)
- Possible subsurface ocean beneath Enceladus (one Saturn’s moons)
These discoveries have led to new questions and hypotheses about how these outer objects formed and evolved over time.
The Search for Planet Nine
The search for a ninth planet in our solar system has been ongoing since 2016 when Caltech astronomers Mike Brown and Konstantin Batygin published a paper outlining their theoretical predictions. They proposed that there must be another massive object out there, far beyond Neptune, exerting its gravitational influence on other objects in the outer solar system.
Evidence Supporting Its Existence
Since then, evidence has continued to mount in support of the existence of this elusive "Planet Nine." Observations have shown that some TNOs (Trans-Neptunian Objects) appear to have clustered orbits which could be explained by the gravitational influence of a massive object like Planet Nine. Other objects seem to have been tilted or twisted out of their original plane by an external force which many believe is caused by this yet-to-be-seen planet.
Theoretical Properties
According to theoretical calculations, Planet Nine would be about ten times more massive than Earth and would orbit far beyond Neptune in an elliptical path lasting around 15,000 years. It is thought that it may also be responsible for some other strange phenomena observed within the Kuiper Belt such as its unusual alignment with respect to other planets .
Challenges in Finding It
Despite all this evidence pointing towards its existence ,the search for Planet Nine has proven difficult due to its extreme distance from Earth - currently estimated at over 700 AU away from us! To put that into perspective ,our Sun-Earth distance is only one astronomical unit.There are also challenges associated with distinguishing between small distant planets like Planet Nine and other background objects such as stars or galaxies .
New Technologies Being Developed
Naming the Ninth Planet
When Clyde Tombaugh discovered Pluto in 1930, it was hailed as a major discovery in astronomy. However, there was one small problem - what to call this new object? The task of naming Pluto fell to an eleven-year-old girl named Venetia Burney who suggested the name "Pluto," after the Roman god of the underworld.
Support for Its Name
Despite these criticisms, support for its name continued to grow .Many people felt that Pluto's mysterious and distant nature made it fitting to have an equally enigmatic and mysterious name .As such,it became entrenched in popular culture as well.
Relevance Today
The controversy surrounding Pluto's naming still has relevance today ,especially with its reclassification as a 'dwarf planet' by International Astronomical Union(IAU) in 2006 which sparked discussions about renaming it too .However ,the IAU decided not to rename it but rather classify any new objects discovered beyond Neptune using more specific terms such as 'Trans-Neptunian Objects'(TNOs). Nonetheless,the debate around how we should approach planetary nomenclature is still ongoing .
Implications for Understanding Science and Society
The controversy around naming Pluto has significant implications not just for science but also society itself. It raises questions about how we approach scientific discoveries and their cultural significance .How do we balance scientific accuracy with cultural and historical relevance? What is the role of popular culture in shaping our understanding of scientific discoveries? These are important questions that continue to be debated within both the scientific community and society at large.
Pluto's Surface Features
Thanks to the New Horizons mission, we now have a much better understanding of what Pluto looks like up close. Its surface is covered in a variety of features, including:
- Mountains: Some peaks are as tall as 11,000 feet!
- Plains: Large flat areas that have been dubbed "Sputnik Planum"
- Craters: Indicating impacts from other celestial bodies over time
- Canyons: Including one that stretches for over 600 miles!
Composition and Atmosphere
The composition and atmosphere of Pluto are also much better understood than before.
Composition
It is believed to be composed primarily of rock and ice, with small amounts of methane and nitrogen. However ,we still don't know for sure whether it has a rocky core or not.
Atmosphere
Pluto has an extremely thin atmosphere consisting mainly of nitrogen gas with traces amounts methane .New Horizons data shows that the atmosphere can extend up to several hundred kilometers above the surface .
The Origins of Its Features
One major mystery surrounding Pluto concerns how its unique features - such as its mountains and canyons - formed. There are several theories about this, but none have been definitively proven yet. Some possibilities include:
- Tectonic activity caused by internal heat generated by radioactive decay
- Glaciers slowly flowing across the surface
- Convection in the subsurface ocean (if it exists)
Charon
Charon is one of five known moons orbiting around Pluto;it is also the largest .Recent studies suggest that Charon may once have had an underground ocean ,which raises questions about possible habitability in this moon too .Charon has some interesting features itself such as :
Chasms
Chasms on Charon look similar to those found on Earth’s Grand Canyon but they're larger and deeper .
Dark Red Patches
Charon has large, dark red patches on its surface which scientists believe to be tholins -complex organic compounds formed by the irradiation of nitrogen and methane.
Studying Pluto and its moons has significant implications for our understanding of the solar system as a whole. For example, it can help us understand more about how planets form, what conditions are necessary to support life ,and also how geological processes work in other celestial bodies which could enable us to explore other worlds beyond ours.## FAQs
When was Pluto discovered and by whom?
Pluto was discovered on February 18, 1930, by American astronomer Clyde W. Tombaugh. He was working at the Lowell Observatory in Flagstaff, Arizona when he made the discovery using photographic plates.
Why was Pluto demoted from being a planet in 2006?
In 2006, the International Astronomical Union (IAU) redefined the criteria for what constitutes as a planet. This new definition required a celestial body to meet three criteria: orbit the sun, have sufficient mass to form a spherical shape, and have cleared its orbit of other debris. Pluto was found to not meet the third criteria as it shared its orbit with other objects in the Kuiper Belt, thus it was reclassified as a "dwarf planet".
What is the current understanding of Pluto's composition?
From the data collected by NASA's New Horizons spacecraft, it has been found that Pluto has a rocky core and a mantle of water ice. Its atmosphere is primarily composed of nitrogen with traces of methane and carbon dioxide. Additionally, the surface is covered in nitrogen ice, methane ice, and traces of carbon monoxide.
Are there any missions planned to explore more of Pluto?
Currently, there are no planned missions to explore Pluto further. However, there are ongoing discussions to potentially send a spacecraft to explore further out in the Kuiper Belt to study objects similar to Pluto.