All About Pluto - The Dwarf Planet

Universe is a mysterious place, which combines both space and time. And even more intriguing is science. Many years ago we discovered a Virus which created the world's first epidemic. Today, we discovered a new type of virus that caused the Pandemic. So, everyday science discovers new things which are still kept secret from us. 

 

If you see the instagram posts of NASA,  every now and then the agency posts pictures of the surface of a planet. Recently they posted a picture of stars, with a caption that said, “It’s not the years, it’s the mileage.” 

 

The NASA Hubble telescope captured a collection of galactic monuments 26000 light years from earth. So, what I am trying to say is Science changes every day.

 

Same goes for one of our solar system’s dwarf-planet, Pluto. Once we counted that there were nine planets, but now we say that there are only eight planets. Why is that? Let’s ponder upon that question and learn more about Pluto.

 

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The Dwarf Planet- Pluto

 

Clyde Tombaugh, a 24-year-old research assistant at the Lowell Observatory in Flagstaff, Arizona, was the first to spot photographic evidence of the former eighth planet. Tombaugh's ashes are now aboard the New Horizons probe, which flew by Pluto on Tuesday. 

 

Percival Lowell, an astronomer, predicted Pluto's existence 15 years before Tombaugh discovered it, even mapping its approximate position based on the irregularity of Neptune's orbit.

 

When Venetia Burney's grandpa told her about the newly found planet, she suggested naming it Pluto after the Roman god of the Underworld. It felt appropriate, because Pluto the planet, like the God, resided at the apex of the solar system. 

 

Her grandpa liked the name and proposed it to a friend, who happened to be an astrophysics researcher at Oxford University. They were really keen about the name Pluto because the first two letters were the initials of Percival Lowell’s name.

 

Pluto is a huge, distant component of the solar system that was formerly thought to be the solar system's outermost and smallest planet. It was also thought to be the most recently discovered planet, having been identified in 1930. 

 

The International Celestial Union (IAU), the scientific community's body entrusted with identifying astronomical objects, agreed in August 2006 to remove Pluto from the list of planets and reclassify it as a dwarf planet. 

 

The adjustment follows scientists' discovery that Pluto is a big member of the Kuiper belt, a collection of ice and rock debris left over from the creation of the solar system that is presently spinning around the Sun beyond Neptune's orbit.

 

How did the name of Pluto originate?

 

Pluto is named after the Roman deity of the underworld (the Greek equivalent is Hades). It is so far away that it takes more than five hours for the Sun's light, which travels at around 300,000 km (186,000 miles) per second, to reach it. 

 

Standing on Pluto's surface, an observer would view the Sun as a dazzling star in the dark sky, supplying Pluto with 1/1,600 of the amount of sunlight that reaches Earth. As a result, the surface temperature of Pluto is so low that ordinary gasses such as nitrogen and carbon monoxide exist as ices.

 

Data about Pluto

 

1. Pluto is not visible to the naked eye in the night sky. Its biggest moon, Charon, is close enough in size to Pluto that the two entities are sometimes referred to as a twin system. Pluto is represented by the symbol.

 

2. Pluto's distance and tiny size meant that even the greatest telescopes on Earth and in Earth orbit could only discern a small portion of its surface. Indeed, fundamental parameters like its radius and mass have been impossible to calculate for decades. 

 

Many major concerns concerning Pluto and its surroundings were not solved until the US spacecraft New Horizons sailed by Pluto and its satellite Charon in July 2015.

 

3. Pluto's mean distance from the Sun is around 5.9 billion kilometers (3.7 billion miles or 39.5 astronomical units), giving it a greater orbit than the outermost planet, Neptune. (One astronomical unit [AU] is the average distance between Earth and the Sun, which is approximately 150 million kilometers [93 million miles].) 

 

4. Its orbit is unusual in various aspects when compared to those of the planets. It is the most elongated, or eccentric, of the planetary orbits and the most inclined (at 17.1°) to the ecliptic, the plane of Earth's orbit, around which the orbits of the majority of the planets lie. 

 

5. Pluto is really closer to the Sun than Neptune for a tiny portion of each rotation. Despite this, the two bodies will never collide because Pluto is trapped in a stabilising 3:2 resonance with Neptune; that is, it completes two cycles around the Sun in the time it takes Neptune to complete three. 

 

The last time Pluto reached perihelion was in 1989; for roughly ten years before that, and again thereafter, Neptune was further away from the Sun than Pluto.

 

6. Pluto's brightness swings with a period of 6.3873 Earth days, which is now firmly established as its rotation period, according to observations from Earth. Pluto's physical properties are likewise unusual when compared to the planets. 

 

7. Pluto has a radius less than half that of Mercury and is around two-thirds the size of the Earth's Moon. It is remarkably small in comparison to the outer planets, which include the giants Jupiter, Saturn, Uranus, and Neptune.
    

Pluto appears to have more in common with the big frozen moons of the outer planets than with any of the planets themselves when these features are paired with what is known about its mass and chemistry.

 

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About Pluto’s Atmosphere

 

Although the discovery of methane ice on Pluto's surface in the 1970s gave scientists confidence that the world possessed an atmosphere, firsthand observation of it had to wait until the next decade. Pluto's atmosphere was discovered in 1988 when it passed in front of (occulted) a star as seen from Earth. 

 

The star's brightness diminished progressively shortly before it vanished behind Pluto, indicating the presence of a thin, significantly expanded atmosphere. Because Pluto's atmosphere should consist of steam in balance with its ices, modest temperature changes should have a huge influence on the quantity of emissions in the air.

 

Pluto's very eccentric orbit can carry it more than 49 times as distant as Earth from the sun. Pluto's distance from the sun varies greatly because its orbit is extremely eccentric, or far from round. For 20 years out of Pluto's 248-year orbit, the dwarf planet is closer to the sun than Neptune, giving scientists a unique opportunity to study this little, frigid, faraway world. 

 

When Pluto gets closer to the sun, its surface ices melt and generate a thin atmosphere composed largely of nitrogen with a trace of methane. Pluto's low gravity, which is around one-twentieth that of Earth, enables its atmosphere to stretch far higher in height than Earth's.

 

Occultation observations revealed that nitrogen was the predominant component in Pluto's atmosphere, which also contains trace quantities of methane, carbon monoxide, and hydrogen cyanide.

 

Haze layers can be detected up to 200 kilometers in height (120 miles). The upper atmosphere is relatively long, reaching 1,800 km (1,100 miles) above the surface, and quite cold, preventing nitrogen from escaping into space.

 

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Formation, Structure, Shape, and Surface of Pluto

 

It is a member of the Kuiper Belt, a collection of objects that orbit in a disc-like zone beyond Neptune's orbit. This faraway world is populated by millions of small frozen worlds that originated early in our solar system's existence, some 4.5 billion years ago. These frozen bodies are known as Kuiper Belt objects, often known as plutoids.

 

Pluto is around two-thirds the size of the Moon and is thought to have a rocky core covered by a layer of aqueous ice. Methane and nitrogen frost, two unusual ices, blanket the surface. Pluto's mass is around one-sixth that of Earth's Moon due to its lower density.

 

The surface of Pluto is made up of mountains, valleys, plains, and craters. Temperatures can range from -375 to -400 degrees Fahrenheit. Pluto's highest mountains range in height from 6,500 to 9,800 feet (2 to 3 kilometers). 

 

The mountains are massive slabs of water ice, occasionally encrusted with frozen gases such as methane. Craters as big as 162 miles (260 kilometers) in diameter dot sections of Pluto's topography, some of which exhibit indications of erosion and filling.

 

Pluto was only viewed from one hemisphere by New Horizons. Tombaugh Regio, a white heart-shaped plain, dominates that hemisphere. Sputnik Planitia, a flat plain of nitrogen ice devoid of impact craters, occupies the western part of Tombaugh Regio. 

 

The paucity of craters indicates that Sputnik Planitia is a youthful structure, implying that Pluto has some geologic activity. These mountains are presumably composed of water ice that is floating in the surrounding nitrogen ice. Darker plains characterize higher northern latitudes. 

 

The darkest area of Pluto is located to the west of Tombaugh Regio. This region, first termed "the whale" because of its form and then renamed Cthulhu Regio, features a complex terrain that includes plains, scarps, mountains, and craters.

 

Watch the video to know more about Pluto

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What is a Dwarf Planet?

 

According to the International Astronomical Union, a "dwarf planet" is a celestial body in direct orbit of the Sun that is massive enough that its shape is controlled by gravitational forces rather than mechanical forces (and thus ellipsoid in shape), but has not cleared its neighboring region of other objects.

 

As a result, the IAU's three requirements for a full-sized planet are:

 

1. First and foremost, this is in orbit of the Sun.

 

2. Second, it has enough mass to achieve hydrostatic equilibrium (an almost circular shape).

 

3. Finally, it has "cleared the neighborhood" in which it is orbiting.

 

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Why is Pluto a Dwarf Planet?

 

Pluto fits just two of these requirements and fails to meet the third. It hasn't cleared its neighborhood in all the billions of years it's been there. You may be wondering what "not cleaning its adjacent region of other items" implies. It sounds like a space minesweeper!

 

This signifies that the planet has achieved gravitational dominance – there are no other bodies of equal size in space other than its own satellites or those otherwise subject to its gravitational pull. As a result, any big body that does not fit these requirements is now classified as a "dwarf planet," including Pluto.

 

Facts about Pluto

 

1. While Pluto's icy neighbours are to blame for its solar system's demise, they are also what make the New Horizons mission so appealing.

 

2. Prior to the discovery of the Kuiper Belt, the solar system was thought to be divided into two zones: the inner zone, which included the rocky planets Mercury through Mars, and the outer zone, which contained the gas giants Jupiter through Neptune. 

 

Pluto, on the other hand, introduced scientists to our solar system's third zone, which Moore described as a "vast region of ice planets."

 

3. Charon, Styx, Nix, Kerberos, and Hydra are its five moons. Charon is the biggest, having a diameter somewhat larger than Pluto's. It is the largest known dwarf planet moon.

 

Pluto and Charon have an amorphous connection. Because the barycenters of their orbits do not fall within either body, they are regarded to have a binary system relationship.

 

4. Pluto's downgrade from planet to dwarf planet remains very contentious to this day. Even now, there are people in positions of power at NASA who strongly support Pluto's reclassification as a planet, while others continue to treat it as one regardless of the IAU's decision.

 

Back in 2015, NASA published images indicating a heart shape measuring around 1,000 kilometers broad. According to NASA, "much of the inside of the heart seems strikingly featureless–possibly a clue of ongoing geologic processes."

 

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What is there in the future for Pluto?

 

NASA's New Horizons spacecraft arrived at Pluto in 2015, but due to its incredible velocity, it raced past the dwarf planet in a couple of minutes. 

 

NASA is now considering sending another mission to Pluto, but this time it will linger in orbit to explore the surface. Because the last trip was a success, exposing a complex universe, it is only reasonable that more missions will be dispatched there.