Untitled Document Pluto
A scientific report
By Wouter Verschoof and Steven van Driel


Contents

0.0 Introduction

1.0 The discovery of Pluto

2.0 History and Future of Pluto
2.1 History
2.2 Future

3.0 Facts about Pluto
3.1 Orbit
3.2 Temperature
3.3 Composition and atmosphere

4.0 Comparison with Triton
4.1 Orbit
4.2 Composition
4.3 Atmosphere

5.0 Excercise with Pluto

6.0 Special images

7.0 Afterword

0.0 Introduction

This report contains information about Pluto. It will tell something about the discovery, history and future of Pluto, and will also inform you of the basic characteristics of the planet.
We have used Pluto as the subject of this report because there are a lot of strange facts about Pluto and we were interested in the anwers to the questions which rise when reading these facts.
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1.0 The discovery of Pluto

In the 1840s John Couch Adams and Urbain-jean-Joseph LeVerrier made calculations which predicted the presence of Neptune. With similar calculations several astronomers predicted the presence of trans-Neptunian planet. Among them was Percival Lowell, who was believed to be able to make the right calculations. He established a special observatory for the search for the trans-Neptunian planet in 1905. He and his colleagues searched for the planet for many years. In 1916 Percival Lowell died. The project was placed in the hands of Clyde William Tombaugh.
In 1929 a special telescope was ready, which was designed by Percival and his colleagues. It was a fast wide field telescope, which was specialy made for the search for the trans-Neptunian planet. With this telescope he made photographic plates of selected sky regions, taken several days apart, looking for images of moving objects. The project was carefuly planned, so that other moving objects, such as asteroids, could be easily recognized. On 18 February 1930 Clyde discovered the trans-Neptunian planet on plates which he had taken on 21, 23 and 29 January 1930.
Of the many suggestions which were made, the name Pluto was chosen because the symbol, which represented Percival Lowell’s initials, could be used to represent the name of the planet.
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2.0 History and Future of Pluto

This chapter will handel the history and the possible futures of Pluto.
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2.1 History

The history of Pluto is uncertain. There are many theories about where the planet exactly came from. There are a few which are believable, if you look at them carefully.
The most likely one is that Pluto is a former moon of Neptune and was perturbed way by some reason. This theory is supported by the facts that Pluto very closly reassembles Triton and that its trajectory crosses Neptune’s.
Another possibility is that Pluto was originaly a asteroid in the Kuiper-belt, and was pulled into this orbit by some source.
It is also possible that Pluto is not really a planet, but the largest asteroid in the Kuiper-belt. (This differs from version two in the fact that it is still asteroid, and is still in its orginal orbit.)
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2.2 The future

Like with the history, there are many possibilities of what could happen to Pluto in the future.
The most likely one is that Pluto will, like all other planets, be destroyed when the Sun, in 109 years, will increase in size and become a red giant star.
It is also possible that a large asteroid or comet hits Pluto and pushes it out of its orbit. What happens next depents on the trajectory of the comet/asteroid. It is possible that Pluto will crash into the sun, or that Pluto will be pushed out of our solar system.
It is even possible that Pluto will be destroyed when it collides.
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3.0 Facts about Pluto

Pluto is the ninth and also the smallest planet (for now, but this can change, because of the recent discovery of a new planet) of our solar system. It is even smaller than 7 of the moons in our solar system (the Moon, Io, Europa, Ganymede, Callisto, Titan and Triton).
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3.1 Orbit

Its orbit is highly eccentric, more than any other planet. In a bird’s eye view it looks like Pluto will, after many years, collide with Neptune. But that’s not true, because of two reasons. First, Pluto orbits in an angle of 17º to the mean plane of our solar system. Second, the time it takes Pluto to rotate around the sun has an exact 3:2 resonance with Neptune, which makes a collide or even a close approach impossible.
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3.2 Temperature

It is very cold, about -235° to -210° C (38° to 63° K).
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3.3 Composition and atmosphere

The exact composition of Pluto is unknown, although its density (which is 2030 kg/m3) suggests that it consist of 70% rock and 30% water.
There is little known about the composition of the atmosphere of Pluto, but it is assumed to contains primarily of nitrogen, carbon monoxide and methane. At the point were Pluto is closest to the sun, the atmosphere exist as a gas, the rest of Pluto’s long year, the atmosphere is frozen into ice. You can see this ice if you look at Pluto (with a telescope), the darker spots are ice.
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4.0 Comparison with Triton.

We will compare Pluto with Triton, because it is very well possible that they both once were moons of Neptune, and because of the great familarity between the two.
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4.1 Orbit

A similarity between Triton’s and Pluto’s orbit is the inclination. These make a great angle with the mean plane of our solar-system. The difference between the two of them is only 2.98º. A difference between the orbits is that Triton moves round in a retrograde direction.
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4.2 Composition

The compositions of Pluto and Triton are very similar. The are both made of mostly rock, ice (water) and methane frost.
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4.3 Atmosphere

The atmospheres of Triton and Pluto are very similar as well. Both the planets have a tenuous atmosphere which consits of nitrogen, carbon monoxide and methane.
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5.0 Excercise with Pluto

a. The average distance between Pluto and the Sun is 39.53 AU, the greatest distance between them 49.26 AU. How great do you expect the shortest distance between Pluto and the Sun to be?
Answer: 49.26-39.53=9.73
39.53-9.73=29.8
The shortest distance is 29.8 AU

b. If you know that an AU = 0,1496*109 km, and that light travels at the speed of 3,0*105 km/s, how long does it take the light to reach Pluto at its shortest distance?
Answer: 29.8*0.1496*109=4458080000
4458080000/3.0*105=14860.267
14860.267/3600=4.12785
60*.12785=7.671
7.671/60=40.267
It takes the light 4 hours, 7 minutes and 40 seconds to reach Pluto at its perihilion.



c. Far in the future there will be launched a mission to Pluto (the Pluto-Express) which should arrive when Pluto is at its perihilion, the place where it is the closest to the sun. This is because the atmosphere on Pluto is at that moment unfrozen, while the rest of Pluto’s long year it is frozen into ice. The next perihilion is at January the 29th, 2274. The Pluto-Express will travel with a constant speed of 12*105 km/h. Fuel is not a problem. When should the Express leave Earth if it wants to reach Pluto at its perihilion?
Answer: 28.8*0.1496*109=4308480000
4308480000/12*105=3590.4
3590.4/24=149.6
150-(29<Jan.>+31<Dec.>+30<Nov.>+31<Okt.>)=29
30-29=1st September
The Pluto-express has to leave earth at:
September the 1st 2273
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6.0 Special images



Pluto Charon System
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7.0 Afterword

This report is based on information that was obtained from the internet, the Britannica micropædia, the Britannica macropædia and the BiNaS (a book containing information for science assigments in education).
We have done as much as possible to avoid any mistakes, but it is possible that we made some. Apologies for this.
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