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Pluto Report

SES 4U Space and Earth Science

Student

Mattias Barragan

Teacher

Simona Negulescu

Report due June 12, 2013

St. Louis Adult Learning Centre

CONTENTS

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I. DISCOVERY OF PLUTOII. MOONS

III. HISTORICAL FACTSIV. FEATURES

V. PLUTO AS A MAJOR PLANETVI. PLUTO AS THE NEW DWARF PLANET

DISCOVERY OF PLUTO

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Percival Lowell, a wealthy Bostonian who had founded the Lowell Observatory in

Flagstaff, Arizona in 1894, started an extensive project in search of a possible ninth

planet, which he termed "Planet X". By 1909, Lowell and William pickering had

suggested several possible celestial coordinates for such a planet. Lowell and his

observatory conducted his search until his death in 1916, but to no avail. Unknown

to Lowell, on March 19, 1915, surveys had captured two faint images of Pluto, but

they were not recognized for what they were.

Later on, the official discovery of Pluto is attributed to Clyde William

Tombaugh who was born on February 4, 1906. He was an American astronomer. He

found the actual dwarf planetPluto in 1930, the first object to be discovered in what

would later be identified as the Kuiper belt, Tombaugh also discovered

many asteroids; he also called for the serious scientific research ofunidentified

flying objects.

Pluto is on a highly elliptical orbit at an average separation of almost 40 A. U. from

the Sun, with an orbital period of 248 years. Since the planet was only discovered in

1930, we have observed only a portion of its orbit so far. Further, the orbit is tilted

by about 17 degrees relative to the plane of the ecliptic, much more than for anyother planet. Its equatorial radius of 1150 km is only 20% of that of the Earth, and

its mass is only 0.0025 that of the Earth. Thus, it is by far the smallest planet, either

in mass or diameter. Its period of rotation appears to be almost 6 1/2 days.

MOONS

http://en.wikipedia.org/wiki/Percival_Lowellhttp://en.wikipedia.org/wiki/Lowell_Observatoryhttp://en.wikipedia.org/wiki/Flagstaff,_Arizonahttp://en.wikipedia.org/wiki/Planet_Xhttp://en.wikipedia.org/wiki/William_Henry_Pickeringhttp://en.wikipedia.org/wiki/United_Stateshttp://en.wikipedia.org/wiki/Astronomerhttp://en.wikipedia.org/wiki/Dwarf_planethttp://en.wikipedia.org/wiki/Plutohttp://en.wikipedia.org/wiki/Kuiper_belthttp://en.wikipedia.org/wiki/Asteroidhttp://en.wikipedia.org/wiki/Unidentified_flying_objecthttp://en.wikipedia.org/wiki/Unidentified_flying_objecthttp://en.wikipedia.org/wiki/Unidentified_flying_objecthttp://en.wikipedia.org/wiki/Unidentified_flying_objecthttp://en.wikipedia.org/wiki/Asteroidhttp://en.wikipedia.org/wiki/Kuiper_belthttp://en.wikipedia.org/wiki/Plutohttp://en.wikipedia.org/wiki/Dwarf_planethttp://en.wikipedia.org/wiki/Astronomerhttp://en.wikipedia.org/wiki/United_Stateshttp://en.wikipedia.org/wiki/William_Henry_Pickeringhttp://en.wikipedia.org/wiki/Planet_Xhttp://en.wikipedia.org/wiki/Flagstaff,_Arizonahttp://en.wikipedia.org/wiki/Lowell_Observatoryhttp://en.wikipedia.org/wiki/Percival_Lowell

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The dwarf planetPluto has five known moons. In order of discovery they

are Charon, Nix, Hydra, S/2011 P 1 ("P4"), and S/2012 P 1 ("P5"). Charon, the

largest of the five moons, is mutually tidally locked with Pluto, and is massive

enough that PlutoCharon is sometimes considered a double object.

CHARON

Is the largestsatellite of the dwarf planetPluto. Charon is nearly as big as Pluto.

Some astronomers call Pluto and Charon a "double planet". Charon is also very close

to Pluto. Because Charon is so close, it goes around Pluto fast. It only takes Charon a

little more than six days to orbit Pluto.

Charon's diameter is about 1,207 kilometers just over half that of Pluto, with a

surface area of 4,580,000 square kilometers. Unlike Pluto, which is covered

with nitrogen and methane ices, the surface appears to be dominated by

less volatile water ice, and also appears to have no atmosphere. In 2007,

observations by the Gemini Observatory of patches of ammonia hydrates and water

crystals on the surface of Charon suggested the presence of active geysers. Mutual

eclipses of Pluto and Charon in the 1980s allowed astronomers to take spectra of

Pluto and then the combined spectrum of the pair. By subtracting Pluto's spectrum

from the total, astronomers were able to determine the surface composition of

Charon with the spectroscope.

NIX

http://en.wikipedia.org/wiki/Dwarf_planethttp://en.wikipedia.org/wiki/Plutohttp://en.wikipedia.org/wiki/Natural_satellitehttp://en.wikipedia.org/wiki/Charon_(moon)http://en.wikipedia.org/wiki/Nix_(moon)http://en.wikipedia.org/wiki/Hydra_(moon)http://en.wikipedia.org/wiki/S/2011_P_1http://en.wikipedia.org/wiki/S/2012_P_1http://en.wikipedia.org/wiki/Tidally_lockedhttp://en.wikipedia.org/wiki/Natural_satellitehttp://en.wikipedia.org/wiki/Dwarf_planethttp://en.wikipedia.org/wiki/Plutohttp://www.windows2universe.org/pluto/binary_planet.htmlhttp://en.wikipedia.org/wiki/Nitrogenhttp://en.wikipedia.org/wiki/Methanehttp://en.wikipedia.org/wiki/Volatileshttp://en.wikipedia.org/wiki/Gemini_Observatoryhttp://en.wikipedia.org/wiki/Gemini_Observatoryhttp://en.wikipedia.org/wiki/Volatileshttp://en.wikipedia.org/wiki/Methanehttp://en.wikipedia.org/wiki/Nitrogenhttp://www.windows2universe.org/pluto/binary_planet.htmlhttp://en.wikipedia.org/wiki/Plutohttp://en.wikipedia.org/wiki/Dwarf_planethttp://en.wikipedia.org/wiki/Natural_satellitehttp://en.wikipedia.org/wiki/Tidally_lockedhttp://en.wikipedia.org/wiki/S/2012_P_1http://en.wikipedia.org/wiki/S/2011_P_1http://en.wikipedia.org/wiki/Hydra_(moon)http://en.wikipedia.org/wiki/Nix_(moon)http://en.wikipedia.org/wiki/Charon_(moon)http://en.wikipedia.org/wiki/Natural_satellitehttp://en.wikipedia.org/wiki/Plutohttp://en.wikipedia.org/wiki/Dwarf_planet

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Nix is the second moon ofPluto. It was discovered along with Hydra in June 2005

with a previous designation of S/2005 P 2, and is to be visited along with Pluto by

the New Horizons mission in July 2015. Nix was found by the (Hubble Space

Telescope Pluto companion search team). The moon follows a circular orbit in the

same plane as Charon. Its orbital period of 24.9 days is close to a 1:4 orbital

resonance with Charon, but the timing discrepancy is 2.7%, which suggests that

there is no active resonance. A hypothesis explaining such a near-resonance is that it

originated before the outward migration of Charon following the formation of all

five known moons, and is maintained by the periodic local fluctuation of 9% in the

PlutoCharon gravitational field strength.

HYDRA

Hydra is the outermost known natural satellite of Pluto. Its early designation was

S/2005 P 1 and the discovery images were taken on May 15, 2005, and May 18,

2005. Although its size has not been directly measured, calculations based on its

brightness give it a diameter of between 61 km (if itsgeometric albedois similar to

Charon's 35%) and about 167 km (if it has a reflectivity of 4% like the

darkestKuiper beltobjects). At the time of discovery, Hydra was about 25 percent

brighter than its sister moon Nix, which led to the assumption that its diameter was

some 10 percent larger. Pre-discovery data from Hubble observations in 200203

implied that Nix was the brighter moon. However, Hubble observations in 200506,

specifically targeting the dim moons, once again showed Hydra to be a little

brighter. Hydra appears to be spectrally neutral like Charon and Nix, whereas Pluto

is reddish.

S/2011 (134340)

http://en.wikipedia.org/wiki/Plutohttp://en.wikipedia.org/wiki/Hydra_(moon)http://en.wikipedia.org/wiki/New_Horizonshttp://en.wikipedia.org/wiki/Hubble_Space_Telescopehttp://en.wikipedia.org/wiki/Hubble_Space_Telescopehttp://en.wikipedia.org/wiki/Charon_(moon)http://en.wikipedia.org/wiki/Orbital_resonancehttp://en.wikipedia.org/wiki/Orbital_resonancehttp://en.wikipedia.org/wiki/Moons_of_Plutohttp://en.wikipedia.org/wiki/Geometric_albedohttp://en.wikipedia.org/wiki/Geometric_albedohttp://en.wikipedia.org/wiki/Geometric_albedohttp://en.wikipedia.org/wiki/Kuiper_belthttp://en.wikipedia.org/wiki/Kuiper_belthttp://en.wikipedia.org/wiki/Kuiper_belthttp://en.wikipedia.org/wiki/Kuiper_belthttp://en.wikipedia.org/wiki/Geometric_albedohttp://en.wikipedia.org/wiki/Moons_of_Plutohttp://en.wikipedia.org/wiki/Orbital_resonancehttp://en.wikipedia.org/wiki/Orbital_resonancehttp://en.wikipedia.org/wiki/Charon_(moon)http://en.wikipedia.org/wiki/Hubble_Space_Telescopehttp://en.wikipedia.org/wiki/Hubble_Space_Telescopehttp://en.wikipedia.org/wiki/New_Horizonshttp://en.wikipedia.org/wiki/Hydra_(moon)http://en.wikipedia.org/wiki/Pluto

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S/2011 (134340) is a small natural satellite ofPluto whose existence was

announced on July 20, 2011. Its discovery, following the discoveries ofCharon in

1978 and Nix and Hydra in 2005, made it Pluto's fourth known moon. With an

estimated diameter of 1334 km (821 mi), S/2011 (134340) 1 is the second

smallest known moon of Pluto (after S/2012 (134340) 1, which has an estimated

diameter of 1025 km (616 mi)). This diameter range is derived from an assumed

possible geometric albedo range of 0.06 to 0.35. Like Pluto's other satellites, it is

suspected that S/2011 (134340) 1 coalesced from the debris of a massive

collision between Pluto and another Kuiper belt object, similar to the giant

impactbelieved to have created the Earth's Moon.

S/2012 (134340)

S/2012 (134340) is a small natural satellite ofPluto whose discovery was

announced on 11 July 2012. It is the fifth confirmed satellite of Pluto and was found

approximately one year after S/2011 (134340) 1 (or "P4"), Pluto's fourth

discovered satellite. The moon is estimated to have a diameter of between 10 and 25

kilometers (6 and 16 mi), and orbital period of 20.2 days. P5 is estimated to have a

diameter of between 10 and 25 kilometers (6 and 16 mi). These figures are inferred

from the apparent magnitude of the moon and by using an estimated albedo of 0.35

and 0.04 for the lower and upper bounds, respectively. Because of its small size, P5

is likely to be irregular in shape. It is thought to have formed from the debris lofted

by a collision, which would have led to losses of the more volatile ices, such as those

ofnitrogen and methane. This process is expected to have created a body consistingmainly ofwater ice.

HISTORICAL FACTS

http://en.wikipedia.org/wiki/Natural_satellitehttp://en.wikipedia.org/wiki/Plutohttp://en.wikipedia.org/wiki/Charon_(moon)http://en.wikipedia.org/wiki/Nix_(moon)http://en.wikipedia.org/wiki/Hydra_(moon)http://en.wikipedia.org/wiki/S/2012_(134340)_1http://en.wikipedia.org/wiki/Geometric_albedohttp://en.wikipedia.org/wiki/Collisional_familyhttp://en.wikipedia.org/wiki/Collisional_familyhttp://en.wikipedia.org/wiki/Kuiper_belt_objecthttp://en.wikipedia.org/wiki/Giant_impact_hypothesishttp://en.wikipedia.org/wiki/Giant_impact_hypothesishttp://en.wikipedia.org/wiki/Natural_satellitehttp://en.wikipedia.org/wiki/Plutohttp://en.wikipedia.org/wiki/S/2011_(134340)_1http://en.wikipedia.org/wiki/Apparent_magnitudehttp://en.wikipedia.org/wiki/Albedohttp://en.wikipedia.org/wiki/Volatileshttp://en.wikipedia.org/wiki/Nitrogenhttp://en.wikipedia.org/wiki/Methane_clathratehttp://en.wikipedia.org/wiki/Icehttp://en.wikipedia.org/wiki/Icehttp://en.wikipedia.org/wiki/Methane_clathratehttp://en.wikipedia.org/wiki/Nitrogenhttp://en.wikipedia.org/wiki/Volatileshttp://en.wikipedia.org/wiki/Albedohttp://en.wikipedia.org/wiki/Apparent_magnitudehttp://en.wikipedia.org/wiki/S/2011_(134340)_1http://en.wikipedia.org/wiki/Plutohttp://en.wikipedia.org/wiki/Natural_satellitehttp://en.wikipedia.org/wiki/Giant_impact_hypothesishttp://en.wikipedia.org/wiki/Giant_impact_hypothesishttp://en.wikipedia.org/wiki/Kuiper_belt_objecthttp://en.wikipedia.org/wiki/Collisional_familyhttp://en.wikipedia.org/wiki/Collisional_familyhttp://en.wikipedia.org/wiki/Geometric_albedohttp://en.wikipedia.org/wiki/S/2012_(134340)_1http://en.wikipedia.org/wiki/Hydra_(moon)http://en.wikipedia.org/wiki/Nix_(moon)http://en.wikipedia.org/wiki/Charon_(moon)http://en.wikipedia.org/wiki/Plutohttp://en.wikipedia.org/wiki/Natural_satellite

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After the discovery of Pluto, it was quickly determined that Pluto was too small to

account for the discrepancies in the orbits of the other planets. The search for Planet

X continued but nothing was found. Nor is it likely that it ever will be: the

discrepancies vanish if the mass of Neptune determined from the Voyager

2 encounter with Neptune is used. There is no Planet X. But that doesn't mean there

aren't other objects out there, only that there isn't a relatively large and close one

like Planet X was assumed to be. In fact, we now know that there are a very large

number of small objects in the Kuiper Beltbeyond the orbitofNeptune, some

roughly the same size as Pluto. Pluto has not yet been visited by a spacecraft even

the Hubble Space Telescope can resolve only the largest features on its surface (left

and above). A spacecraft called New Horizons was launched in January 2006. If all

goes well it should reach Pluto in 2015.

There has recently been considerable controversy about the classification of Pluto. It

was classified as the ninth planet shortly after its discovery and remained so for 75

years. However on August 24, 2006 the IAU decided a new definition of

"planet" which does not include Pluto. Pluto is now classified as a "dwarf planet", a

class distinct from "planet". While this may be controversial at first (and certainly

causes confusion for the name of this website) it is my hope that this ends the

essentially empty debate about Pluto's status so that we can get on with the real

science of figuring out its physical nature and history. Little is known about Pluto's

atmosphere, but it probably consists primarily of nitrogen with some carbon

monoxide and methane. It is extremely tenuous, the surface pressure being only a

few microbars. Pluto's atmosphere may exist as a gas only when Pluto is near

its perihelion; for the majority of Pluto's long year, the atmospheric gases are frozeninto ice. Near perihelion, it is likely that some of the atmosphere escapes to space

perhaps even interacting with Charon. NASA mission planners want to arrive at

Pluto while the atmosphere is still unfrozen.

FEATURES

http://nineplanets.org/hypo.html#planetxhttp://nineplanets.org/hypo.html#planetxhttp://nineplanets.org/data1.htmlhttp://nineplanets.org/spacecraft.html#Voyager2http://nineplanets.org/spacecraft.html#Voyager2http://nineplanets.org/kboc.htmlhttp://nineplanets.org/data.htmlhttp://nineplanets.org/neptune.htmlhttp://nineplanets.org/spacecraft.html#hsthttp://pluto.jhuapl.edu/http://www.iau.org/http://www.iau.org/Q_A2.415.0.htmlhttp://www.iau.org/Q_A2.415.0.htmlhttp://nineplanets.org/help.html#perihelionhttp://nineplanets.org/pluto.html#charonhttp://nineplanets.org/pluto.html#charonhttp://nineplanets.org/help.html#perihelionhttp://www.iau.org/Q_A2.415.0.htmlhttp://www.iau.org/Q_A2.415.0.htmlhttp://www.iau.org/http://pluto.jhuapl.edu/http://nineplanets.org/spacecraft.html#hsthttp://nineplanets.org/neptune.htmlhttp://nineplanets.org/data.htmlhttp://nineplanets.org/kboc.htmlhttp://nineplanets.org/spacecraft.html#Voyager2http://nineplanets.org/spacecraft.html#Voyager2http://nineplanets.org/data1.htmlhttp://nineplanets.org/hypo.html#planetxhttp://nineplanets.org/hypo.html#planetx

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Orbit: 5,913,520,000 km (39.5 AU) from the Sun

Diameter: 2274 km, this is about 1/5 the diameter of the Earth.

Mass: 1.27e22 kg, this is about 1/500th of the mass of the Earth. The gravity on

Pluto is 8% of the gravity on Earth.

Pluto is on a highly elliptical orbit at an average separation of almost 40 A. U. from

the Sun, with an orbital period of 248 years. Since the planet was only discovered in

1930, we have observed only a portion of its orbit so far. Further, the orbit is tilted

by about 17 degrees relative to the plane of the ecliptic, much more than for any

other planet. Its equatorial radius of 1150 km is only 20% of that of the Earth, and

its mass is only 0.0025 that of the Earth. Thus, it is by far the smallest planet, either

in mass or diameter. Its period of rotation appears to be almost 6 1/2 days.

Pluto is 39 times farther from than the sun than the Earth is. Pluto ranges from 2.8

to 4.6 billion miles (4.447 billion to 7.38 billion km) from the Sun. From Pluto, the

sun would look like a tiny dot in the sky. Occasionally, Neptune's orbit is actually

outside that of Pluto; this is because of Pluto's highly eccentric (non-circular) orbit.

During this time (20 years out of every 248 Earth years), Neptune is actually the

farthest planet from the Sun(and not Pluto). From January 21, 1979 until February

11, 1999, Pluto was inside the orbit of Neptune. Now and until September 2226,

Pluto is outside the orbit of Neptune. Pluto has a very eccentric orbit; that means

that its distance from the sun varies a lot during its orbit around the sun. Sometimes

it is even closer to the Sun than the planet Neptune (it was that way from January

1979 to February 11, 1999)! Pluto also rotates about its axis in the opposite

direction from most of the other planets.

http://nineplanets.org/data.htmlhttp://nineplanets.org/help.html#auhttp://nineplanets.org/sol.htmlhttp://nineplanets.org/data1.htmlhttp://nineplanets.org/data1.htmlhttp://www.enchantedlearning.com/subjects/astronomy/planets/neptune/index.shtmlhttp://www.enchantedlearning.com/subjects/astronomy/sun/http://www.enchantedlearning.com/subjects/astronomy/sun/http://www.enchantedlearning.com/subjects/astronomy/planets/neptune/index.shtmlhttp://nineplanets.org/data1.htmlhttp://nineplanets.org/data1.htmlhttp://nineplanets.org/sol.htmlhttp://nineplanets.org/help.html#auhttp://nineplanets.org/data.html

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ORBITAL INCLINATION

Pluto's orbit is tilted from the plane of the ecliptic. This angle, its orbital inclination,

is 17.15. This is a much larger inclination of those of the eight planets.

TEMPERATURE ON PLUTO

Pluto is very cold. Its temperature may range from between -396F to -378F (-

238C to -228C, or 35 K to 45 K). The average temperature is -393F (-236C = 37

K).

Pluto's composition is unknown. It is probably made up of about 70% rock and 30%

water. This is determined from density calculations; Pluto's density is about 2,000

kg/m3. There may be methane ice together with frozen nitrogen and carbon dioxide

on the cold, rocky surface.

Not much is known about Pluto's atmosphere. It is probably mostly nitrogen with a

little carbon monoxide and methane - definitely not breatheable by humans. The

atmospheric pressure is probably very low. The atmosphere forms when Pluto is

closest to the Sun and the frozen methane is vaporized by the solar heat. When it is

farther from the Sun, the methane freezes again. From Pluto, the sky would appear

black, even when the Sun (the size of a star) is up.

PLUTO AS A MAJOR PLANET

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After a year of observations, Tombaugh finally discovered an object in the right

orbit, and declared that he had discovered Planet X. Because they had discovered it,

the Lowell team were allowed to name it. They settled on Pluto, a name suggested

by an 11-year old school girl in Oxford, England (no, it wasnt named after the

Disney character, but the Roman god of the underworld).

Astronomers had been turning up larger and larger objects in the Kuiper Belt. 2005

FY9, discovered by Caltech astronomer Mike Brown and his team is only a

littlesmaller than Pluto. And there are several other Kuiper Belt objects in that same

classification.

Astronomers realized that it was only a matter of time before an object larger than

Pluto was discovered in the Kuiper Belt.

PLUTO AS A DWARF PLANET

Astronomers from the association were given the opportunity to vote on the

definition of planets. One version of the definition would have actually boosted the

number of planets to 12; Pluto was still a planet, and so were Eris and even Ceres,

which had been thought of as the largest asteroid. A different proposal kept the total

at 9, defining the planets as just the familiar ones we know without any scientific

rationale, and a third would drop the number of planets down to 8, and Pluto would

be out of the planet club. But, then what is Pluto?

In the end, astronomers voted for the controversial decision of demoting Pluto (and

Eris) down to the newly created classification of dwarf planet.

For an object to be a planet, it needs to meet these three requirements defined by

the IAU:

It needs to be in orbit around the Sun Yes, so maybe Pluto is a planet. It needs to have enough gravity to pull itself into a spherical shape Plutocheck It needs to have cleared the neighborhood of its orbit Uh oh. Heres the rule

breaker. According to this, Pluto is not a planet.

http://www.universetoday.com/13867/diameter-of-pluto/http://www.universetoday.com/13867/diameter-of-pluto/http://www.universetoday.com/13867/diameter-of-pluto/http://www.universetoday.com/13867/diameter-of-pluto/