In this chapter we will explore the wonders of Uranus, Neptune and Pluto. These planets are the three farthest planets from the sun, making them extremely cold. Uranus was discoveresdin 1690 by a man named John Flamsteed, at the time of the discovery he believed that it was a star. Neptune was discoverd in September of 1846 by Johann Gotfried Galle. Pluto was discovered in 1930, it was discovered by accident. It took so long to discover Ppluto because of its size and the distance from Earth. It was discovered by Perciva Lowell.


What Uranus is made up of:
Uranus is around 4.5 billion years old. The surface of Uranus consists of bluish-green clouds that contain tiny frozen crystals of methane. Far below the bluish-green clouds on the surface, there are probably thicker clouds that are made up of liquid water and crystals of ammonia ice. Even farther down, there might be a ocean of liquid water containing dissolved ammonia. At the very center of Uranus, scientists believe that there is a rocky core that is around the size of planet Earth, but around 63 Earths could fit in Uranus.


What Neptune is made up of:
Neptune is around 4.5 billion years old. Neptune's core is composed of a mixture of molten rock, water, liquid ammonia and methane. The outside layer is made up of a mixture of heated gases. The gases that make up the outer layer are hydrogen, helium, water, and Methane. Like Uranus, the bluish color of the outer cloud gets it color, like Uranus, from the methane. Neptune is about the size of 60 Earths.
What Pluto is made up of:
Pluto is around 4.5 billion years old. Pluto is made up of ice, snow debris, and other debris. Scientist believe that the ice is frozen nitrogen. The atmosphere is very thin and believed to be made up of mostly nitrogen gas, and a little bit of Carbon monoxide and methane. Pluto is smaller than Earth. It is so small that they decided to not call it a planet anymore! They now call it a Dwarf Planet.


How Uranus and Neptune were formed:
The formations of Uranus and Neptune were the same. When the sun was created, an orbit began around it. Some of the gas that was in the area was used to form the sun, but some of the gas drifted into space. The gas orbited around the sun along with other dust particles. The dust and gas particles ran into each other, forming clumps. Eventually the clumps got big, and became what we now call Uranus and Neptune.
How Pluto was Formed:
Scientists don't really know how Pluto was formed, but they believe that it formed like KBO's. KBO's are Kuiper belt objects, these objects are small icy objects that appear to have the same characteristics as Pluto and Triton, but on a smaller scale for the most part. The Kuiper belt was formed by rocky planetesimals that were stirred by Jupiter's gravitational pull that shot them out past Neptune's orbit where they remain today to form the Kuiper belt.


Physical Characteristics of Uranus:
Uranus has a 97.86 degree tilt of axis. Some scientists believe that the reason for the extreme tilt is because it had a collision with a planet-sized body during the early years of the solar system. Although the tilt of axis is 97.86 degrees, the magnetic field is tilted 60 degrees away from the planets axis of rotation.
The reason that Uranus is a bluish-green color is due to the methane and high-altitude photochemical smog. The smog absorbs red wavelengths from the sun which leaves behind the bluish-green tone.

images-3.jpeg This picture shows Uranus true color and its false color.

Physical Characteristics of Neptune: The Bluish color is from the methane in the clouds of Neptune's atmosphere that absorb the red wavelengths given off by the sun which leaves the bluish color behind. The dark spots that are found on Neptune are hurricane-like storms. The largest dark spot is callled the Great Dark Spot and is around the size of the Earth. The strongest winds to ever be measusres on any planet were measured on Neptune near the Great Dark Spot. Winds have been recorded to have gone up to 2,000 kilometer (1,200 miles) an hour. The voyager also found irregular shaped clouds that "scoot" around Neptune every 16 hours or so. There are also long bright clouds that are found high in Neptunes atmosphere that resemble cirrus clouds that we find on Earth.

images-7.jpegThis picture shows Neptune's Dark Spot

Physical Characteristics of Pluto:
Observations from the HST show that Pluto's moon, Charon, is bluer than Pluto itself which means that they have different surface composition and structure. Scientists believe that Pluto might have a smoothly reflecting surface and a bright area parallel to the equator of Pluto because of a detailed analysis from an HST image. They do not know if all of this is true or not and need subsequent observations to confirm that it is real.Pictures taken from NASA show that Pluto has more large-scale contrast than any planet besides Earth. Scientists think that Pluto probably shows more contrast between light and dark areas than what is shown in the picture that was taken, but the telescope blurs edges and blends together smaller features.Pluto is about half of the size of the United States.

images-9.jpeg This picture shows Pluto and Earth.


Rings and Moons of Uranus:

Uranus has 22 known moons and 11 known rings. Out of Uranus's 22 moons, the two largest moons are Titania and Oberon. Titania and Oberon were discovered by William Herschel in 1787. The first nine rings of Uranus were discovered in 1977. The rings were photographed and measured from the Voyager encounters. During this time, they also found two other rings and ringlets. It is possible that there are a lot of narrow rings or incomplete rings and ring arcs that are as small as 50 meters in width. It has been found that the individual ring particles have low reflectivity. One of the rings which is known as the epsilon, was gray.

images-13.jpegThis picture is of Uranus and its moons.

Rings and Moons of Neptune:

Neptune has 8 known moons and 4 known rings. Triton is Neptune's largest moon, and has been known the longest as well. It was found in 1846 by W. Lassell. There are 2 bigger rings on Neptune that one can clearly see. the inner rings are fainter and harder to see. Portions of Neptune's rings look twisted. Scientists believe this is because original material in the rings formed clumps that formed streaks as the material orbited around Neptune.

images-14.jpegThis picture shows Neptune and one of its Moon Triton.

Pluto's Moon's:

Pluto's moon, Charon, is about half the size of Pluto. Charon's diameter is 1,172 kilometers(728 miles) and is about 19,640 kilometers(12,200 miles) away from Pluto. Charon's density is 1.2 to 1.3 g/cm cubed which means that it does not contain much rock. Charon's albedo ranges from 0.36 to 0.39 while Pluto's albedo is 0.49 to 0.66 which means it is much brighter than Charon. Pluto does not have any rings.

images-15.jpegThis is Pluto and its moon Charon.


Of Uranus:
Uranus travles around the sun in an Elliptical orbit, which means Uranus orbits in an oval pattern. Uranus's average distance from the sun is 2,872,460,000 kilometers (1,784,860,000 miles). It takes uranus 30,685 Earth days, or a little over 84 Earth years to complete an orbit. While orbiting the sun, Uranus spins on its axis; it takes Uranus 17 hours and 14 minutes to complete a rotation.
Of Neptune:
Neptune travels around the sun in an Elliptical Orbit, which means Neptune takes an oval-shaped pattern around the sun. Neptunes average distance from the sun is 4,495,060,00 kilometers (2,793,100,00 miles). It takes Neptune 165 Earth years to complete an orbit. While orbiting, Neptune spins on its axis, which is called rotation. It takes Neptune around 16 hours and 10 min to complete one rotation.
Of Pluto:
Pluto travels around the sun in an Elliptical orbit. It takes Pluto 249 Earth years to complete one orbit. While orbiting the sun, Pluto rotates synchronously with the orbit of its moon Charon. This means that the planet faces Charon continuously as it travels in space. It takes Pluto to 6 days to complete one rotation with Charon. Pluto is the farthest "planet" away from the sun. It's average distance away from the sun is 5,869,660,000 kilometers (3,647,240,000 miles), but every 20 years out of its 249 year orbit, Pluto crosses Neptunes orbit an becomes closer to the sun then Neptune.


On Uranus, Neptune and Pluto, there is no possibility of Life. The conditions on these planets are too harsh for any organisms to live on. The temperature on these planets are extremely cold. The average temperature on Uranus is -214 degrees Celsius (-353 degrees Fahrenheit), on Neptune the average temperature is -225 degrees Celsius ( -373 degrees Fahrenheit), and on Pluto the average temperature is -238 degrees Celsius (-396 degrees Fahrenheit). These conditions are too cold for anything to be able to live with.


Twin Voyagers:
Voyager 1 was launched in 1977. Its mission was to explore Saturn, Jupiter, Uranus, and Neptune. Voyager 1 completed it's close flybys of Jupiter and Saturn in 1989. Voyager 1 found that on one of Jupiter's moons', there might be an ocean of liquid water. Voyager 2 also had close flybys of Jupiter and Saturn, but it managed to complete close flybys of the two remaining gas giants, Uranus and Neptune. The VIM is an extension of the Voyagers mission that was completed in 1989. The Voyagers had been in flight for over 12 years at the start of the VIM after Voyager 2 had been launched in August and Voyager 1 had been launched in September of 1977. By July 2003, Voyager 1 was 13.3 billion kilometers away from the Sun and Voyager 2 was 10.6 billion kilometers away from the Sun.
images-12.jpeg images-11.jpegThese photos are of The Voyagers.


New Horizens:
NASA launched New Horizons in 2006, and will reach its destination of Pluto in 2015. This is NASA's first mission to Pluto and beyond. New Horizons will be speeding towards Pluto at the fast speed of 31,000 miles per hour! At this speed, on could reach the Earths moon in 9 hours, it took our astronauts 3 days to reach the moon. While the spacecraft rockets through space,it will be in hibernation mode to help conserve its energy. Once it reaches its destination, it will take the spacecraft more than 4 hours to transmit any information back to our planet, Earth. It will be transmitting information and images back to Earth for about 6 months.

PlutoNewHorizonsJHUAPLSwRI.jpg This photo is of The New Horizons Spacecraft.


In conclusion, we are still looking for more information on these planets. They are so far away from Earth, that it makes it hard to study them. As time goes by and our technology grows, we hope we will be able to obtain more information. Thank you.

Uranus NASA-
Nine Planets Pluto -
Neptune solar view-
Neptune NASA-Nasa Neptune Link