The Universe

Pluto is the second smallest dwarf planet in the Solar System. Pluto was originally classified as a major planet but as the years passed, Pluto was then considered as one of the largest members of the distinct dwarf planets called the Kuiper Belt. The Kuiper Belt is the home of the distinct and small planets. This belt is composed basically of metal and rocks and it is composed largely of ammonia, methane and water. Pluto is no longer considered a member of the planets in our Solar System.

But first, we must know how Pluto has been discovered, right? It started during the mid 1900’s at the Lowell Observatory located in Flagstaff, Arizona. When several observations were found where they monitored, there was another planet that is disturbing the orbit of Uranus. Then after a thorough study and research, they concluded that there is another planet around Uranus and Neptune. Pluto was named first as “Planet X” by the observers. Also, around the world many people suggested names such as Minerva, Hades, Cronus and Pluto. On May 1, 1930, Pluto was voted as the top choice of the people which came from an eleven-year old girl named Venetia Burney from Oxford, England. The mass and size of the Pluto is 0.66 percent of Earth’s size, which initially made it as one of the smallest planet on the orbit. Pluto’s atmosphere is composed of a thin cover of methane, carbon monoxide and nitrogen that is derived from the ice of the planet’s surfaces. Pluto’s orbit is remarkably different compared to the other planets because it is highly inclined and has eccentric orbit. Pluto has three known moons. One of them is Charon, a moon that astronomers called as the double planet of Pluto because it has relatively the same size and same face as Pluto. The other two moons of Pluto are Hydra and Nix. There are three possible structures of Pluto such as the first layer, which is the frozen nitrogen; the second layer is water ice and the third layer is composed of silicate and water ice.

Several researches and studies have been made by the astronomers and they recommended to re-classifying the status of Pluto as only a minor planet not a major planet for the reason that it is so small and it fails to have dominant gravitational influences. This is why they opted to classify this planet as a dwarf planet and group it into the Kuiper Belt. There are several debates and controversies, which ignited the re-classifying of Pluto as not included in the group of the nine major planets in our solar system. Some suggested that it should not be re-classified because for the past 75 years, Pluto was well-known all over the world as the ninth planet and it was hard to change what has been written on the text books and science histories. Venetia Burney-Phair who is already 89 years old had been interviewed months after re-classifying Pluto as only a minor planet. She thinks Pluto should remain as a member of the major planets.

Each day in earth begins at midnight. Different countries have their midnight starting at different intervals depending on their location on the Earth’s globe. The day occurs when the sun lights up the sky. This usually starts at around 6:00 in the morning. The night takes place when the sky is dark and only bright tiny spots and the moon are seen. The night usually starts at around 6:00 in the afternoon and ends to the same cycle the next day.

Midnight happens when a certain part of the Earth is directly opposite the sun and noon occurs when that part directly faces it. The changing of the sky from day to night is due to the Earth’s continuous spinning on its imaginary axis. While the Earth revolves around the sun, it is also rotating and spinning, like a ball being turned on top of a finger while the person carrying the ball moves around another person. Every time it completes a turn, a day is finished. It takes 24 hours for the earth to complete a rotation on its axis. This means that at any time, one half of the earth sees the sun while another is directly the opposite. This also means that different parts of the Earth such as countries and continents experience different parts of day and night in different times. That’s why there are different time zones. While a family in Athens eats their breakfast at 7:00 in the morning, a person that lives in Kiritimati eats his dinner at 7:00 in the evening at the same time.

Every time a certain part of the earth is facing the darkness or opposite the sun, it may or may not see the moon. The moon also orbits around the earth just like how the earth revolves around the sun; the moon doesn’t spin on its position though. It takes 27.3 days for the moon to completely go around the earth and this is the reason why the moon doesn’t look the same every night on the same part of the world. This is why every month, there are times when only quarter, half or the wholeness of the moon can be seen at different intervals. The moon’s revolution around the earth doesn’t mean that every month, it will be directly in between the sun and the earth, forming a direct line. This was calculated to only happen every 18 years, 11 days and 8 hours, causing a solar eclipse. A solar eclipse, which only happens when the moon is between the sun and the earth and when the three forms a perfect line, doesn’t happen every month. This is because the moon’s orbit is inclined at 5 degrees with respect to the Earth’s orbit around the sun. It does not orbit in parallel with the Earth’s orbit.

Even when the earth spins, the movement of the planet is not at all noticed by humans. It is because the planet is so massive and its strong gravitational force keeps everything on the ground just like a great, powerful and spherical magnet.

There are 8 major planets in the solar system and they have a few things in common. In the order of increasing distance from the sun, these planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn and Neptune. They all directly orbit the Sun and they have mass that don’t go below 38% of Earth’s mass.

All these 8 planets are believed to have formed 4.6 billion years ago, in a big explosion, which is called ‘the big bang’. There are several other theories that assume the creation of the solar system or of the whole universe. It is believed that the solar system started as a giant swirling cloud of dust and gas. This cloud, also called the ‘Solar Nebula’ moved rapidly and the denser particles accumulated in its center. The core became the sun. The rest of the cloud continued to revolve around the sun and solid rocky particles in the cloud bumped and joined together. They formed planetisimals, which later came together and formed these spherical bodies that we now call planets.

Thus, the planets also started as clouds of gas, dust and rocky particles spinning rapidly just like the solar nebula. The denser materials clumped together, forming the core. The lighter materials steered into the surface. The gravitational draw that comes from the core causes the cloud of dust to compress towards the center. This is the reason why all planets are perfect globes. Every planet has a core, which could consist of molten rock or solid and cold materials. Outside the core, is an outer layer or mantle. The Earth’s mantle continuously moves around the core and it acts like a big dynamo that produces magnetic force towards the center of the Earth. Then, there is the outer covering which is called the crust. For the Earth, the crust is rocky and solid.

The planets are divided into two groups. The 4 innermost planets, namely Mercury, Venus, Earth and Mars are the terrestrial or Earth-like planets. From the word terra which means Earth, these planets have solid, rocky crusts that envelope their fluid mantle. These planets have magnetic chemicals such as nickel and iron.

The second group is called the Jovian planets. It means Jupiter-like. These planets are the ice giants, Neptune and Uranus; and the gas giants, Jupiter and Saturn. It is believed that their position from the sun, being the outermost planets in the solar system, has affected their geological composition. Unlike the terrestrial planets, the Jovian planets have no solid crusts. Instead, gases such as hydrogen and helium are abundant in their crusts and these light elements diffuse into their atmospheres. They all have rocky cores. The gas giants have a mantle made of metallic hydrogen while the ice giants have mantles that consist of ammonia, water, methane and different kinds of ice.

Pluto, which was originally thought to be a planet, is now considered a dwarf or minor planet. It is after scientists learned that other objects that have almost the same mass as Pluto also revolve around the sun near Pluto’s orbit.

Plutarch, a Greek philosopher who lived around A.D. 100, believed that there are people on the moon. It was also thought that it is Earth’s nearest neighbor in space and that it also has seas and lands. These are assumptions that were made before humans were able to scientifically study the moon.

There is no life of any sort on the moon. Even the smallest living organism would have not survived in the moon’s environment. Although man has touched its soil, the astronauts who visited the moon still had to wear special gears so they can breathe and walk on it. The moon’s crust was found to be geochemically unique and its composition may be a result of fractional crystallization of an ocean of magma, which the moon could be made of when it was first formed. The elements known to be present in the surface of the moon are oxygen, iron, magnesium, silicon, aluminum and calcium. Its atmosphere have been found to have potassium sodium, radon, polonium, helium, argon, oxygen, methane, carbon monoxide, nitrogen and carbon dioxide.

It must first be known how life is maintained in all living organisms. Each living thing is made of cells – the building blocks of life. These microscopic units are also made of parts, which are responsible for the continuous processes that undergo inside a cell. A cell needs to take in substances that are necessary for its survival. It gets its energy from substances such as sugar, oxygen, protein, sunlight and water. There are different kinds of life on earth and some of these organisms can live with minimal resources and even in extreme conditions and temperature. But all living things have one thing in common – they all need water. Even the smallest living thing needs water.

The moon has no body of water. Small amounts of it may have been deposited on the surface of the moon during meteoroid and comet impacts. Even if this is true, sunlight might have broken down the water into its basic elements – hydrogen and water. Moreover, any amount of water on the surface of the moon could have floated far into space because of the moon’s weak gravity.

Although the moon’s atmosphere has some oxygen in it, it is inadequate for the moon’s atmosphere or what’s also called the ‘lunar atmosphere’ to be habitable. This so-called atmosphere can more appropriately be called an exosphere. An exosphere consists of elements that come from the outer surroundings of the planet. It consists primarily of hydrogen and helium.

There is no intelligent life or any kind of life on the moon. Even a single-celled organism will not be able to live in it. There is no scientific theory that may still be being worked on that speculates the probable existence of life on the moon. The moon is considered to be planet-like due its structure but its resources are far from sufficient to support life.

On earth, during a cloudless night, while sunlight does not outshine the stars, 2,000 to 3,000 stars can be seen by the naked eye. They crowd the night sky and it is impossible to count them without using any tool. The number of stars that people see every night change as the Earth revolves around the sun. Since the Earth is a sphere, people on the northern hemisphere do not see the same stars that people who live in the southern hemisphere do. When seen from Earth the stars appear to twinkle or the light around them appears to dance. This is because of the Earth’s atmosphere and not because starlight really sparkles. Up close, stars are extremely huge and glowing balls of compressed hydrogen and helium. The sun, which is the only star that exists inside the solar system, doesn’t glitter like how the stars do, because of its proximity to Earth.

Billions of light years away, an impossible to count number of stars surrounds the earth and the solar system. They come in different sizes and colors. Their sizes range from 20 kilometers to .9 billion kilometers. They are believed to have been part of the universe since 10 billion years ago or possibly around the age of the universe. New stars may still be born and those that exist now still continue to evolve and change over time. Outside the solar system are approximately 100 billions of stars that are clustered and held together by their gravity inside the milky way, which is the galaxy where the solar system is located.

A star is believed to form inside a galaxy from a molecular cloud, which consists mainly of hydrogen, about 25% helium and some denser elements. The explosion or collision triggers gravitational instability inside the clouds and as this continues, the cloud will reach the minimum density that is needed for the formation to start collapsing under its own gravitational force. As it collapses, the gravitational power is then converted into heat and this gives the formation an extremely high temperature. When it reaches equilibrium or hydrostatic balance, a protostar will form in the middle and this is often enclosed by a protoplanetary disk. This is just the beginning, the star will continue to evolve in several million years and will eventually die out or collapse.

When the universe was first formed, around 13 billion years ago, it is believed that the universe expanded from a hot and dense state and resulted to the formation of galaxies. Each galaxy is possibly made up of millions of clusters of different types of stars. Each galaxy may be compared to a sack full of peas. The whole universe is believed to be 93 billion light years wide and this means that there is an unbelievably large space to fill up. Inside the observable universe, it is assumed that billions of galaxies exist. This means billions of trillions of stars. The universe is like a football field with the earth as a microscopic dust. And there may be more of it outside of the already huge space that humans can presently observe.

Mars has no rings. Using comparative analysis, it should not have one since it has a solid structure just like the Earth. The only planets in the solar system known to possess rings are Jupiter, Saturn, Uranus and Neptune. All are considered the outer and giant planets. Unlike Mars, their main compositions include ice and gas.

That reasoning may be correct – but just for now. Mars may possibly become one of the ringed planets after several million years. The length of time is not exact but it is a prediction based from scientific observations that may come true. The reason behind this lies in the principle of how planets acquire rings of cosmic dust. One proposed way that a ring around a planet can be formed is when a smaller body such as an asteroid collides with a satellite of the planet. This will cause disrupted fragments from the collision to fling out into space. As the planets’ strong gravitational force draws the particles, it will eventually reach the Roche limit. The Roche limit, which calculations were first defined by French astronomer Edouard Roche, is the distance or boundary within which a celestial body will disintegrate when another body, which has a stronger gravity, exceeds its own. Plainly speaking, if a meteor reaches the roche limit of a planet, it will disintegrate and disperse around an imaginary arc or circle. This imaginary circle is where the ring forms. Collisions, which happen near the planet or caused by its satellites will cause rubbles of dust to diffuse around and in a distance from the planet. The roche limit breaks down the debris into finer particles, and then forms a ring.

Even with this in mind, it may still be a question how Mars’s moon may cause collisions that are big enough to form rings. Phobos and Deimos, which are Mars’ only satellites are irregularly-shaped, small in size compared to other moons, and can be compared to asteroids. They may crash into other smaller bodies but the debris from the collision may still not be enough to form a ring.

However, Phobos, which name is the Greek word for Fear, is believed to be set for doom. It is described to be orbiting in a death spiral around Mars. Instead of orbiting in a fixed path, it is observed to be drawing closer to Mars by 1.8 cm every year. Phobos, which is thought to be an asteroid that possibly came from the asteroid belt that surrounds Mars orbit, may eventually crash into Mars after several million years. Another possibility is that it not may not really touch Mars surface. Instead, it may reach the Roche limit and fall to microscopic dust particles that will orbit Mars and form a ring.

A ring around the red planet sounds interesting and more theories about the composition of the ring may be further developed. It is intriguing to think of how it will look like, what color it will be, or if it will be as spectacular as the rings of Saturn. The answers can only be known if the Mars ring theory will come true – and if Earth and its inhabitants will continue to exist until that time.

Jupiter has a system of rings, which consists of 3 major components. Also called the Jovian ring system, the rings of Jupiter are not as visible from the Earth as those of Saturn. The rings are extremely faint and are made mostly of dust. Having low albedo, the rings don’t reflect enough sunlight so it can be easily seen. Voyager 1, the first spacecraft sent in the attempt to learn if the rings exist, took the first photograph of the rings but the image was not clear enough. Voyager 2 flew to take more images and had to be positioned under the shadow of Jupiter while it faces the sun to get more defined shots of the rings. The images confirmed 3 rings. The Galileo spacecraft also explored the Jovian ring system and studies are still being conducted from Earth.

The innermost ring, called the Halo, was reported to be discovered in 1998. The discovery was new, although the rings of Jupiter were not the first rings revealed in the solar system. The Halo ring is torus or doughnut-shaped and contains unbelievably small particles, which are 100 times smaller than a unit of sand. Interestingly, it moves in the opposite direction of Jupiter’s rotation. It is 12,500 kilometers thick and 30,500 wide.

The outer edge of halo eventually merges into the inner edge of the second ring, which is called the Main ring. It is the brightest among all the Jovian rings. It is 7000 kilometers wide and quite thin. Both the Main ring and Halo are thought to have resulted from the dust coming from the small moons Adrastea and Metis, which orbits are contained inside the two inner rings. The Galileo spacecraft confirmed the details of the Main ring, which were only speculated using the images taken by Voyager.

The third part of the ring system consists of a pair of identical and fairly uniform rings. They are called the Gossamer rings. They cover the orbits of the moons Amalthea and Thebe. They are very broad and extraordinarily faint. The outermost part of the pair is the widest among all the Jovian rings at 97,000 kilometers. The images of the Gossamer rings taken during past explorations show that they are also made up of atomic particles. It was only during the Galileo spacecraft exploration that a clear image of the Gossamer rings was produced. Since the Gossamer rings are extremely diffused and thin, the image still had to be overexposed to make it well defined.

The dust particles that build up the ring system are believed to exist and stay in the rings for 100 to 1000 years. As some particles fall out of the system or get pulled by Jupiter’s magnetic field, the ring system gets replacement. Considering that Jupiter is a tremendously gigantic ball of magnet, passing micrometeors and other bodies constantly get attracted to its gravitational field and they eventually collide with the 4 inner moons that are bigger bodies that orbit around Jupiter. The collisions hurl out big amounts of dust, which afterwards deposit into the collection of dust in the rings.

The moon is the brightest object in the Earth’s night sky. It is what gives off light on the other side of the Earth that doesn’t face the Sun. It doesn’t have internal heat and just radiates the light that comes from the Sun. It is also the only celestial object, aside from the Earth, that human beings had set foot on.

The formation of the moon, according to the ‘Big Whack’ theory, was caused by the collision of the Earth with a planet-sized object. During the crash, a small part of the Earth in the form of a cloud of dust particles disengaged from the Earth and started to orbit around it. The cloud then turned into several rocks and then gathered together forming the moon. The rapid motion of these bodies caused extreme heat and turned the conjoined parts into one ball of magma, which cooled down and solidified.

Almost everything about the moon, the Earth’s sole satellite, has been learned and almost every human adult knows what the moon looks like, from afar and up close. It is well known that the surface of the Moon is not smooth. From the Earth and without using a telescope, a human should be able to see light and dark areas on the moon’s surface. The light areas are rocky, cratered and uneven high grounds, which are called ‘Terrae’. Terrae is the Latin word for lands. These highlands are part of the crust of the moon and can be compared to the solid part of the Earth. The earth’s land area has changed over the years, resulting to mountains, valleys or canyons. The Earth’s weather and the movement of the Earth’s molten mantle, which lies underneath the crust, brought these changes.

The Terrae of the moon, has also changed over billions of years, but the transformation was not caused by its internal composition. The craters on the moon’s surface were caused by impacts made by asteroids, comets and meteoroids. After the moon was formed, asteroids and other objects that move in space have attacked it. There are numerous craters on the moon and many have diameters that exceed 20 miles. The largest crater on the moon is called the South Pole-Aitken Basin and it is 1,550 miles in diameter.

The dark areas on the moon are called Maria, which is the latin word for seas. It is because of the smoothness of these parts. Although they are also cratered, volcanic eruptions on the moon partly flooded these craters with lava, which eventually cooled down and turned to rock.
The craters on the moon have accumulated over billions of years. Most have been named by the International Astronomical Union.

Craters can become present on any solid astronomical body and may be caused when a significantly smaller object crash into it. Craters are known to be the major land feature of many solid objects in the solar system. These include the moon, asteroids and other small moons in the solar system. Ganymede and Callisto, which are among Jupiter’s largest moons, are also heavily cratered.

Stars, the bright, twinkling tiny spots of light that can be seen in the sky during the night, in fact have sizes that a human brain would not be able to exactly picture. These balls of light are so far from the earth that their distance is also unbelievable.

The nearest star from the earth is the Sun and it is the only star in the solar system. It is the star on which Earth, the other planets, asteroids, and other objects in the solar system revolve. When the Earth is closest to the sun, the distance is approximately 146 million kilometers, and at its farthest, it is 152 million kilometers away. Although the sun is extremely huge, having a radius (distance from its center to its surface) of 432,000 miles, almost equivalent to ten times the size of Jupiter and 100 of the Earth, it is still considered a dwarf star. It is still one of the smallest stars known to exist in the universe.

Outside the solar system are billions of trillions of stars. The nearest star to Earth, other than the sun, is Proxima Centauri. Its name came from the latin word ‘proxima’ which means ‘nearest to’. It is estimated that this red dwarf star is 4.2 light years from earth or 39.96 trillion kilometers. It means that light that would travel from the Earth will reach Proxima Centauri’s surface only after 4.2 earth years. Proxima Centauri is part of a star system, which includes Alpha Centauri A, and Alpha Centauri B. From the sun, Proxima Centauri is 25 trillion miles distant.

The solar system and the Sun is part of the Milky Way galaxy, which contains 100 billions of stars. Just like how planets revolve and exist in a system just like the solar system, the stars exist and chiefly populate a galaxy. A galaxy is the most complex and massive system known to exist in the universe. It consists of stars of different sizes and colors. Outside the Milky Way galaxy possibly exists more galaxies with billions of trillions of stars. These galaxies may be 12 billion light years away and each of them will have millions of swarms of stars clustered together because of gravity. Surprisingly, there may be several billion trillions of stars in the whole universe.

Abell 1835 IR1916 is, so far, the most distant galaxy known to exist in the universe. It was detected and observed using the Very Large Telescope, which is a set of four large, individual optical telescpes. Each telescope has a diameter of 1.8 meters and using these along with other instruments in other observatories, the French and Swiss astronomers of the European Southern Observatory was able to determine the existence of Abell 1835. Its distance from the Earth is approximately 31 billion light years. This estimation was made possible even at such a great distance using the method ‘gravitational lensing’, which includes bending light from a source (earth), around a target object (in this case the Abell 1835) and to the observer. The stars in this galaxy are so far the most distant stars known to exist.

Jupiter is the biggest planet in the solar system. It was named after the highest mythical Roman god who ruled over all the deities who live in Mt. Olympian. The name was given to the planet even before its exact mass was learned. But it was branded just right.

When it comes to size, dimension and mass, Jupiter way outranks all the other planets in the solar system. Even if all mass of the other seven planets are combined, Jupiter’s mass is still more than twice bigger and heavier. The mass or weight of Jupiter is measured to be 1.8986 x 1027 kg and is equivalent to 317.8 times the mass of Earth. Its volume or the measurement of space that it covers is 1.43128×1015 km3 or 1321.3 times that of Earth. It is 1,321.3 times wider and bigger than Earth but is less dense, that’s why it’s only 317.8 times heavier.

Its density is around 1.33 grams per cm3, which is just a little denser than water. It is equivalent to ¼ of Earth’s density. The Earth’s composition consists chiefly of metal and rock, which are both very dense. On the other hand, Jupiter is a giant ball made mainly of gas and liquid. The possibility of the existence of solid material in the planet is still unknown. Astronomers believe that it has a low density because it consists chiefly of hydrogen and helium, which are the lightest elements.

It is also believed that Jupiter’s core is made of the same heavy elements as that of the Earth’s. This has not been proven yet, but the core is thought to be rocky. The existence of it was only based on observations on Jupiter’s gravity. Outside the core is possibly a layer made of metallic hydrogen and some helium.
Jupiter’s atmosphere is made up of mostly hydrogen, some helium, and small amounts of methane, phospine, ammonia, germanium, carbon monoxide, ethane, acetylene and water. These substances have created different colored layers of clouds in varying altitudes. There are ammonia clouds, blue clouds made from different elements and water clouds. Jupiter’s size and composition is possibly the reason why it has numerous moons orbiting around it. It has 63 known moons and more may be further discovered. The global surrounding of Jupiter is just unbelievably vast that it cannot be totally encompassed by numerous flybys and spacecraft explorations that have been sent to the planet. So far, the outermost moon is known to orbit the planet at an average distance of 29.54 gigameters in 980 Jupiter days. It was discovered in March 4, 2003.

The volume, density and composition of Jupiter are believed to cause it to shrink at 2 cm per year. Its gravitational field causes the dense materials around its core to shrink and this produces heat. It’s the reason why Jupiter radiates more heat than it receives from the sun. This also means that when Jupiter was born, it could have been hotter and more massive.