Sunday, March 11, 2012
The Eight Planets
The Eight Planets
“Nine planets of the Solar System” used to be known to include Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. Do you know that Pluto has a relatively smaller size compared to the rest of the planets? This is why it’s been re-categorized as a dwarf planet on 24th August 2006. Since then, it was taken out from the nine planets, leaving eight of them. Now remember, now there’s only eight planets surrounding the Sun.
Let’s hop on to a journey of discovery！
Mercury
Diameter: 4,880 km
Distance from the sun: 57,910,000 km
*nearest to the sun, smallest planet among 8 of them
According to the Roman mythology, Mercury represents the god of business, travel, and theft, which also known as Hermes, the messenger of God in the Greek mythology. Mercury has been spotted since 3000 B.C. by the Sumerians. The Greeks gave it two names, by day it is called Apollo, and by night it’s Hermes. Isn’t it fascinating?
Mercury has a thin layer of exosphere that contains hydrogen and helium atoms came from the solar wind. It has a rocky surface that provides flat land at some areas. Some are made up during a volcano’s eruption and some are probably particles from a comet. It has a small magnetic field with an intensity of 1% of Earth’s magnetic field. No natural satellites were found around Mercury. Mercury can be seen with a naked eye, but due to its distance towards the Sun, it is quite hard to notice its existence.
Venus
Diameter: 12,103.6 km
Distance from Sun: 108,200,000 km
*The second planet of Solar System. Among the planets, Venus has an orbital track closest to the shape of a circle. The sixth largest planet.
Venus (Aphrodite in Greek), is known as the Greek Goddess of love and beauty. Perhaps it was because Venus is the brightest planet among all that the people had granted it such a name.
It has an extraordinarily slow rotation, with an orbital period of 224.7 days. It reaches its maximum brightness shortly after sunset or shortly before sunrise. This is why Venus is also called as the Morning Star or the Evening Star.
There are mountains and caves on its surface. It has an atmosphere that contains mainly of carbon dioxide and sulphuric acid. Due to its thick atmosphere, we could hardly see the true appearance of Venus. These gases caused a greenhouse effect to the planet, rendering all water to evaporate as the temperature rises about 400 degrees Celsius. This is why Venus’ surface is hotter than Mercury even though it’s not as close to Sun as Mercury does.
Earth
Diameter: 12,756.3 km
Distance from Sun: 149,600,000 km
*The fifth largest planet.
Earth is the only planet not being given names from Greek or Roman mythology. The word ‘earth’ originated from Old English and Germanic language. According to the Roman mythology, goddess of Earth is known as Tellus, which means fertile land. (Gaia, Mother of All in Greek)
Earth is known as one of the planets in the 16th century, during the Copernican era. Earth is also known as the only planet in the Solar System that contains water. Do you know that the Moon is a natural satellite of the Earth?
The world map was completed during the 20th century. With the help of technology, we’re able of capturing images of the Earth from the space. These provided aid of weather forecasting. 75% of the Earth is water!
Mars
Diameter: 6,794 km
Distance from Sun: 227,940,000 km
＊7th largest planet.
It was named after the Roman god of war, Mars (Ares in Greek). It is often called as the Red Planet as the iron oxide’s given its surface a reddish appearance. The name of the third month, ‘March’ originated from Mars as well.
Men had long discovered Mars in the pre-historical era. It is said to be the best place for life (other than Earth) in the Solar System. Due to its oval shaped orbital track, the difference in the changes of temperature could reach as high as 30 degrees Celsius. This very much affected Mars’ weather. The average temperature of Mars is 55℃, -133℃ during Winter and 27℃ during Summer. Mars may appear to be smaller than Earth, but its total surface area is approximately the total surface area of Earth’s land.
There are many mountains on the surface of Mars. Some tracks on its surface pointed that there could be river that once existed. Long ago, there was clean water on the surface of Mars, and there could even probably be lakes and sea. However, this all seemed to have past for about 4 billion years!
In the beginning, Mars looks similar to Earth. Most of its carbon dioxide has been derived into carbon stones. However, Mars does not possess a carbon cycle that returns the carbon to the atmosphere that causes any greenhouse effect. Thus, even if Mars was pulled to the Earth’s position, it will still be cooler than the Earth.
Diameter: 142,984 km
Distance from Sun: 778,330,000 km
＊Fifth planet from Sun. The largest planet!
Jupiter (known as Zeus for the Greeks) is the Father of Gods and men. It is the fourth brightest object is the sky (among the Sun, Moon, and Venus).
Jupiter is primarily composed of hydrogen with a quarter of its mass being helium. Surrounding the planet is a faint planetary ring system and a powerful magnetosphere. There are at least 64 Moons surrounding the Jupiter, including the four large moons called Galilean moons that were first discovered by Galileo Galilei in 1610. The largest of these moons is known as Ganymede which has a diameter greater than that of planet Mercury.
Diameter: 120,536 km
Distance from Sun: 1,429,400,000 km
*6th planet from Sun. 2nd largest planet.
In the Roman mythology, Saturn is named after a Roman god of agriculture. According to Greek mythology, the god of agriculture is named Cronus, which happens to be the child of Uranus and Gaia. He is the father of Zeus. The name of the last day of the week, ‘Saturday’ originated from Saturn too! Isn’t is strange?
Saturn has a bright ring system that consists of nine continuous main rings and three discontinuous arcs, composed mostly of ice particles with a smaller amount of rocky debris and dust.
Saturn is 95 times more massive than Earth, but its density is just 1/8 the average density of Earth. There are 62 known moons orbiting around Saturn and only 53 of them are officially named. Titan, is Saturn’s largest moon and the second largest moon in the Solar System which is larger than the planet Mercury. It’s the only moon in the Solar System to retain a substantial atmosphere.
Saturn’s interior is probably composed of a core of iron, nickel and rock (silicon and oxygen compound).
Diameter: 51,118 km
Distance from Sun: 2,870,990,000 km
＊7th planet from Sun. 3rd largest planet in the Solar System.
Uranus is the God of the Universe in the Greek mythology. He is the father of Cronus and grandfather of Zeus.
Uranus was very first discovered William Herschel on 13th March 1781 by the use of a telescope. Though it was visible to naked eyes, but it was never considered as a planet due to its dimness and slow orbit.
Uranus has an axial tilt of 97.77 degrees, so its axis of rotation is approximately parallel with the plane of the Solar System. This gives it seasonal changes completely unlike those of the other major planets.
Uranus is similar in composition to Neptune, and both are of different chemical composition than other large gas giants like Jupiter and Saturn. Astronomers sometimes place them in a separate category known as ‘ice giants’. Uranus has 11 levels of ring systems but they appear very dimly. It has numerous moons and a few large ones known as Titania and Oberon.
Neptune
Diameter: 49,532 km
Distance from Sun: 4,504,000,000 km
＊8th planet from Sun. 4th largest planet in Solar System.
According to Roman mythology, Neptune represents the God of Sea (Poseidon in Greek).
Like Uranus, Neptune contains all sort of ‘ice’ and contains about 15% of helium and hydrogen stones. Its atmosphere is made up of helium, hydrogen, and a small amount of Methane.
Neptune has its own ring system as well. However, its ring system is fragmented and faint. It is the only planet in the Solar System that orbits in a different direction.
Postscript:
I’m sure you’re learned a lot today! Did you realize that each planet of the Solar System is uniquely different? Some has ring systems, some has a lot of moons, and some of them have caves and mountains. We might find their properties existing on Earth, but there are things they have that Earth doesn’t as well.
This shows that everyone’s different, special and precious. You’re the person no one could ever replace. We should not compare ourselves to other people, because we have our strengths and so do other people. Plus, no one’s perfect. Only then, we’re able of training ourselves and improving ourselves to be a better person! Isn’t it? Other than that, everyone of us have our very own character and personality. Only YOU can express all your potential, and this is your utmost mission!
Ikeda Sensei once said “We’re the ones to make decisions in our life. You are the leading role of this drama of life. We’re all very precious. When we stray far away from ourselves, we might not achieve happiness because we’re our own priceless treasure. There is a potential in you that could change the world. Life is for us to fully express our true personality, to blossom our unique flowers. It may not be easy in reality, but we must become a great ‘leading role’ that creates a beautiful life with action and a pure heart. Life is not for others but US to judge and value!”
Shared by,
Friendship.
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