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I have a test on astronomy this Wednesday. So to help myself study, I'm filling this journal entry up with information about our solar system. If you're interested, go ahead and read and if you have any questions don't hesitate to ask. I'm starting from the Sun and out.
Sun: The Sun is like... freaking massive, man. D: Brought down to size to help you understand exactly how much bigger the Sun is, if the Sun were the size of a large grapefruit Earth would be the size of the tip of a ball point pin. (No, I'm not kidding.) The Sun is made up of just about every single... well, it's made up of looooads of stuff. The Sun's entire mass makes up for 99.9% of the solar system's entire mass. Yes, that's all of the planets and space chunks we've got zooming about.
Mercury: This planet, as we all know, is the closest one to the Sun in the entire solar system. Mercury is a geologically dead planet (meaning that it has no lava, no earth quakes, zip) and it also has no atmosphere. It's the smallest planet in our solar system. (Unless you want to throw poor Pluto a friggin' bone.) Because it has no atmosphere it has no "greenhouse" effect. Basically, as I'm assuming most of you know, the greenhouse effect is due to the molecules we have in our atmosphere that keep some of the heat we receive from the Sun in. With no atmosphere on Mercury there is no greenhouse effect. Therefore, while the part of Mercury that is facing the Sun super-heats up to about 425 degrees Celsius the night side, with no atmosphere to keep all of the Sun's heat in and with the planet being geologically dead (no heat from inside of the planet, it's just rock now) its temperature will drop down to about -150 degrees Celsius. It's rotation is so slow that one night on Mercury equals to 29.3 Earth days. The total rotation for an entire night and day is 58.6 days while it takes 87.9 days for Mercury to make one full complete orbit around the Sun. Mercury has no moons.
Venus: Surprisingly, Venus is the hottest planet in our entire solar system. Why? Greenhouse effect. While Mercury has absolutely no atmosphere Venus' atmosphere is super dense. The atmosphere in Venus is so dense that if you were to walk along Venus' surface it would feel like you were 0.6 miles in the ocean. Because of this Venus has an ultra greenhouse effect. It retains tons of heat, making Venus' temperature reach 470 degrees Celsius, which equals to about 880 degrees Fahrenheit. (Mind you, it takes 325 degrees to make cookies!) This is so hot that when we sent a probe to investigate Venus' surface it only lasted for one hour until it was destroyed by the intense heat. And this probe was made of TITANIUM. I mean, shiz man. That is hot. Venus' rotation, aka one entire day, is suuuuper slow. While it takes Venus 225 to make an entire orbit around the Sun just one lousy rotation takes 243 days. Because of this, while Venus has a super-dense atmosphere, it has no wind and no rain. Any liquid on its surface is instantly evaporated and wind can only exist if the planet has a moderate rotation. So Venus experiences no erosion. However, Venus has several volcanoes that have renewed Venus' surface. Venus' entire surface is about 750 million years old, quite young compared to our Moon's surface. Even so, Venus is relatively close to Earth in size (it's radius is only 5% smaller than ours) and is often referred to as Earth's "sister" planet. Venus has no moons.
Earth: We know enough about Earth, don't we? But if you really have any questions about pretty planet, just ask me. ;D
Earth's Moon: The most accepted theory for how our moon formed is called "Giant Impactor." Basically, the thought is that when Earth was still just a giant ball of molten rock with no solid surface that a huge object, roughly the size of Mars, crashed into Earth. This sent debris flying out. This debris began to orbit Earth and formed together to create our moon. The Moon's dark spots are actually called maria. The maria were formed by massive impacts on the Moon that were so powerful that they cracked the Moon's surface, which caused lava to come out and freely flow on the Moon's surface. When the Moon still had an active core it has lava. This lava, however, was very thin and runny, almost like maple syrup. So, instead of building up and forming mountains and such, it created long, flat, smooth lakes of lava that eventually cooled to form the dark spots that we now see. The lighter parts of the Moon are called Highlands. The Highlands are very dusty and made of mountains. The Highlands are older than the maria, as they formed first; and are about 1 billion or so years older than the maria. The Moon is also in a locked rotation with Earth. Basically saying, the Moon orbits and rotates the Earth in such a way that when it completes 1 orbit around the Earth it has also completed 1 rotation. Think about it: why do we always see the same face of the Moon? This is because the Earth's gravity has pulled so heavily on the Moon that it has slowed its orbit down to the point that one side is always facing Earth. Therefore, the Moon DOES in fact rotate, it's just that it rotates in such a way that only one side faces the Earth at once and the other side never sees Earth and the Earth never sees it. This type of orbit is called a synchronous orbit.
Mars: Mars is the fourth planet from the Sun. There have been rumors about Mars actually having water on its surface. This can be seen from strange marks on Mars' surface that look like dried-up river beds and materials that can only be formed in the presence of water. Today, however, there is no water. Mars possesses two moons, both of which are too small to have any effect on Mars' surface. (Unlike our moon, which causes tides because of its gravitational pull on us.) Mars has the tallest mountain in the entire Solar System, Olympus Mons, which is 3 times bigger than our Mount Everest. (Yeah, it's huge.) Olympus Mons is a dead volcano. Mars also possesses the deepest and largest valley in our entire solar system. Lucky dog! Valles Marineris is the name of the deep valley. It's as long as the U.S.A. is wide and is four times deeper than our Grand Canyon. Fudge snaps. Mars may or may not be geologically alive. It has massive wind storms due to its CO2 polar ice caps. During certain seasons, aka winter, the polar ice caps begin to freeze and try to pull in as much CO2 as possible. This creates pole-to-pole winds. The sandstorms on Mars are so massive that they can cover up Mars' entire surface. Mars red surface is due to its iron rich crust, which has rusted.
Jupiter: Jupiter is THE largest planet in our solar system and is the start of our gas giants. Jupiter is 318 times more massive than Earth, and its Great Red Spot could fit two to three Earths inside of it. Jupiter is completely made of gas and has no solid surface. (I'm still not sure how this works, sorry. xD; ) It has the largest moon in the solar system, Ganymede; which with along three other moons are so massive that they would actually be classified as planets if they weren't orbiting Jupiter. Jupiter has very, very faint rings that can only be seen at certain angles and are so fine that they're almost impossible to spot. (We only knew they existed via the probe we sent to Jupiter.) Jupiter actually has 63 KNOWN moons. Please note the word in caps. xD Despite Jupiter being so massive it makes one rotation in TEN FREAKING HOURS. That, my friends, is fast. However it takes 29 years for it to make one full orbit around the Sun.
Saturn: Saturn is the second most massive planet in our system and is known mainly by its beautiful rings. It's 95.2 times more massive than Earth. Saturn is yet another gas giant and has no solid surface. It has 42 known moons and possesses the second largest moon in the solar system, Titan. Titan, uniquely, has its own atmosphere. This atmosphere gives it a brownish-red color. Titan's atmosphere is mostly made up of methane and ethane. This atmosphere is so dense that it will actually rain methane and ethane. I... I really don't want to take a vacation there. Saturn's rings, while they look solid, are not. Instead they are bits of debris that have gotten locked in Saturn's gravity and actually contains a few of Saturn's moons in it.
Uranus: lolololol u siad ur anus1!1!!1 Anyway, Uranus is another gas giant and lacks a solid surface. Uranus' most unique feature is the fact that it rotates on its belly. Basically saying, Uranus rotates on its belly with its poles facing the Sun. In example, if Earth were like this we'd have our entire northern hemisphere facing the Sun for half of the year while the southern hemisphere would be in darkness. This means anything below the equator. This results in Uranus having very extreme seasons. A night on Uranus would be 42 years. Talk about long. D: Uranus also has rings, which are more visible than Jupiter's. It has about two dozen known moons.
Neptune: Sad to say that I don't know much about Neptune. We haven't quite reached the gas planets so a lot of what I'm talking about with these gas giants is what I've known for a while. xD; Anyway, Neptune is another gas giant and has no solid surface. It has thin, pale rings and also has something similar to Jupiter: a giant spot. Very creatively, this new area has been named The Great Dark Spot. I just bet that you can't guess what color it is. Both the Great Red Spot and the Great Dark spot are super storms. It has several moons. Thanks to Pluto's awkward orbit Neptune spends twenty years as the planet farthest from the Sun.
Pluto and Dwarf Planets: Pluto is very tiny and is only 0.0022 the mass of Earth. It has three moons and is actually in a locked, synchronous orbit with its largest moon Charon. Basically saying, one side of Pluto is always facing Charon while only one side of Charon is facing Pluto. Pluto was known as a planet for about seventy-five years. Today, however, it has been downsized as a dwarf planet. What's a dwarf planet? A "dwarf planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, (c) has not cleared the neighborhood around its orbit, and (d) is not a satellite. We actually have three dwarf planets in our solar system, one being Pluto. Another is Eris, which is about twice as far from the Sun as Pluto is. Lastly, and the closest, is Ceres. Ceres is located inside of the asteroid belt that separates Jupiter and Mars and makes up for a third of the asteroid belt's mass.
If you have any questions, fear not to ask me~
 MythicalYoko · Tue Mar 18, 2008 @ 02:26am · 5 Comments |
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