Transcript of Space
Space By Matthew White and Benjamin Tan The moon orbits around our earth as we orbit around the sun. The orbital period of the Moon is 27 days 7 hours and 43.1 minutes. To us it looks like a tiny circle in the sky, but it is really 3476 kilometers in diameter, and is (about) 382,500 kilometers away from us. Although we have been on the moon, we are still fairly unclear about what it is made out of. Like the Earth, the Moon is divided into three layers, the crust, the mantle and the core. The crust of the Moon is mostly made up of anorthositic rocks, studies reveal that Moon's mantle is much more richer in iron content, while scientists believe that the core of the Moon is made up of metallic iron with traces of nickel and/or sulfur. The moon although similar in the fact that it has a crust, mantle, and a core, it is completely different in the fact that on the moon, there is no life on the moon and no trees or water. It is litered with craters from passing meteors and has on more than one ocassion saved us from impact from one. Scientists have divided our solar system into the inner and outer planets, the inner planets are Venus, Mercury, Earth, and Mars. The outer planets are Jupiter, Saturn, Uranus, and Neptune. The outer planets, for the most part, have not ever been explored outside of a telescope. And are a total mystery when it comes to the question of whether or not life lives on the gigantic planets. Jupiter, is the largest planet in our solar system, and not just by a little bit, it is 2.5 times larger than every planet put together, or 317 times the mass of earth. Like the earth, jupiter has moons, only earth has one, while jupiter has 63. Jupiter also has a ring around it composed of dust particles kicked up as meteoroids smash into Jupiter's four small inner moons Metis, Adrastea, Thebe, and Amalthea. Most of these particles are microscopic size. Jupiter is about 778,330,000 km away from the sun and has a total mass of 1.9 x 10 to the power of 27 kg. The differences between earth and Jupiter are quite big, for instance, Jupiters atmosphere is about 90% hydrogen and 10% helium. Although not much is known about what is underneath Jupiters vast amount of storms and clouds, it is barren, without life. Saturn is the 6th planet from the sun and the second largest in our solar system. Much of what we know about Saturn is thanks to the space probe the Voyager. Saturn is surrounded by hundreds of rings, made up of pieces of ice, rocks and dust. The planet does not have a solid surface. It is made up of very light gases (hydrogen and helium). Like Jupiter, Saturn has a small core of rock and ice. It is difficult to study the surface of Saturn because it has such a thick atmosphere of swirling clouds caused by strong winds. Wind speeds can reach 1,800 km per hour (1,100 m per hr), much faster than the winds on Jupiter. The swirling spots on this photo are storms on the planet. The largest moon of Saturn is the Titan and it is the second-largest moon in the solar system. Titan is larger than the planet Mercury. It was only in recent years it was known, Saturn has 60 moons but only 52 of them have been named officially. The equatorial diameter of Saturn is 120,536 km; that’s about 9.5 times bigger than the diameter of the Earth. The surface area of Saturn is 83 times the area of Earth, and the volume is 764 times the volume of Earth. In other words, you could fit 764 planets the size of Earth inside Saturn. Finally, the mass of Saturn is 95 times the mass of the Earth. There is also no life on Saturn. Uranus' atmosphere is about 83% hydrogen, 15% helium and 2% methane. There are also traces of water and ammonia. The planet's atmospheric details are very difficult to see in visible light. The methane gas above the cloud layers gives it a blue-green colour. Uranus is the only planet in our Solar System to spin on its side. The axis of rotation tilt is 98 degrees. The severe tilt to its rotational axis may have resulted from a great collision long ago. Uranus is a 'Gas Giant' with no solid surface. It may have a small, silicate-rich core, but most of its gas consists of water, ammonia and methane. Its surface area is about 8,115,600,000 km2 . More than 80 percent of the mass of Uranus is contained in an extended liquid core consisting primarily of 'icy' materials (water, methane and ammonia) with higher-density material at depth. If you know where to look, it can occasionally be spotted with the naked eye, however, it can be hard to see due to the similarity of the background stars. The only spacecraft to visit Planet Uranus was the Voyager 2 spacecraft in a flyby in 1986. It discovered 10 moons and two rings in addition to studying moons and rings previously seen from Earth. The Planet Uranus has many moons. Five of largest are Miranda, Titania, Oberon, Umbriel, Ariel. The largest moon is Titania with a radius of only 788.9 km (less than half that of our Moon). The Titania and Oberon were discovered by William Herschel in 1787. Ariel and Umbriel were discovered by William Lassell in 1851. John Herschel (William Herschel's son) gave the four then known moons their names in 1852. In 1948 Gerard Kuiper discovered the moon Miranda. There is no life on Uranus. Uranus is over 4 times larger than Earth in diameter, in mass over 14 times bigger, and volume over 63 times bigger than Earth. Neptune is the eighth planet from the Sun and the fourth largest planet in the solar system. It is 4.5 billion km (2.8 billion miles) from the Sun. Neptune was visited in 1989 by a spacecraft called Voyager 2. Much of what we know about Neptune comes from this mission. Neptune is one of the gas giants (along with Uranus, Saturn and Jupiter). Its atmosphere is mostly hydrogen and helium gases. Methane gas in the upper atmosphere gives Neptune a beautiful blue color. High white clouds streak the blue atmosphere. Neptune is similar to Uranus. The two planets are also called ice giants. It has a solid core approximately the size of Earth. The core is surrounded by water and other melted ices. Neptune completes a rotation in 16 hours. It takes nearly 165 Earth years for Neptune to orbit the Sun. The dwarf planet Pluto's orbit sometimes crosses Neptune's orbit. From 1979 to 1999 Neptune was actually farther from the Sun than Pluto was. Now Pluto is the farthest from the Sun. Even though Neptune is so far from the Sun and a very very cold planet, there appears to be seasonal changes. Since the planet takes almost 165 years to orbit the Sun, a single season may last more than 40 years. Like the rest of the planets, (except earth) in our solar system, Neptune has no life. Neptune is 3.9 times bigger than earth. The mass of Neptune is 1.02 x 1026 kg. If you wanted to write it out, it would be 102,000,000,000,000,000,000,000,000 kg. Neptune has 17 times as much mass compared to the Earth. The volume of Neptune is 6.3 x 1013 km3. You could fit 57 Earths inside Neptune and still have room to spare. Pluto was once considered the 9th planet in our solar system, but in 2006 astronomers dismissed it as being a comet, or a moon because of how small it is. Since it is so far away, little is known about Pluto, however what we can guess is that Pluto has an estimated diameter less than one-fifth that of Earth or only about two-thirds as wide as Earth's moon. The planets’ surface conditions probably consist of a rocky core surrounded by a mantle of water ice, with more exotic ices such as methane and nitrogen frost coating its surface. Pluto's orbit is highly eccentric, or far from circular, which means its distance from the sun can vary considerably and at times, Pluto’s orbit will take within the orbit of the planet Neptune. When Pluto is closer to the sun, its surface ices thaw and temporarily form a thin atmosphere, mostly of nitrogen, with some methane. Pluto's low gravity, which is a little more than one-twentieth that of Earth's, causes this atmosphere to extend much higher in altitude than Earth's. When traveling farther away from the Sun, most of Pluto's atmosphere is thought to freeze and all but disappear. In the time that it does have an atmosphere, Pluto can apparently experience strong winds. Our Sun is much closer to us than any other star. Light from the Sun takes about eight minutes to reach Earth, but the light from the next nearest star takes a several years to reach us. Stars are distant Suns, but so far away they look like points of light. They are giant balls of hot gas, just like our Sun. They are also like people. They are born, live through a long middle age, and finally die. Some stars are alone, like our Sun, and others have a constant companion, usually another star. Stars also change as they age. These changes take place over millions and billions of years so we don't notice them. Stars are born out of huge clouds of gas and dust that fill some of the space between the stars. As it enters its "middle-age" it shines steadily, powered by the hydrogen fusion in is center. All stars, no matter how large they are, eventually run out of hydrogen "fuel" at their centers, and begin to die. Our Sun is now about halfway through its middle age. It will continue to give us light and heat for another 5 billion years. How long a star lasts depends on how big it is. The biggest stars live fast (meaning hot) and die young by blowing themselves to bits (Supernova) . Smaller stars live calmly for hundreds of millions of years and die much more quietly. Stars all seem to be made up of the same elements that are found on Earth, even though they can be different sizes, temperatures, and ages. Our Sun is an average-size star, maybe a little smaller than most stars. Stars the size of our Sun are known as Dwarf Stars. The largest stars can be 10 times larger across then the Sun. These are called Giant or SuperGiant stars. The very smallest stars are not much bigger than the planet Jupiter. They can all be different colors. Their color depends on their temperature, how hot they are. The coolest stars are nearly 500 degrees, while the hottest stars can reach 90,000 degrees. Cool stars appear red, and hot stars look bluish-white. Although when we look up into the night sky, the distance stars seem to twinkle, they actually do not, it is just our earths atmosphere distorting the light as it gets to us, making it look like the starts are glistening and twinkling Constellations are groups of stars that seem to be in a pattern from where we stand on Earth, however these stars are not as close as thought by many. They can actually be lightyears apart. The constellations we see light up the night sky. Some, such as the big dipper, have many stories behind them from many different cultures, some cultures made up these stories to scare children into listening to their parents. While others were made to try and understand how they were formed. An example of one of these stories is from a First Nations tribe, that said the big dipper was made when a bunch of kids didnt listen to their parents and didnt stop dancing, even without food, they eventually got so light from lack of food, that they floated up into the night sky, one looked back down at the ground and fell, becoming a shooting star, while the others formed the big dipper. Now this is of corse a myth and was made to scare the children into listening to what their parents / elders told them. However the big dipper and all the other constellations were most likely formed from the big bang, and we just viewed them as different shapes in our night sky. The constellations, (and the rest of the stars) appear to move around the night sky. This is due to our rotation on our axis and around the sun, which is why they appear to spin around us. Galaxies are large systems of stars and interstellar matter, typically containing several million to some trillion stars, of masses between several million and several trillion times that of our Sun, of an extension of a few thousands to several 100,000s light years, typically separated by millions of light years distance. They come in a variety of flavors: Spiral, lenticular, elliptical and irregular. Besides simple stars, they typically contain various types of star clusters and nebulae.We live in a giant spiral galaxy, the Milky Way Galaxy, of 100,000 light years diameter and a mass of roughly a trillion solar masses; our Sun is one of several 100 billions of stars of the Milky Way. The nearest dwarf galaxies, satellites of the Milky Way, are only a few 100,000 light years distant (and closer in case of some dwarfs which are currently merged with the Milky Way), while the nearest giant neighbor, the Andromeda Galaxy (M31), also a spiral, is about 2-3 million light years distant.Full transcript
Spiral galaxies usually consist of two major components: A flat, large disk which often contains a lot of interstellar matter (visible sometimes as reddish diffuse emission nebulae, or as dark dust clouds) and young (open) star clusters and associations, which have emerged from them (recognizable from the blueish light of their hottest, short-living, most massive stars), often arranged in conspicuous and striking spiral patterns and/or bar structures, and an ellipsoidally formed bulge component, consisting of an old stellar population without interstellar matter, and often associated with globular clusters. The young stars in the disk are classified as stellar population I, the old bulge stars as population II. The luminosity and mass relation of these components seem to vary in a wide range, giving rise to a classification scheme. The pattern structures in the disk are most probably transient phenomena only, caused by gravitational interaction with neighboring galaxies.Our sun is one of several 100 billion stars in a spiral galaxy, the Milky Way.
These are, in short, "spiral galaxies without spiral structure", i.e. smooth disk galaxies, where stellar formation has stopped long ago, because the interstellar matter was used up. Therefore, they consist of old population II stars only, or at least chiefly. From their appearance and stellar contents, they can often hardly be distinguished from ellipticals observationally.
Elliptical galaxies are actually of ellipsoidal shape, and it is now quite safe from observation that they are usually triaxial (cosmic footballs, as Paul Murdin, David Allen, and David Malin put it). They have little or no global angular momentum, i.e. do not rotate as a whole (of course, the stars still orbit the centers of these galaxies, but the orbits are statistically oriented so that only little net orbital angular momentum sums up). Normally, elliptical galaxies contain very little or no interstellar matter, and consist of old population II stars only: They appear like luminous bulges of spirals, without a disk component.However, for some ellipticals, small disk components have been discovered, so that they may be representatives of one end of a common scheme of galaxy forms which includes the disk galaxies.
Often due to distortion by the gravitation of their intergalactic neighbors, these galaxies do not fit well into the scheme of disks and ellipsoids, but exhibit peculiar shapes. A subclass of distorted disks is however frequently occuring. Mercury is the closest planet to the Sun in our solar system. It is grey in colour and its volume is only about 4.5% of Earth's. Mercury's atmosphere is quite thin so which means in cannot keep the planet on a very stable tempature. In the day the tempature can go up to 430° C, while in the night as low as -187° C. Only half of the planet is hot while the other half that isn't facing the Sun is cold! Mercury is quite like Earth, the planet is made of heavy elements. Mercury is made up of around 70% metal and 30% rock. Mercury is the second most dense planet in our solar system! Astronomers have figured out that Mercury's diameter is 4879 kilometers along its equator. This planet is smaller then the biggest moon in our solar system, Titan and Ganymede! Its volume is only 5.4% of Earth's volume. Its gravity is pretty weak to ours too! It is only 38% of our gravity so if you weighed 100 pounds here, then you only way 38 pounds on Mercury! Venus is like the Earth's evil twin. It has similar mass, surface area, and orbit but the moment you step your foot on the planet, it would kill you instantly! The atmospheric pressure on Venus is so intense on Venus that you would be crushed! It is 92 times stronger then Earth's. Venus is pretty much dead. Very harsh climates. It is the hottest planet in our solar system. Its atmosphere is made up of 96.5% carbon dioxide. You would not be able to breathe on this planet! As it is a twin, Venus's core, like Earth's is made of metal. The mantle is liquid and the crust is solid rock. At first, we didn't know what Venus was composed because of the clouds surrounding the planet. Before we had a robot venture its land, people thought Venus was a planet that was lush like a rain forest! How wrong were we? Venus Earth is the planet that we live on. It is about 4.6 billion years old and is still going strong! Our average life span is about 67 years so one person couldn't have lived on this planet would of have seen this planet from the beggining. It was formed through the proccess called accretion. We have one moon, and its called the moon! If you could take our planet and sort it out into its elements, you’d have the following: 32% iron, 30% oxygen, 15% silicon, 14% magnesium, 3% sulfur, 2% nickel, and then smaller piles of calcium, aluminum, and other trace elements. The crust is on top, that's where we live. This varies in depth between 5 and 75 km. It is mostly made of silicates, with a large amount of oxygen mixed in. Actually 47% of the Earth’s crust is oxygen! 70% of the Earth's surface would be water! Did you know Earth is the only planet in our solar system that has life? Well it's true! There aren't any aliens...for now. Earth One of the most amazing phenomena in space is a nebula. A nebula is an interstellar cloud that is composed of dust, hydrogen and helium gas, and plasma. It is created when parts of the interstellar medium collapse and clump together due to the gravitational attraction of the particles that consist of them. To the average observer they look like a collasal, colored blob floating in space. There are too many nebulae to be counted. Nebulae show if its the beginning or the end of a star. Meteors are also known as shooting stars and falling stars. Meteors come from comet debris. It won't be visible to it hits our atmosphere where it burns up and makes a great light show! If the meteor actually survives the fall through the Earth's atmosphere and reaches our surface it is then called a meotorite! Sometimes during the year a whole group of meteors will come to earth and create a spectacle called a meteor shower. It is quite unlikely you to see a meteor unless you look at the sky everyday. Comets are rarely seen to the naked eye. A comet is a small, irregularly- shaped, icy body that circles the Sun in big, elliptical orbits, which come quite close to the Sun, and then go back into space, sometimes way past our universe. A comet is made up of a solid nucleus or core, enclosed in a cloudy atmosphere called coma. Together, the two make a comet’s head, while one or two tails develop as the comet comes nearer to the Sun.When the comet approaches the Sun, the nucleus icy material slowly evaporates, and the melted ice becomes into the coma of gas and dust. The coma grows larger the closer it gets to the Sun, even becoming a larger size then the planets. Radiation from the sun and solar winds push dust particles away from the coma, forming the comet’s dust tail. While a comet’s nucleus only measures from a few hundred meters to tens of kilometers across, some comas have been known to reach diameters of up to 1 million miles or 1.6 million kilometers. Also, comet tails can extend to distances of more than 100 million kilometers.
Comet What is an asteroid? Asteroids are any of numerous small planetary bodies that revolve around the sun. They are also called planetoids or minor planets. Most Asteroids in our solar system are in the "Asteroid belt," in between the orbit of Mars and Jupiter. An asteroid can be from any size, from a dust particle up to the largest one, Ceres, which is 933 km in diameter and is considered to be a planetoid or minor planet. Some asteroids even have their own moon or travel in pairs! The main difference between an asteroid and a meteor would be that asteroids have a fixed orbit while meteors do not. Also the main difference between a comet and an asteroid would be that comet's are made up of icy material while asteroids are composed of rocky and metallic materials. Asteroids form near the sun so thats why there is not ice while comets come from further away from the sun. The End! Mars is the furthest inner planet away from the sun. Mars orbits the sun at an average of 228 million kilometers. The diameter of Mars is 6,792 km across. This is about half the diameter of Earth. The mass of Mars is even lower; the planet has a mass of 6.42 x 1023 kg, which gives it a mass of only 10% compared to Earth. The composition of Mars, is quite the same to the Earth. The surface is mostly volcanic, with vast plains of basaltic rock – this gives Mars its red color. Known as the “Red Planet“, Mars appears as a red world in telescopes, and even from the surface of the planet. Unlike Earth, it’s a dry world without moisture and almost no atmosphere. The atmosphere of Mars has only 1% the pressure of Earth’s atmosphere. Mars has two irregular, asteroid-like moons: Phobos and Deimos. Phobos (approximately 22 km across) orbits Mars at a distance of around 9,377 km.