Monday, January 14 Moon 101 By Patti Hutchison It's made of green cheese. There is a man up there looking down on you. When it's full, people turn into werewolves. These are stories about the moon you might have believed when you were young. For many years, the moon has been a source of wonder. Over the past 100 years or so, people have been able to study it more closely. Men have even walked on it. We have learned a lot about the moon. There are many moons in the solar system. But earth's moon is different. It is one of the largest in the solar system. It is farther from its planet than other moons. earth's moon is made of solid rock. Other moons are made of ice. The surface of the moon is similar to earth's surface. There are areas of mountains. There are also smooth plains. The moon is covered with craters. These were formed when material from space crashed into the surface. The moon has no plants, however. There is no atmosphere or water. Nothing can grow there. There is no erosion. Scientists believe that the moon is made up of layers, just like earth. It has a crust that varies in thickness. Below that is a mantle that is solid. The core is partially molten iron. There are many theories to explain how the moon was formed. The one most widely accepted is the impact theory. Scientists believe that there was a huge collision between Earth and another large object. This collision happened about 4.5 billion years ago. Materials from earth and the other object were sent into space. Then they gathered together to form the moon. The moon revolves around the earth. It takes a little over 27 days to make one orbit. The moon also rotates. Have you noticed, though, that the same side is always facing you? The "Man in the Moon" is always looking down on you. The moon moves in what is called synchronous rotation. It rotates in the same amount of time it takes to make one revolution around the earth. In other words, it takes the moon a little over 27 days to both spin around once and orbit the earth. The moon is not a star. It does not give off its own light. So why does it shine so brightly in the night sky? The surface of the moon reflects sunlight. The sunlit part of the moon that we can see is responsible for the moon's phases. The moon might not really affect people's behavior, but it does have an effect on the oceans' tides. The attraction of the moon's gravity creates bulges of ocean water on each side of the earth. This causes the ocean levels to rise and fall each day. The moon is the closest object to earth. People have studied it from near and far. Modern equipment such as high-tech telescopes, satellites, and computers has helped people solve many mysteries of the moon.
Monday, January 14 Moon 101 Questions 1. Name two ways earth's moon is different from other moons in the solar system. 2. Why are there no plants on the moon? 3. The moon has how many layers? A. three B. five C. four 4. How long does it take for the moon to make one orbit around the earth? A. 27 days B. 29.5 days C. one month 5. Ocean tides are influenced by: A. the moon's gravitational attraction B. reflected sunlight C. the moon's rotation 6. What is synchronous rotation?
Tuesday, January 15 Phases of the Moon By Patti Hutchison Was there a full moon last night? Some people believe that a full moon affects people's behavior. Whether that is true or not, the moon does go through phases. What causes the moon to appear differently throughout the month? You know that the moon does not give off its own light. When we see the moon shining at night, we are actually seeing a reflection of the Sun's light. The part of the moon that we see shining (lunar phase) depends on the positions of the sun, moon, and the earth. When the moon is between the earth and the sun, we can't see it. The sunlit side of the moon is facing away from us. The dark side is facing toward us. This phase is called the new moon. As the moon moves along its orbit, the amount of reflected light we see increases. This is called waxing. At first, there is a waxing crescent. The moon looks like a fingernail in the sky. We only see a slice of it. When it looks like half the moon is lighted, it is called the first quarter. Sounds confusing, doesn't it? The quarter moon doesn't refer to the shape of the moon. It is a point of time in the lunar month. There are four main phases to the lunar cycle. Four parts- four quarters. For each of these four phases, the moon has orbited one quarter of the way around the earth. This is why it is called a quarter moon when it really looks like a half moon. As the orbit continues, we begin to see more than half of the lighted side of the moon. This is called a waxing gibbous moon. As the lunar month goes on, the moon continues on its path. It comes to a position where the earth is between it and the sun. This time the sunlit side is facing us. We call it a full moon. Once the full moon is reached, we start to see less and less of the sunlit side. It looks like tiny slices are being taken off. This is called waning. When we still see more than half the moon shining, it is called a waning gibbous moon. Soon, the moon reaches its third quarter phase. Again, it looks like only half the moon is lighted. We are seeing half the sunlit side. As we begin to see less and less of the sunlit portion, the moon is becoming a waning crescent. Soon it will "disappear" once again and become a new moon. There are four lunar phases: new moon, first quarter, full moon, and last quarter. It takes the moon about 29.5 days to complete this cycle. This is called a lunar month. Ancient civilizations set their calendars by the phases of the moon. Many calendars, and even some clocks, keep track of the moon's phases yet today. Phases of the Moon Questions 1. Why can't we see the moon during the new moon phase?
Tuesday, January 15 2. As the amount of sunlight we see reflected increases, it is called: A. waning B. waxing C. last quarter 3. Name the four phases of the lunar cycle. 4. After the full moon, we see less and less of the sunlit side. This is called: A. waxing B. waning C. gibbous 5. How long is a lunar month? 6. When the moon looks like a half moon, it is in its: A. full moon phase B. new moon phase C. first or third quarter phase
Wednesday, January 16 The Sun By Patti Hutchison The sun. We couldn't live without it. All life on earth depends on the energy that comes from the sun. It controls our climate and weather. How much do you know about this giant ball of energy in the sky? The sun is really a star. It is the closest one to earth. It is about 93 million miles away. The sun is the center of our solar system. All the planets revolve around it. Although it has a diameter of about 1.3 million kilometers, the sun is only a medium star. It is known as a yellow dwarf. The sun is part of the Milky Way galaxy. Scientists believe it is just a bit older than earth, about 4.6 billion years. The Sun is made up of several layers. It has a core. Next is the radiation zone. Above that is the convection zone. The "surface" of the sun is called the photosphere. Above the surface are two layers of gas. They are called the chromosphere and the corona. There is no real surface on the sun. It is made of gas, much the same way a cloud is made of water vapor. Although a cloud looks solid against the sky, it really isn't. You can't touch it or rest on it. The sun is much the same way. It only looks solid against the sky as we view it from so far away. The core of the sun is about 15 million degrees Celsius. Here, hydrogen is formed into helium by a process known as nuclear fusion. This process creates energy. This energy is radiated into space in the forms of light and heat. The sun also gives off other kinds of waves such as UV rays and X-rays. Scientists predict that the sun will keep burning for about 4 billion years. The reactions at the core cause the sun to expand if they happen too fast. Then the reactions slow down, and the sun contracts. Again, the reactions speed up. This cycle keeps the sun at a fairly constant temperature. There are some pretty spectacular events that take place on the sun. Have you heard of sunspots? These are regions on the photosphere that are cooler than the surrounding areas. Sunspots are caused by interactions with the sun's magnetic field. Sunspots have two parts. The dark region on the inside is called the umbra. The surrounding region that is not as dark is called the penumbra. Some sunspots are very small. Others are over 50 thousand kilometers wide. They can last a few hours to a few months. Sunspots come in cycles. They occur every eleven years. Solar flares take place in the corona. They are enormous discharges of magnetic energy. Huge streams of protons and electrons are sent into space. They can interrupt communications networks on earth. Did you know that there are solar winds? They result from the expansion of gas in the corona. The ions formed by this process are thrown out into space at a speed of about 500 kilometers per second. The sun makes up almost 99 percent of the mass of our solar system. It is so large; about a million earths would fit inside it. The sun has a mass of almost 333 thousand times the Earth's. By observing sunspots, scientists have learned that the sun rotates. Sunspots appear to move across the face of the sun. This is because the sun rotates on its axis. But it rotates faster at its equator than it does at the poles. This is called differential rotation. It rotates once every 27 days at the equator. But it takes about 31 days to rotate at the poles. We could not live on the sun. But we couldn't live without the sun. It is a giant nuclear furnace that warms our
Wednesday, January 16 planet. We depend on it to rise every morning and set every night- for four billion more years, at least! The Sun Questions 1. The sun is a: A. planet B. galaxy C. star 2. How old do scientists believe the sun is? A. 27 years B. 4.6 billion years C. 93 million years 3. Name the layers of the sun. 4. Nuclear fusion on the sun changes hydrogen into: A. sunspots B. X- rays C. helium 5. What are sunspots? 6. How do we know the sun rotates?
Thursday, January 17 Is Pluto a Planet? By Patti Hutchison Caption: Size comparison of Earth and its moon to Pluto and its moon, Charon It is; it isn't. It is, but with some restrictions. No, it isn't. Yes, it is, sort of. These are the arguments about poor Pluto. Is it a planet, or isn't it? Pluto was once thought of as the smallest planet. It was also known as the coldest planet since it is the farthest from the sun. It was discovered in 1930. Since then, scientists have had trouble deciding if it really is a planet or not. In 2006, the International Astronomical Union (IAU) made some new "planetary rules." According to the new rules, a true planet must do three things. First, it must orbit the sun. Secondly, it must be big enough for gravity to make it into a round ball. And lastly, it must have cleared out its orbital neighborhood. There can't be any "junk" floating around it. Let's look at these criteria in terms of Pluto. It does follow rule number one. It orbits the sun. How about rule number two? Yes, it follows rule number two. It is a round ball. Rule number three is where Pluto gets into trouble. It's "neighborhood" is full of "junk." The Kuiper Belt is close by. This is a disc-shaped belt of icy particles. Ceres, the largest asteroid known so far, also is close to Pluto. So, just what is Pluto, anyway? The IAU defines it as a dwarf planet. This means that it meets rules one and two. But it has not cleared the neighborhood around its orbit. It is also not a satellite, which meets rule number four for a dwarf planet. No matter what it is called, Pluto is still out there. No spacecraft has yet landed on Pluto, but we do know some things about it. It was discovered by an American astronomer whose name was Clyde Tombaugh. No, it was not named for the Disney character. Pluto gets its name from the Roman god of the underworld. Pluto travels in a very elliptical orbit. From 1979 to 1999, Pluto was actually closer to the sun than Neptune. But this will not happen again for another 230 years. The closest Pluto gets to the sun is about 4.7 billion kilometers. At the farthest point in its orbit, it is about 7.4 billion kilometers from the sun. It takes Pluto 248 Earth years to make one complete orbit. Pluto also has a slow rate of rotation. Its day is equal to about six Earth days. If you're going to Pluto, you'd better take your warm jacket. The average temperature there is -215 degrees Celsius. Scientists think it is the largest object in the icy Kuiper Belt. From Pluto, the sun looks like a bright star in the sky. Pluto has no air to breathe. Because Pluto is so far away, it is hard to see, even with very powerful telescopes. Scientists are not sure what its surface looks like. They believe it is covered with frozen nitrogen, methane, and carbon dioxide. Some areas are very white like snow; others are very dark. Pluto has very weak gravity. If you weigh 100 pounds on Earth, you would only weigh eight pounds on Pluto! Pluto has four known moons. The largest one, Charon, is more than half the size of Pluto. Charon is covered with ice. The two bodies are in mutually synchronous orbit. This means that they move at the same rate. They always keep the same side facing each other. If you were to look at Charon from Pluto, it would not appear to rise or set. It would seem like it was just floating in space. The same would be true if you stood on Charon and looked at Pluto.
Thursday, January 17 In 2006, NASA launched a spacecraft to Pluto called New Horizons. It will reach Pluto in 2015. Its job is to study Pluto and the Kuiper Belt. Scientists think this mission will give us clues about how the solar system was formed. Is Pluto a Planet? Questions 1. What does IAU stand for? 2. Why is Pluto considered to be a dwarf planet? 3. A disk-shaped belt of icy particles in Pluto's orbital neighborhood is called: A. Charon B. Ceres C. the Kuiper Belt 4. Sometimes Pluto is closer to the sun than Neptune. A. true B. false 5. How many Earth years does it take Pluto to orbit the sun? A. 4.7 billion B. 248 C. 6 6. If you visited Pluto, you would weigh more there than you do on Earth. A. true B. false
Friday, January 18 The Bigger Picture - Our Solar System By Mary Perrin Caption: Picture from NASA. Earth and its moon are shown on the right side, the third planet from the sun. What do you see when you look to the sky on a very clear night? You may see tiny white specks called stars and the moon, but there is much more to see! Looking into a night sky can be like looking at a toddler's drawing. You need to have a general idea of what you are looking at before you can begin to see the smaller details. Our solar system is made up of a star and the planets that move around, or obit, that star. Our sun is a star. The sun is just like the other stars you see in the sky. The sun is the closest star to earth, making it seem so much bigger and different from the other stars in the sky. The planets orbit the sun. There are eight planets in the sky. They are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. They are listed in the order they are closest to the sun. Jupiter and Saturn are the two largest planets. There are also other smaller planets called dwarf planets. Pluto is one of them. Each planet is the only one of its kind. The sun is the center of the solar system. It is our source of light and warmth. Whether you are enjoying a sunny day or a starlit night, just remember that you are a part of something extremely big and extraordinary! Continue to learn about the solar system. There is much to see and appreciate. Each time you look into a starlit sky you will see something new and exciting. The Bigger Picture - Our Solar System Questions 1. Earth is not the closest planet to the sun, but the sun is the closest to earth. 2. The sun is a. A. star B. planet C. comet D. none of the above 3. The planets move around, or, the sun. A. shine on B. follow C. change D. orbit
Friday, January 18 4. There are only seven planets. A. False B. True 5. The two largest planets are. A. Pluto and Saturn B. Jupiter and Saturn C. Pluto and the sun D. None of the above Do you have a trick for remembering the names of the eight planets? If so, explain your trick.