Exploring the Solar System potx

[...]... fixed in the center of the cosmos, and all the other planets and the Sun orbit around it Ptolemy explained the wandering paths of the planets by claiming that these planets moved around in their own mini-orbits within different layers of celestial stuff Ptolemy’s theory may not sound that convincing today, but it was then If you accept the Ptolemaic system of circles and spheres as true, the system can... on the starscape from Dipper always keeps its ladle shape because it’s not the stars, one night to the next And their speed and direction change, but Earth, that is moving This changing view allows us to use The bright evening star near the Moon isn’t a star at all It’s the planet Venus they didn’t twinkle They also noted that these brightly too Sometimes they move quickly, but other times slowly— the. .. compared to the nearest star, Alpha Centauri It’s 25 trillion miles (40 trillion km) away! That’s the difference between walking a single step and hiking across the state of Indiana! These five planets are not a part of the unchanging starscape background They’re part of our solar system Everything in the solar system planets and their moons, dwarf planets, asteroids, and comets—travels around the Sun... different from the thousands of others— background of lights out in space Our view of the starscape shifts during the year as the Earth travels around the Sun The shining “stars” seemed to move differently, too On most Big Dipper, for example, appears handle up in the sky during nights, these five “wandering stars” travel from east to west the summer and handle down during the winter But the Big But they show... when it’s closer to the Sun He scope, he saw that it went through phases— also discovered that the longer it took a planet just like the Moon does This proved that Venus to orbit the Sun, the farther away it was from orbits the Sun, just like the Moon orbits the the Sun These ideas about how planets move Earth Galileo also discovered that the Moon became known as Kepler’s laws (see the Kepler wasn’t... from looking at the Sun The Pope exonerated Galileo 350 years after his death 7 8 Prehistory–1900: Spying on the Heavens wasn’t the unique center of the cosmos It was that makes the Earth orbit around the Sun? It is simply one of many worlds that orbited the Sun the same force Newton had discovered gravity Earth was in the Sun’s realm Our world belonged to a solar system Gravity is the force of attraction... the focus The eyepiece lens magnifies the image created at the focus point and brings it to the eye Refracting Telescope Reflecting telescopes, like the kind Isaac Newton built, use curved mirrors to collect the light entering the telescope Light from the Moon or a star is reflected off a large concave primary mirror at the far end of the telescope tube The curve in the mirror concentrates the reflected... to telescopes The round disk near the astronomer’s hand is a rotating plate of different light-splitting prisms 15 16 Prehistory–1900: Spying on the Heavens Spectroscopy proved what astronomers had been seeing in their telescopes—that the planets, moons, and the Sun are made of the same elements that make up the Earth Everything in the solar system is made of the same stuff Of course, the visible light... Set the tube notched side up Set the compact disc keep tilting Once you see the rainbow on the YOU’LL NEED on top of the tube so that the side of the disc that Scissors has writing or a printed label is up, facing away 7 Now use the spectroscope to observe the spectra from the tube, and the shiny (diffraction grating) of different kinds of light Hold the spectroscope side is down, facing into the under... half, then fold that half again Open left or the right of the Sun; it doesn’t matter the paper up and use a pencil or pen to draw a Place the string loop around both pushpins Use line in the longest horizontal crease the colored pencil or pen to draw an oval inside 2 The spot where the unlined crease intersects with the line you drew is the midpoint Label the the string loop, as shown This path shows . about the solar system all the time. At this moment space missions and astro- nomical observatories are further exploring the planets, moons, dwarf planets, comets, and asteroids of our solar system. . of the starscape shifts during the year as the Earth travels around the Sun. The Big Dipper, for example, appears handle up in the sky during the summer and handle down during the winter. But the. fixed in the center of the cosmos, and all the other planets and the Sun orbit around it. Ptolemy explained the wandering paths of the planets by claiming that these planets moved around in their