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The Myth of the Geocentric Model
The Greeks were the pioneers in trying to scientifically explain the motion of the celestial bodies. Since the Sun rises in the east and sets in the west, a logical explanation was that the Earth was a stationary object and the Sun circulated around it every day. The idea was logical but hopelessly wrong. Someone standing on the surface of Earth and watching the sky does not sense the planet as a moving object, but rather feels like everything else outside the planet is moving. However, when the astronomers tried to explain the motion of the planets based on the geocentric theory of the universe, some discrepancies and irregularities appeared.
The most complete geocentric model was proposed by Ptolemy. He used circles to describe the motion of the planets around the Earth: each planet was supposed to move around two circles, a small and a large one.
Aristarchus proposed the theory of heliocentrism, which considers the Sun as the center of the universe. Copernicus devised a new version of the heliocentric model that placed the Earth as the third planet in distance from the Sun.
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The Rings of Saturn: Are They Disappearing?
The rings of Saturn are amazing. They are made of ice and rock, which might have resulted from comets or asteroids that were torn apart by gravitational tidal forces. I saw the rings with a telescope once, and I thought: “they are real!”. Some years later I read the headline on the Internet: “Why are Saturn's Rings Disappearing?” I could imagine what Galileo Galilee felt when he discovered this phenomenon. He probably became very disappointed. Fortunately, this is not the whole story. The truth is that even when the rings are not visible for us (on Earth), they are still around Saturn. As the planet travels in its orbit around the Sun, the rings are periodically (every 14 to 15 years) in a position that makes them gradually invisible through a small telescope on Earth. This phenomenon is called “ring plane crossing”.
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The Myth of Life on Mars
Based on current data, Mars apparently has no life and no free water on its surface. However, methane gas was detected in its atmosphere, which indicates the planet still possesses processes in a biological or geological sense that can generate the gas. If the methane is being produced by living organisms on Mars, they reside below the surface, where it may be still warm and water could exist in liquid state. Unfortunately, there is no evidence of whether our neighbor planet is inhabited or not.
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The Myth of the New Planet
The largest dwarf planet known in our Solar System was discovered by the astronomers Mike Brown (Caltech), Chad Trujillo (Gemini Observatory), and David Rabinowitz (Yale University). Its name is Eris (2003 UB313) and it is the largest object found in orbit around the Sun since 1846, when Neptune and its moon Triton were discovered. Eris is larger than Pluto and is also one of the icy bodies beyond Neptune in orbit around the Sun, a region of space known as Kuiper belt, and sometimes referred to as the final frontier. The discovery of Eris once again awoken the debate on which celestial objects can handle the title of planet.
What are the differences between Pluto and Eris? Eris is bigger than Pluto, it is located further from the Sun than Pluto and has an orbit inclination of about 44° with respect to the plane of the Solar System, while Pluto has an orbit inclination of 17°. Along with Eris, Pluto was designated as a dwarf planet in 2006.
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Myth: The Moon Has No Water
- The Moon Has More Water than the Great Lakes!
For over 4 decades the scientists had believed that the Moon was dry. However, recent research revealed a large amount of water molecules inside minerals in the Moon’s interior that could exceed the volume of water existent in the Great Lakes.
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The Myth of the Vulcanoids
Scientists are looking for small objects traveling the space between the orbit of the planet Mercury and the Sun. They are called Vulcanoids. These small asteroids, if they exist, might be composed of elements that are not found in bodies located farther from the Sun. Getting to know a little bit more about the Vulcanoids is a major step in the research about the inner Solar System.
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Ptolemaic system. Art. Encyclopædia Britannica Online. Web. 5 Oct. 2010