motion of the planets for many centuries, most people believed that the earth was the center of the...
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MOTION OF THE PLANETS
• For many centuries, most people believed that the Earth was the center of the universe. In this geocentric model, the Sun, the planets and the stars revolved around the Earth.
MOTION OF THE PLANETS
• For many centuries, most people believed that the Earth was the center of the universe. In this geocentric model, the Sun, the planets and the stars revolved around the Earth.
• The problem with the geocentric model is that it didn’t explain why planets sometimes changed direction and moved backwards across the sky. This backwards motion of planets is known as retrograde motion.
MOTION OF THE PLANETS
• In the 1500s, Nikolas Copernicus studied the motion of the planets and questioned whether the geocentric model was accurate.
MOTION OF THE PLANETS
• In the 1500s, Nikolas Copernicus studied the motion of the planets and questioned whether the geocentric model was accurate.
• He determined that retrograde motion happened because the planets passed each other as they orbited the Sun.
MOTION OF THE PLANETS
• In the 1500s, Nikolas Copernicus studied the motion of the planets and questioned whether the geocentric model was accurate.
• He determined that retrograde motion happened because the planets passed each other as they orbited the Sun.
• Copernicus proposed the heliocentric model, that the planets, including Earth, orbit the Sun.
MOTION OF THE PLANETS
• After the discovery of the telescope, astronomers were able to accurately measure the movement of the planets.
• In the 1600s, Johannes Kepler analyzed the observations of the planets and came up with three laws to describe the motions of the planets.
KEPLER’S LAWS OF PLANETARY MOTION
• KEPLER’S FIRST LAW: The orbits of the planets are ellipses or ovals, not circles.
KEPLER’S LAWS OF PLANETARY MOTION
• KEPLER’S FIRST LAW: The orbits of the planets are ellipses or ovals, not circles.
• KEPLER’S SECOND LAW: The closer a planet is to the Sun in its orbit, the faster it moves.
KEPLER’S LAWS OF PLANETARY MOTION
• KEPLER’S FIRST LAW: The orbits of the planets are ellipses or ovals, not circles.
• KEPLER’S SECOND LAW: The closer a planet is to the Sun in its orbit, the faster it moves.
• KEPLER’S THIRD LAW: When a planet’s orbit is larger, it moves much slower and takes a lot longer to orbit the Sun.
NEWTON’S LAW OFUNIVERSAL GRAVITATION
• Although Kepler could describe the motion of the planets, he could not explain why they moved they way they did.
NEWTON’S LAW OFUNIVERSAL GRAVITATION
• Although Kepler could describe the motion of the planets, he could not explain why they moved they way they did.
• Isaac Newton determined that the force of gravity held planets in their orbits.
NEWTON’S LAW OFUNIVERSAL GRAVITATION
• Although Kepler could describe the motion of the planets, he could not explain why they moved they way they did.
• Isaac Newton determined that the force of gravity held planets in their orbits.
• LAW OF UNIVERSAL GRAVITATION: Gravitational attraction depends on mass and distance. More mass means more gravitational attraction. More distance means less gravitational attraction.
TERRESTRIAL PLANETS• The four inner planets with solid, rocky
surfaces. In order from closest to the Sun: Mercury, Venus, Earth and Mars.
MERCURY• Closest planet, no moons.
• Orbit – 88 days.
• Rotates slowly – 1408 hours or 59 days. Three rotations for every two orbits.
MERCURY• Closest planet, no moons.
• Orbit – 88 days.
• Rotates slowly – 1408 hours or 59 days. Three rotations for every two orbits.
• Thin atmosphere of oxygen and sodium.
• Daytime temp.: 427º C or 800º F
• Nighttime temp.: - 173º C or -280º F
MERCURY• Closest planet, no moons.
• Orbit – 88 days.
• Rotates slowly – 1408 hours or 59 days. Three rotations for every two orbits.
• Thin atmosphere of oxygen and sodium.
• Daytime temp.: 427º C or 800º F
• Nighttime temp.: -183º C or -298º F
• Large iron core creates magnetic field.
• Looks like the Moon.
VENUS• Second planet, no moons. Closest planet to
Earth.
• Brightest star in the sky. Known as the Evening Star and Morning Star.
VENUS• Second planet, no moons. Closest planet to
Earth.
• Brightest star in the sky. Known as the Evening Star and Morning Star.
• Orbit – 224 days.
• Rotates backwards and slowly – 243 days.
VENUS• Second planet, no moons. Closest planet to
Earth.
• Brightest star in the sky. Known as the Evening Star and Morning Star.
• Orbit – 224 days.
• Rotates backwards and slowly – 243 days.
• Thick atmosphere of carbon dioxide – 92 times the atmospheric pressure on Earth.
• Surface temp.: 460º C or 860º F.
• Very weak magnetic field, but has volcanoes.
MARS• Fourth planet
• Two moons – Phobos and Deimos.
MARS• Fourth planet
• Two moons – Phobos and Deimos.
• Orbit – 687 days.
• Rotates every 25 hours. Has seasons.
MARS• Fourth planet
• Two moons – Phobos and Deimos.
• Orbit – 687 days.
• Rotates every 25 hours. Has seasons.
• Thin atmosphere of carbon dioxide
• Surface temp.: -87º C or -125º F in winter, -5º C or 23º F in summer.
MARS• Fourth planet
• Two moons – Phobos and Deimos.
• Orbit – 687 days.
• Rotates every 25 hours. Has seasons.
• Thin atmosphere of carbon dioxide
• Surface temp.: -87º C or -125º F in winter, -5º C or 23º F in summer.
• No magnetic field.
• Water frozen under the surface.
• Largest volcano in solar system – Olympus Mons.
GAS GIANT PLANETS• The four outer planets made mostly of light
elements like hydrogen, helium, carbon and oxygen. In order from closest to the Sun: Jupiter, Saturn, Uranus and Neptune.
JUPITER• Fifth planet, largest planet.
• Made mostly of hydrogen and helium.
JUPITER• Fifth planet, largest planet.
• Made mostly of hydrogen and helium.
• Orbit – 4332 days or almost 12 years
• Rotates every 10 hours.
JUPITER• Fifth planet, largest planet.
• Made mostly of hydrogen and helium.
• Orbit – 4332 days or almost 12 years
• Rotates every 10 hours.
• Stripes are fast moving bands of clouds.
• Great Red Spot – giant anticyclonic storm, three whole Earth’s could fit inside.
JUPITER• Fifth planet, largest planet.
• Made mostly of hydrogen and helium.
• Orbit – 4332 days or almost 12 years
• Rotates every 10 hours.
• Stripes are fast moving bands of clouds.
• Great Red Spot – giant anticyclonic storm, three whole Earth’s could fit inside.
• 63 moons, 4 large ones: Io, Europa, Ganymede and Callisto
JUPITER• Fifth planet, largest planet.
• Made mostly of hydrogen and helium.
• Orbit – 4332 days or almost 12 years
• Rotates every 10 hours.
• Stripes are fast moving bands of clouds.
• Great Red Spot – giant anticyclonic storm, three whole Earth’s could fit inside.
• 63 moons, 4 large ones: Io, Europa, Ganymede and Callisto
• Magnetic field so large it reaches Earth.
• Has 4 small rings.
SATURN• Sixth planet, known for its rings.
• Made mostly of hydrogen and helium.
SATURN• Sixth planet, known for its rings.
• Made mostly of hydrogen and helium.
• Orbit – 10,759 days or over 29 years
• Rotates every 11 hours.
SATURN• Sixth planet, known for its rings.
• Made mostly of hydrogen and helium.
• Orbit – 10,759 days or over 29 years
• Rotates every 11 hours.
• 13 rings.
• 62 moons, one very large one: Titan.
• Moon Enceladus has ice volcanoes.
SATURN• Sixth planet, known for its rings.
• Made mostly of hydrogen and helium.
• Orbit – 10,759 days or over 29 years
• Rotates every 11 hours.
• 13 rings.
• 62 moons, one very large one: Titan.
• Moon Enceladus has ice volcanoes.
• Magnetic field about the same as Earth’s.
URANUS• Seventh planet, known for its funny name.
• First planet discovered with a telescope.
URANUS• Seventh planet, known for its funny name.
• First planet discovered with a telescope.
• Made mostly of hydrogen and helium.
• Coldest planet, covered with methane ice, ammonia ice and frozen water. “Ice Giant”.
URANUS• Seventh planet, known for its funny name.
• First planet discovered with a telescope.
• Made mostly of hydrogen and helium.
• Coldest planet, covered with methane ice, ammonia ice and frozen water. “Ice Giant”.
• Orbit – 84 years
• Rotates every 17 hours
URANUS• Seventh planet, known for its funny name.
• First planet discovered with a telescope.
• Made mostly of hydrogen and helium.
• Coldest planet, covered with methane ice, ammonia ice and frozen water. “Ice Giant”.
• Orbit – 84 years
• Rotates every 17 hours
• Tilted 97º on its side, probably from a collision.
URANUS• Seventh planet, known for its funny name.
• First planet discovered with a telescope.
• Made mostly of hydrogen and helium.
• Coldest planet, covered with methane ice, ammonia ice and frozen water. “Ice Giant”.
• Orbit – 84 years
• Rotates every 17 hours
• Tilted 97º on its side, probably from a collision.
• 11 rings, 27 moons named after Shakespeare characters.
• Has bands of clouds, spots like Jupiter.
NEPTUNE• Last planet, was predicted before it was
actually discovered.
NEPTUNE• Last planet, was predicted before it was
actually discovered.
• Made mostly of hydrogen and helium.
• Like Uranus, covered with methane ice, ammonia ice and frozen water. “Ice Giant”.
NEPTUNE• Last planet, was predicted before it was
actually discovered.
• Made mostly of hydrogen and helium.
• Like Uranus, covered with methane ice, ammonia ice and frozen water. “Ice Giant”.
• Orbit – 165 years, rotates every 16 hours.
• Five rings, 13 moons.
• Largest Moon, Triton, is coldest place in the solar system, orbits backwards.
NEPTUNE• Last planet, was predicted before it was
actually discovered.
• Made mostly of hydrogen and helium.
• Like Uranus, covered with methane ice, ammonia ice and frozen water. “Ice Giant”.
• Orbit – 165 years, rotates every 16 hours.
• Five rings, 13 moons.
• Largest Moon, Triton, is coldest place in the solar system, orbits backwards.
• Has bands of clouds, Great Dark Spot like Jupiter.
FORMATION OF THE SOLAR SYSTEM
• Stars start as giant clouds of dust and gas.
FORMATION OF THE SOLAR SYSTEM
• Stars start as giant clouds of dust and gas.
• These clouds start collapsing, maybe from a shock wave from a supernova.
FORMATION OF THE SOLAR SYSTEM
• Stars start as giant clouds of dust and gas.
• These clouds start collapsing, maybe from a shock wave from a supernova.
• Gravity takes over and pulls the cloud together into a hot ball.
FORMATION OF THE SOLAR SYSTEM
• Stars start as giant clouds of dust and gas.
• These clouds start collapsing, maybe from a shock wave from a supernova.
• Gravity takes over and pulls the cloud together into a hot ball.
• Starts spinning faster, and flattens out.
FORMATION OF THE SOLAR SYSTEM
• Stars start as giant clouds of dust and gas.
• These clouds start collapsing, maybe from a shock wave from a supernova.
• Gravity takes over and pulls the cloud together into a hot ball.
• Starts spinning faster, and flattens out.
• When it gets hot and dense enough in the center, nuclear fusion begins - a star is born.
FORMATION OF THE SOLAR SYSTEM
• Away from the sun, elements such as iron, silicon and carbon start to cool off and clump together.
• These clumps join together to form planetesimals, the beginnings of planets.
• Planetesimals join together and form planets.
FORMATION OF THE SOLAR SYSTEM
• Not all of the material in the solar system formed into planets:
FORMATION OF THE SOLAR SYSTEM
• Not all of the material in the solar system formed into planets:
• ASTEROIDS: leftover rocks found mostly between Mars and Jupiter.
FORMATION OF THE SOLAR SYSTEM
• Not all of the material in the solar system formed into planets:
• ASTEROIDS: leftover rocks found mostly between Mars and Jupiter.
• KUIPER BELT: thousands of icy and rocky bodies beyond Neptune such as Pluto, Eris, Haumea. (30 to 50 AU from the Sun)
FORMATION OF THE SOLAR SYSTEM
• Not all of the material in the solar system formed into planets:
• ASTEROIDS: leftover rocks found mostly between Mars and Jupiter.
• KUIPER BELT: thousands of icy and rocky bodies beyond Neptune such as Pluto, Eris, Haumea. (30 to 50 AU from the Sun)
• OORT CLOUD: cloud of ice and dust surrounding the solar system where most comets come from. (from 2,000 to 100,000 AU from the Sun)
IS THERE LIFE ELSEWHERE IN THE SOLAR SYSTEM?
• What are the conditions necessary for life to exist? Can they be found elsewhere than on Earth?
• CONDITIONS FOR LIFE:
IS THERE LIFE ELSEWHERE IN THE SOLAR SYSTEM?
• What are the conditions necessary for life to exist? Can they be found elsewhere than on Earth?
• CONDITIONS FOR LIFE:
1. LIQUID WATER.
IS THERE LIFE ELSEWHERE IN THE SOLAR SYSTEM?
• What are the conditions necessary for life to exist? Can they be found elsewhere than on Earth?
• CONDITIONS FOR LIFE:
1. LIQUID WATER.
2. SOURCE OF ENERGY (SUNLIGHT).
IS THERE LIFE ELSEWHERE IN THE SOLAR SYSTEM?
• What are the conditions necessary for life to exist? Can they be found elsewhere than on Earth?
• CONDITIONS FOR LIFE:
1. LIQUID WATER.
2. SOURCE OF ENERGY (SUNLIGHT).
3. MATERIALS, MINERALS.
IS THERE LIFE ELSEWHERE IN THE SOLAR SYSTEM?
• What are the conditions necessary for life to exist? Can they be found elsewhere than on Earth?
• CONDITIONS FOR LIFE:
1. LIQUID WATER.
2. SOURCE OF ENERGY (SUNLIGHT).
3. MATERIALS, MINERALS.
4. PROTECTION FROM RADIATION.
IS THERE LIFE ELSEWHERE IN THE SOLAR SYSTEM?
• MARS
• Frozen water under the surface.
IS THERE LIFE ELSEWHERE IN THE SOLAR SYSTEM?
• MARS
• Frozen water, maybe liquid under the surface.
• Red Planet – covered with iron oxide (rust).
IS THERE LIFE ELSEWHERE IN THE SOLAR SYSTEM?
• MARS
• Frozen water, may be liquid under the surface.
• Red Planet – covered with iron oxide (rust).
• Made of rocks similar to Earth.
IS THERE LIFE ELSEWHERE IN THE SOLAR SYSTEM?
• MARS
• Frozen water, may be liquid under the surface.
• Red Planet – covered with iron oxide (rust).
• Made of rocks similar to Earth.
• Thin atmosphere, but no magnetic field.
IS THERE LIFE ELSEWHERE IN THE SOLAR SYSTEM?
• EUROPA
• Liquid ocean under a frozen crust.
IS THERE LIFE ELSEWHERE IN THE SOLAR SYSTEM?
• EUROPA
• Liquid ocean under a frozen crust.
• Heat from the core.
• Made of rock with an iron core.
IS THERE LIFE ELSEWHERE IN THE SOLAR SYSTEM?
• EUROPA
• Liquid ocean under a frozen crust.
• Heat from the core.
• Made of rock with an iron core.
• Water protects you from radiation, and it has a magnetic field.
IS THERE LIFE ELSEWHERE IN THE SOLAR SYSTEM?
• GANYMEDE
• Made of layers of ice and rock.
IS THERE LIFE ELSEWHERE IN THE SOLAR SYSTEM?
• GANYMEDE
• Made of layers of ice and rock.
• Heat from the core could melt the ice and make a liquid water layer under the surface.
IS THERE LIFE ELSEWHERE IN THE SOLAR SYSTEM?
• GANYMEDE
• Made of layers of ice and rock.
• Heat from the core could melt the ice and make a liquid water layer under the surface.
• Convection in the core creates a magnetic field. Also has an atmosphere.
IS THERE LIFE ELSEWHERE IN THE SOLAR SYSTEM?
• TITAN
• Has a dense atmosphere of nitrogen and clouds of methane, an organic molecule. Covered with methane lakes.
IS THERE LIFE ELSEWHERE IN THE SOLAR SYSTEM?
• TITAN
• Has a dense atmosphere of nitrogen and clouds of methane, an organic molecule. Covered with methane lakes.
• Frozen water on the surface.
IS THERE LIFE ELSEWHERE IN THE SOLAR SYSTEM?
• TITAN
• Has a dense atmosphere of nitrogen and clouds of methane, an organic molecule. Covered with methane lakes.
• Frozen water on the surface.
• Heat from the core may melt some of the ice under the surface.
IS THERE LIFE ELSEWHERE IN THE SOLAR SYSTEM?
• TITAN
• Has a dense atmosphere of nitrogen and clouds of methane, an organic molecule. Covered with methane lakes.
• Frozen water on the surface.
• Heat from the core may melt some of the ice under the surface.
• Thick atmosphere, but no magnetic field.
