Presentation on theme: "How did Earth form?. Collapsing Interstellar Clouds Stars and planets form from clouds of gas and dust, called interstellar clouds Consist of gas: Hydrogen."— Presentation transcript:
How did Earth form?
Collapsing Interstellar Clouds Stars and planets form from clouds of gas and dust, called interstellar clouds Consist of gas: Hydrogen and Helium Usually low density, can condense due to gravity and form a star or a planet.
At first the collapse is slow, but it accelerates and the cloud soon becomes much denser at its center. It will spin faster and faster as it contracts (ice skater pull arms to body to spin faster) Eventually slows and cloud becomes flattened, becoming a rotating disk.
Sun and Planet Formation The disk of dust and gas that formed the Sun and planets is known as the solar nebula. Dense concentration at center became the Sun.
Temperature differed, Hotter at center and cooler at edges of disk Due to temp differences different compounds were able to condense depending on distance from Sun
Condensed material accumulated to from larger bodies. Planetismals – Space object built of solid particles that can form planets through collisions and merges Overall result was the planets
Early Planets Jupiter formed first, using much of the material around it This is why Jupiter is the largest Planet The sun took most of the gas from the inner planets This is why they are solid with few moons
Debris Most collided into planets or was sent out of the solar system. The remnants remain in the asteroid belt between Jupiter and Mars. Jupiter's gravitational force prevents them from forming into a planet.
Asteroids Rocky remnants of the early solar system Most are less than 1 km in diameter, move slowly C – Type (Carbon) S – Type (Silica) M - Type (Iron-Nickel) Asteroid Belt (Between Mars and Jupiter)
Meteoroid – asteroid that begins to fall towards Earth Meteor – Meteoroid that begins to burn up in Earths atmosphere Meteorite – A meteor that does not complete burn up in atmosphere and strikes Earths surface Less than 100 m in diameter Move at fast speeds
Comets Small bodies of rock and ice that have highly eccentric orbits Periodic Comets – repeatedly return to inner solar system Halleys Comet (76 Years, last seen 1985) Kuiper Belt – Located Beyond Neptune Come very close to Pluto in Aphelion, near sun at Perihelion
Parts of a Comet Coma Extended volume of glowing gas Nucleus Small solid core of the comet Tail
Comet tails ALWAYS point away from sun When come within 3 AU of the sun begin to evaporate Gas and dust pushed away by radiation from sun Meteor Shower – Earth intersects cometary orbit. Particles burn up in atmosphere