how did earth form?. collapsing interstellar clouds stars and planets form from clouds of gas and...
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 systemMost 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 Earth’s atmosphere
Meteorite – A meteor that does not complete burn up in atmosphere and strikes Earth’s surface
Less than 100 m in diameterMove at fast speeds
Comets
Small bodies of rock and ice that have highly eccentric orbits
Periodic Comets – repeatedly return to inner solar system Halley’s 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