Download Objects in the Universe

Universe Recap / Objects in
the Universe
Universe / Gravity Recap
• Which planet has the lowest gravity?
• Pluto (Dwarf Planet)
• Which planet has the highest gravity?
• Jupiter
• On which planet were you the “lightest”?
• Pluto
• On which object were you the “heaviest”?
• Neutron Star
• Why do you think you were the heaviest on that object?
• It has the most gravity
Universe / Gravity Recap
• Define mass
• How much matter an object contains
• Define Weight
• Force of attraction between you and the Earth
• What does the force of gravity depend on?
• Your mass
• Mass of the Planet you’re on
• Distance from the center of the planet
• What equation can we use to determine the force due to gravity?
• F = Mm
r2
Universe / Gravity Recap
• Between mass and weight which one changes
depending on which planet you’re on?
• Weight. Mass stays constant but weight depends
on gravity
• Why did you have to jump 5 times?
• To eliminate any experimental errors
Universe / Gravity Recap
• On which moon/planet could you jump the furthest?
• Moon
• On which planet would you jump the shortest?
• Jupiter
• Why would you jump the shortest on that planet?
• It has more gravity so you would be “weighed”
down.
Objects in the Universe
• Planets
• Moons
• Small Bodies in solar system with weak gravity and no
atmosphere
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Dwarf Planets
Comets
Asteroids
Meteoroids
What is a planet?
• A planet is a celestial body that
• (a) has sufficient mass for its self-gravity assumes a nearly round
shape, and
• (b) is in orbit around a star, and is neither a star nor a satellite of a
planet
• But with this, Pluto should be a planet.
Theory changed
• A planet is a celestial body that
• (a) has sufficient mass for its self-gravity assumes a nearly
round shape, and
• (b) is in orbit around a star, and is neither a star nor a
satellite of a planet, and
• (c) has cleared the neighborhood around its orbit
• Is pluto a planet then?
Objects in the Universe
• Planets
• Moons
• Small Bodies in solar system with weak gravity and no
atmosphere
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Dwarf Planets
Comets
Asteroids
Meteoroids
Dwarf Planets
• Orbits sun
• Has own gravity
• Not enough mass to clear items out of orbit
• 5 Dwarf planets
Comets
• Small body of ice, rocks and dust
• “Dirty Snowballs”
• Gives off dust and gas in form of a tail when it gets
close to the sun
• Tail always points away from the sun
Asteroids
• Small, irregularly shaped, rocky object
• Most are located between Mars and Jupiter
• Asteroid Belt
• Hundreds of thousands of asteroids
• 570km to 4 m in diameter
Meteroid
• Rocky Body that varies in size. Smaller than
asteroid
• Enters Earths atmosphere and can become
either a meteor or meteorite
• Meteor: Bright streak of light. Meteroid burns up
as it enters atmosphere
• Meteorite: Meteroid that reaches Earths surface
and doesn’t burn up