Unit 2: Astronomy Earth Science- Ms. Gill Note Packet #3B

Name: ___________________________ Period: _____ Date:__________________

C. Our Solar

System:

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Mythology The Sun God. Greeks Called it Hellos

Mass 333 400 times the mass of the Earth

Diameter 1 392 000 km (109 x Earth’s diameter)

Gravity 28 times that on Earth

Surface Temperature6000°C (average). From 4500 to 2000000°C up to 15000000°C in the core.

Period of rotation (day)Equator 26 Earth days, poles 37 Earth days

Tilt of axis 122°

A. Which is bigger: Our Solar System or Our Sun?Naturally our ____________________ is bigger since the sun is apart of it. An object must always be bigger than something it includes. For example, a shoebox must always be bigger than the shoes. And your shoe must be big enough to fit your foot.

B. Our Sun:-The sun is a star.

-A ball of hot glowing gases.

-It gets hotter as you go deeper.

-Central force that has a high influence on planets orbits.

-Without the sun’s energy and heat there would be no life on Earth

-It holds everything in place by its gravity.

-It contains about 99% of the mass of the solar system.

Unit 2: Astronomy Earth Science- Ms. Gill Note Packet #3B

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The Solar System includes: The Sun, a ______________size, middle-aged star The eight planets and associated moons ________________chunks of rock found mostly in a belt between Mars and Jupiter __________________– mass of frozen gas and rock These are considered __________________ which appear in the sky during day

and night.

D. The Formation of Our Solar System:

______________________ large cloud of gas, ice & dust existed

It began to contract & slowly rotate Contraction increased density & rotation Gravity began to pull material toward the

center Density increases = increased rotation &

gravity Begins to form disk with large center Central mass begins to heat up due to

contraction Temperatures reach 10 million °Kelvin Hydrogen atoms begin to fuse together

forming Helium Fusion occurs, driving the formation of our

Sun The material outside the central mass

forms planets

E. The Parts of Our Solar System:

The ______ is the center of the Solar System

_______________, also called ___________: (meaning earth-like) the first four planets

__________________: band of rocks orbiting the sun

________________, also called ___________: the four planets farthest from the sun.

Size Comparison Jovian vs. Terrestrial

Unit 2: Astronomy Earth Science- Ms. Gill Note Packet #3B

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Terrestrial Planets: Four ___________ planets of the

solar system Relatively __________ in size and

mass (Earth is the largest and most massive)

__________ surface Surface of Venus cannot be seen

directly from Earth because of it’s _______________________.

Jovian Planets: Much _____________ in mass and

size than terrestrial planets Much lower average

___________________ All have rings (not only Saturn!) Mostly _________; no solid surface Also known as Gas Giants because

they are made of mostly hydrogen and helium

Asteroids Rocky objects with ____________ or _____________ shapes Most orbit in a wide belt between _________ and ____________ The total mass of all the asteroids is less than that of the Moon Believed to be a planet that never formed Range in size from dust to almost Moon size Photographed by Galileo probe Some Named Asteroids:

Ceres: 940 km (Largest known) Pallas: 523 km Vesta: 501 km Juno: 244 km Gaspra & Ida:

Comets: Only visible when they are close to the ________ Icy nucleus, which evaporates and gets blown into

space by solar wind pressure. Mostly objects in highly _____________ orbits,

occasionally coming close to the sun Comet Composition: Dust, rock, frozen methane,

ammonia, and water Comets normally look like dirty ________________ When they get close to stars, they begin to vaporize

& _______________. Forms a coma (tail) from the nucleus (head) ___________: glowing trail of particles which

always points away from the star Comets eventually break up into space debris Oort Cloud: large collection of comets beyond

________

Unit 2: Astronomy Earth Science- Ms. Gill Note Packet #3B

Planets: A planet is a body that is in orbit around the Sun, has enough mass for its self-gravity to overcome forces (nearly round) shape, and clears the neighborhood around its orbit. Planet order (closest to the sun to furthest): Write one interesting fact about each:

MERCURY: ________________________________________________________

VENUS: __________________________________________________________ EARTH:

__________________________________________________________

MARS: ___________________________________________________________

JUPITOR: ________________________________________________________

SATURN: _________________________________________________________ URANUS:

_________________________________________________________ NEPTUNE:

________________________________________________________

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Meteoroids, Meteors & Meteorites:Meteoroids: chunks of randomly moving through space. Usually leftover comet or asteroid debrisMeteor: Meteoroid that collides with Earth, evaporates in the atmosphere producing streaks of visible light (“shooting stars”) Most burn up before reaching the surfaceMeteor Shower: Many meteors at one time Meteorite: Meteor that does not totally burn up, & strikes the Earth’s surface.

How do the Planets move around the Sun? All planets move in the same plane (a large imaginary flat surface) Orbits generally inclined by no more than 3.4o except for Mercury at 7° All planets in almost circular (elliptical) orbits around the sun Sense of revolution: counter-clockwise Kepler’s Laws govern the planets’ orbits

Unit 2: Astronomy Earth Science- Ms. Gill Note Packet #3B

EccentricityThe _________ of an

ellipse is how much it varies from a true circle. The __________ the number, the closer the orbit is to a perfect circle.

Formula for eccentricity: Eccentricity=

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Orbits ____________ – the movement of an object around another object __________ – the path taken by a revolving object Celestial objects have _______________ orbits Velocity changes during revolution; planets further from Sun revolve

slower

Elliptical Orbit A circle has one central point, called a __________. Ellipses have two points, called __________. Therefore an ellipse is not a perfect circle. Eccentricity is a measure of how off the ellipse is

from being a perfect circle.

Calculate the eccentricity of the ellipse below:

foci foci

Regents Question: Which object is located at one foci of the elliptical orbit of Mars? (1)the Sun (3)Earth (2)Betelgeuse (4)Jupiter

Unit 2: Astronomy Earth Science- Ms. Gill Note Packet #3B

Know when to use your ESRT!

The Three Kepler’s Laws: 1. Planets move around sun in elliptical orbits. Sun is at one focus point.

2. Planet moves faster when closer to the Sun due to gravitational pull of the Sun.3.The greater the distance from the sun, the longer the period of revolution

because Longer orbits and Slower orbital velocities.

Orbital Energy ______________ – the force of attraction between 2 objects ______________ – the tendency of an object in motion to continue in motion

along a straight path The interaction of gravity and inertia keep planets in __________

Energy Transfer Energy is transferred between ___________ and ______________ as a planet

orbits the Sun.

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Laws of Planetary Motion Devised by German astronomer Johannes Kepler He discovered the line joining the Sun and a planet sweeps equal areas in

equal intervals of time

Unit 2: Astronomy Earth Science- Ms. Gill Note Packet #3B

Orbital Velocity The Earth’s orbital velocity is _____________ when kinetic energy is the

highest. This occurs when the Earth is ___________ to the Sun in its orbit.

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