Earth ScienceChapters 10 & 11

Chapter 10- Earth & Its Moon

Lesson 1- Earth’s SeasonsObjective- In this lesson, we will learn how

the Tilt (position) of the Earth’s Axis will cause seasons

Earth’s Tilted Axis

Earth rotates constantly on its axis It takes almost 24 hours

for Earth to make a complete rotation on its axis (equal to one day)

As Earth spins, different parts of it face and turn away from the Sun.This creates day and

night

As Earth spins on its axis, it also revolves around the Sun.

One full trip around the Sun is a Revolution It takes about 365 days, or 1 yr.

Earth’s orbit is in an ellipse shapeBecause of Earth’s tilted axis, some areas

experience severe seasons, while others (near equator) do not.

SolsticesThere are two solstices

throughout the year.Winter Solstice- December 21 or

22First day of WinterLeast amount of daylight all year

Summer Solstice- June 21 or 22Beginning of summer in N.

HemisphereLongest amount of daylight all year

Equinoxes- Periods of daylight are equal

Autumnal Equinox-September 22 or 23First day of Fall

Vernal EquinoxMarch 20 or 21First day of Spring

SeasonsAll places on Earth

have four seasons.Places near the Poles

have lower average temperatures than places near the EquatorThis is caused by

amount of sunlight the area receives

Lesson 2- Earth’s Moon

The Moon• The moon is a natural

satellite that revolves around the Earth

• It is ¼ the size of Earth

• Mass is 80 times lighter than Earth’s

• It has less gravity than Earth

Viewing the Moon

The moon seems so large because it is closest to Earth than any other object in space. ( it’s actually smaller than Earth)

Moon doesn’t produce any light. Sun reflects light off its surface

Moon revolves around Earth, while it rotates on an axis.Takes 27 and 1/3 days to revolve, and rotate once

around Earth.Same side of the Moon ALWAYS faces the Earth.

Phases of the Moon

One side of the Moon (half) is always lit by the Sun.The different shapes

created by the visible light are Moon Phases

Different parts of the Moon’s lit side are visible on EarthTakes about one month

to complete one Moon phase cycle.

Phases of the Moon

New Moon- the Moon is between Earth and the Sun. Because its lighted side is facing away from Earth, the Moon appears dark when viewed from Earth.

Waxing Crescent- appears after the new Moon phase. The sunlit portion is increasing, but less than half.

The first quarter and third quarter moons (both often called a "half moon"), happen when the moon is at a 90 degree angle with respect to the Earth and Sun. So we are seeing exactly half of the moon illuminated and half in shadow.

Waxing Gibbous- After the first quarter, the sunlit portion is still increasing, but now it is more than half.

At a full moon, the Earth, Moon, and Sun are in approximate alignment, just as the new moon, but the moon is on the opposite side of the earth, so the entire sunlit part of the moon is facing us. The shadowed portion is entirely hidden from view.

http://www.moonconnection.com/moon_phases_calendar.phtml

Waning Gibbous- After the full moon (maximum illumination), the light continually decreases.

Following the third quarter is the waning crescent, which decreases until the light is completely gone -- a new moon.

EclipsesEclipses

An Eclipse occurs when one object passes into the shadow of another object

In order for one to occur, Earth, Sun and the Moon must all be aligned

During a Total Eclipse, two types of shadows formUmbra- smaller, darker area, in PenumbraPenumbra- Larger, lighter area

Solar EclipseSolar Eclipse

Occurs when the moon passes between the Sun and Earth

Moon casts a shadow on EarthDuring the DayMoon blocks out the

sunlight.Sun appears Black

Lunar EclipseLunar Eclipse

Takes place when the Earth passes directly between the Sun and Moon.

Moon moves into Earth’s shadowOccurs at night/duskMoon appears to be a

reddish color

Chapter 11- Exploring Space

Lesson 1- The Solar System

The Sun and Its Neighbors

The Sun and the bodies that orbit around it make up the solar system.

Sun is largest in solar systemEarth is one of eight planets in

the solar system.Scientists believe that the solar

system is about 4.6 billion years old.

The strong gravitational force of the Sun holds all other objects in their orbits.

MoonsThere are about 140

moons in the solar system.

Some moons have their own atmosphere, unlike Earth’s moon.

All are held in orbit by the gravity of their planet.

Asteroids

A small rocky object that orbits the Sun.

Most are in a band between Jupiter and Mars, called the asteroid belt.

There are many theories about how asteroids formed.

CometsSmall bodies made of dust, ice and frozen

gases.Orbit the Sun in long elliptical orbits.A Coma is a glowing region formed from

gases and dust of frozen solids.Tail of a comet always faces away from

the Sun.

Famous CometsHalley’s Comet- short-

period comet that orbits the Sun about every 76 years. Visible from Earth

again in 2061Hale-Bopp Comet-

Long-period comet, takes about 2500 years to orbit the Sun.

Meteors and MeteoritesMeteors are small chunks of matter that enter

into Earth’s atmosphereMost burn up in the atmosphere, never striking Earth

When many are visible at once, this is called a Meteor shower

A meteor that does strike Earth is called a MeteoriteWhen large ones strike Earth, they form impact craters

Lesson 2- What are the Planets Like?

The Inner Planets

Inner Planets are rocky and small

There are 4 inner planetsMercury- smallest and

closest to the Sun. Side facing the Sun is

very hot, facing away from the sun is very cold.

Many craters on the surface

Venus

Venus- is the second planet from the SunThick atmosphere of

clouds made of sulfuric acid.

Hot temperatures on surface

Extreme atmospheric pressure

Earth

Earth- 3rd planet from the SunOnly planet known to

have liquid waterAtmosphere and

oceans make it the only planet in solar system known to support life

Mars

Mars- 4th planet from the SunKnown as the Red

PlanetSmaller than Earth but

same amount of land area.

Home to largest volcano in the solar system

Planet most like EarthMost explored planet,

Mars Expedition Rovers

Outer Planets

There are four outer planetsMost are huge and made of gasesThey have many moons and one or more

rings.Pluto (dwarf planet) is the only exception

Jupiter

5th planet from the Sun, and one of the brightest objects in the sky

Biggest and most massive planet in the solar system

Famous for its Great Red Spot, a gigantic storm system

More than 60 moons.

Saturn6th planet from the

SunBest known for its

rings, mostly made of ice particles

Least dense of all planetsHolds more than 30

moons in its orbit

Uranus7th planet from the SunAxis is tilted so much,

it looks like it on its side

Consists mostly of gases

11 rings, and 27 moons

High amount of methane give it the greenish color

Neptune

8th planet from the Sun

Has 11 moons, Largest moon is TritonNeptune is getting

closer to Triton, and will probably collide in the next 100 million yrs.

Coldest surface in the solar system

Pluto

Farthest from the SunRecently (2006)

discovered as a Dwarf Planet

Very coldHas one moon called

CharonUnlike other outer

planets:Small, icy, rocky

Exploring SpaceOptical telescopes are used to

explore solar systemThe space shuttle takes equipment

and people into spaceSpace stations stay in space for

long periods of time, astronauts can live, sleep and conduct experiments

Space Probe- spacecraft that carries special instruments into space launched into Earth’s upper

atmosphere Mars Rover- explored Mars, taking

pictures and samples

Lesson 3- What Are Stars Like?

Earth’s Star: the SunStar- large sphere of glowing gases

Defined by its size and temperatureSun is a yellow star made mostly of

hydrogen and heliumA light-year (Ly)- used to measure outside

of the solar systemDistance light travels in about 1 yr.

Magnitude- brightness of a starStars closer to Earth appear brighter

Constellations- arranged patterns of starsBig Dipper

A Star is Born

Stars begin as rotating clouds of gas called nebulas

Cloud rotates faster and forms first stage to a star called a protostar

Main Sequence star- continues to release energy, w/ nuclear reactionsHottest, brightest stars are blue or white in colorMedium sized are yellow or orangeDimmest and coolest are Red.

Sun is a medium star, halfway through its life cycle

Red Giant Phase- after a main sequence White Dwarf phase a. Medium sized stars move here b. Beginning of dying stage, starts to

run out of “fuel” c. Becomes a black dwarf- star that

gives off NO LIGHT

Supernova a. A very massive star that will explode

from its center.

o Larger remnants will become a Black hole i. powerful gravitational pull, and

collapses onto itselfo Smaller masses will become a Neutron

star i. dense, rapidly spinning star

Galaxies

Enormous system of gases, dust and stars held together by gravity

Most stars have 2 main parts- Bulge Halo

Milky Way

Galaxy of our solar system

Spiral Galaxy

More than 200 billion stars

Types of Galaxies

Spiral Galaxy- has a bulge, disk and halo, and arms that extend

Elliptical Galaxy- Shaped like a flattened ball Brighter in the center

Irregular Galaxies no real shape or structure large regions of hydrogen gas and hot star