Earth and SpaceEarth and Space

Earth’s Place in SpaceEarth’s Place in Space

*Earth moves around the *Earth moves around the sun.sun.

A. Earth’s RotationA. Earth’s Rotation• Earth spins around an Earth spins around an

imaginary line running imaginary line running through its center called through its center called an an axis. axis. It is slightly It is slightly tilted.tilted.

• The spinning of Earth on The spinning of Earth on its axis is called Earth’s its axis is called Earth’s rotation.rotation.

• It rotates once every It rotates once every 24 24 hours (1 day and night).hours (1 day and night).

B. Earth’s RevolutionB. Earth’s Revolution• The movement of Earth around the sun The movement of Earth around the sun

in known as Earth’s in known as Earth’s Revolution.Revolution.• It takes Earth It takes Earth 1 year 1 year to complete one to complete one

revolution.revolution.

C. SeasonsC. Seasons• The Earth’s The Earth’s tilt tilt andand revolution revolution around the around the

sun causes seasons.sun causes seasons.• Summer Summer occurs when your part of the occurs when your part of the

Earth is tilted towards the sun. The days Earth is tilted towards the sun. The days are are long long and the nights are and the nights are short.short.

• Winter Winter occurs when your part of the occurs when your part of the Earth is tilted away from the sun and the Earth is tilted away from the sun and the slanted rays of the sun are slanted rays of the sun are weak. weak. The The days are days are short short and the nights are and the nights are long.long.

• Spring Spring andand fall fall occur when Earth is not occur when Earth is not tilted toward or away from the sun.tilted toward or away from the sun.

D. Movements of the MoonD. Movements of the Moon• The The moon moon constantly circles the Earth as Earth constantly circles the Earth as Earth

revolves around the sun.revolves around the sun.• Although it looks different at different times of Although it looks different at different times of

the month, the month, it doesn’t changeit doesn’t change – the way we see – the way we see it does.it does.

• The The sunsun lights up the moon. lights up the moon.• The movement of the Earth is what causesThe movement of the Earth is what causes night night

and day.and day.

D. Movements of the D. Movements of the Moon (cont.)Moon (cont.)

• When the moon and When the moon and sun are on opposite sun are on opposite sides of Earth, a sides of Earth, a fullfull moon occurs.moon occurs.

• When the moon and When the moon and sun are on the same sun are on the same side as Earth, a side as Earth, a new new moon occurs. This is moon occurs. This is when the side of the when the side of the moon that is lit by moon that is lit by the sun faces the sun faces away away from Earth.from Earth.

Full Moon

New Moon

Phases of the MoonPhases of the Moon

• Solar Solar eclipse: when the moon is between eclipse: when the moon is between the Earth and Sun.the Earth and Sun.

Diagram of a Solar Eclipse

Total Solar Eclipse (2001)

LunarLunar eclipse: when the Earth is between eclipse: when the Earth is between the sun and moon.the sun and moon.

Stages of a Lunar Eclipse

Space – How are we Space – How are we connected?connected?

Universe GalaxyUniverse Galaxy

Milky WayMilky Way

Our Solar SystemOur Solar System

• Universe: Universe: the vast the vast expanse of space expanse of space which contains all of which contains all of the matter and energy the matter and energy in existence. in existence. EVERYTHING is a part EVERYTHING is a part of it. IT IS HUGE!!!of it. IT IS HUGE!!!

• Galaxy: Galaxy: a cluster of a cluster of starts, dust, and gas starts, dust, and gas which is held together which is held together by gravity. by gravity. Astronomers suggest Astronomers suggest there may be as many there may be as many as 100 billion!! They as 100 billion!! They are scattered are scattered throughout the throughout the universe and vary universe and vary greatly in size.greatly in size.

The Universe (several galaxies can been seen)

Spiral Galaxy

*Galaxies are classified by scientists according to their *Galaxies are classified by scientists according to their sizesize and and shape.shape.

1. 1. irregular – irregular – no definite shapeno definite shape2. 2. spiral – spiral – pinwheel shape (our galaxy)pinwheel shape (our galaxy)3. 3. elliptical – elliptical – go from round to go from round to

flat discs flat discs*galaxies range from a few *galaxies range from a few thousand thousand to a to a million million light years in diameter.light years in diameter.

Spiral (Andromeda) Elliptical Irregular

Solar SystemSolar System

Made up of Made up of 88 planets and other objects planets and other objects that orbit the sun.that orbit the sun.

To measure distances in space, scientists To measure distances in space, scientists use an use an astronomical unitastronomical unit (AU). 1 AU = 150 (AU). 1 AU = 150 million km, which is the average distance million km, which is the average distance from Earth to the sun.from Earth to the sun.

A A light yearlight year is 9.5 trillion is 9.5 trillion (9,500,000,000,000) kilometers and is the (9,500,000,000,000) kilometers and is the distance light travels in one year.distance light travels in one year.

PlanetPlanet: round ball of : round ball of gas or rock that gas or rock that travels around a travels around a star – and the path star – and the path it takes around a it takes around a star is called its star is called its orbitorbit..

Inner Planets: Inner Planets: Mercury, Venus, Mercury, Venus, Earth, MarsEarth, Mars

Outer Planets: Outer Planets: Jupiter, Saturn, Jupiter, Saturn, Uranus, Neptune.Uranus, Neptune.

Saturn is Saturn is notnot the the only planet with only planet with rings. Jupiter, rings. Jupiter, Uranus, & Neptune Uranus, & Neptune do too.do too.

Pluto is now Pluto is now considered a considered a dwarf dwarf planetplanet..

The Stars and SunThe Stars and Sun The stages a star goes through in its The stages a star goes through in its

life depend on the star’s life depend on the star’s sizesize.. The smallest stars shine the The smallest stars shine the longestlongest.. Scientists hypothesis that stars begin Scientists hypothesis that stars begin

their lives as their lives as nebulaenebulae (clouds of gas (clouds of gas and dust).and dust).

A large-size star can end its life cycle A large-size star can end its life cycle as a neutron star or a as a neutron star or a black holeblack hole..

The sun is a The sun is a mediummedium-sized star.-sized star.

The Stars and Sun, cont.The Stars and Sun, cont. In about 5 billion years our sun will In about 5 billion years our sun will

become a become a giant.giant. At the end of our sun’s life cycle, it will At the end of our sun’s life cycle, it will

become a become a black dwarf.black dwarf.

The Sun and Stars, cont.The Sun and Stars, cont.

ConstellationsConstellations: patterns formed by : patterns formed by groups of stars.groups of stars.*They are named for people, animals, or *They are named for people, animals, or

commons objects and were used as commons objects and were used as reference points in the sky by sailors.reference points in the sky by sailors.

*Because the Earth is moving, the stars that *Because the Earth is moving, the stars that are visible at night constantly change.are visible at night constantly change.

*As the Earth revolves around the sun, *As the Earth revolves around the sun, different constellations are seen different constellations are seen throughout the year.throughout the year.

Examples of Examples of Constellations…Constellations…

The Big Dipper (Ursa Major) The Little Dipper (Ursa Minor)

Our GalaxyOur Galaxy Our galaxy is called the Our galaxy is called the Milky Way.Milky Way. The shape of our galaxy is The shape of our galaxy is spiralspiral (looking down it (looking down it

looks like a pinwheel)looks like a pinwheel) It contains: It contains: stars stars (billions!), (billions!), nebulae nebulae (clouds of (clouds of

dust and gas)dust and gas), planets, , planets, andand asteroids. asteroids. It is approximately It is approximately 100 light years 100 light years in diameter.in diameter. All objects in the Galaxy revolve around the All objects in the Galaxy revolve around the

Galaxy’s Galaxy’s center.center. It takes the Sun It takes the Sun 250 million years250 million years to pull us to pull us

through through 11 revolution around the center of the revolution around the center of the Milky Way.Milky Way.

The Milky Way GalaxyThe Milky Way Galaxy