Early Astronomers

Intro to Astronomy Unit

Ancient GreeksBiography Aristotle (384-322 BC)

Major Contributions Proved that the Earth

is round using math and observations.

Claudius PtolemyBiography Greek Lived ca. AD 83-168

Major Contributions Created the Geocentric

model of the solar system in which the Earth was the center.

Nicolaus Copernicus

Biography 1473-1543 From Poland

Major Contributions Earth as a planet Model of the solar system

with the sun at center called the Heliocentric model.

Proved that Earth rotates

Johannes KeplerBiography 1571-1630 Danish Brahe’s assistant Mathematical *New astronomy*

Major Contributions Discovered 3 laws of planetary

motion:1) Planet’s orbit is an ellipse (oval)

shape2) The planets move faster when

nearer the sun and slower when farther away

3) A planet’s orbital distance determines its distance from the sun

Defined the term astronomical unit as the average distance between the Earth and the sun (approximately 150 million km)

Galileo GalileiBiography 1564-1642 Italian

Major Contributions Galileo used a telescope to

make better observations. 1. Four “satellites” or moons

orbiting Jupiter2. Planets are circular disks,

not just points of light3. Venus has phases just

like the moon

Sir Isaac NewtonBiography 1642-1727 English

Major Contributions Formulated the law of

universal gravitation saying that all objects have gravity between them.

Explained the laws of inertia and gravity.

Inertia says that an object in motion will stay in motion till acted on by another force.

Contemporary AstronomersEdwin Hubble

Biography Born: 11/20/1889 Died: 9/28/1953 American

Stephen Hawking

Biography Born:1/8/1942 British

Major Contributions Explained that the universe

was and still is expanding Has a telescope that orbits in

space named after him. The Hubble Space Telescope

Major Contributions Theorized the existence of

black holes.

Geocentric Model/Earth Centered

Heliocentric Model/ Sun Centered

Geo and Heliocentric Geocentric meaning Earth Centered was

created by Claudiaus Ptolemy. He thought the earth was the center of everything in the Solar system.

Heliocentric meaning Sun Centered was created by Nick Copernicus and he thought and proved that the sun was the center of the solar system and every thing revolves around the sun.

Astronomical Unit The time it takes for light to travel from the

sun to earth is 1 AU. ABOUT 150 MILLION KILOMETERS…….

Light Year- The distance light travels in 1 year Light Minute- The distance light can travel in

1 minute Light Hour- The distance light can travel in 1

hour.

The Big Bang Theory

Big Bang Theory is where a nebula cloud of rotating gases and rock; condensed, heated then cooled and collapsed. As a result this created our galaxy and solar system.

Order of Formation

Big Bang

1. Galaxies

2. Solar system

3. Sun

4. Earth

Big Bang Order of Formation

As this cloud of gases and rock condensed and exploded, several things formed.

The first thing that formed was the different Galaxies. There are 3 types of galaxies. Our Galaxy is the Milky Way. Yummmmm!

The second thing that formed was the Sun. It provided heat for the planets, including earth.

Next and last they earth began to take shape, form and grow.

Types of Galaxies

What is a galaxy?

A galaxy is a huge cluster of stars, dust, and gas held together by gravity.

Large galaxies have more than a trillion stars while small galaxies have fewer than a billion.

Astronomers believe that there are billions of galaxies in the universe.

Basic Types of Galaxies

Elliptical

Spiral

Irregular

Spiral Galaxy Shaped like pinwheels Sweeping “arms” made

of gas, dust, and younger stars, rotate around the galaxy’s center called a bulge.

The bulge is a dense group of old stars

Our Milky Way Galaxy is a Spiral Galaxy.

Milky Way Galaxy Our solar system

is located on one of the spiral arms called the Orion Arm.

All of the stars we see at night are part of the Milky Way Galaxy.

Elliptical Galaxies Among the largest

galaxies in the universe Looks like a snowball Contains mostly older

stars that rotate around the center of the galaxy in an unorganized fashion

Elliptical Galaxy

Irregular Galaxies Least common type of

galaxy Smaller and shapeless Contains very hot

newer stars and older stars

May form when two galaxies collide

Irregular Galaxy

Gravity Gravity is the force between all objects that pulls

them together. Gravity Keeps the planets in orbit around the sun.

Gravity keeps you and all objects on earth. 2 factors affect gravity- Mass of an object and

distance between objects. For example- Mercury has more gravity to the sun

than earth because the distance is shorter between them.

Inertia

Inertia is a law that states that all objects will stay in motion until stopped by another force.

For example- gravity holds the planets in orbit but inertia keeps the planets moving.

The moon has both gravity and inertia.

Our 8 Planets

Mr. Smith

Made of mainly gases. Much larger than any planet in the solar system. Creates the gravity needed to hold planets in orbit. The sun is the only star in our solar system. All

other stars are in our galaxy outside our main system.

As you look into the night sky, your seeing our galaxy and solar system.

The Sun

The sun is made up of 6 parts; The Corona, Chromospheres, photosphere, Convective zone, radiative zone and the core.

When you look at the sun your seeing the Photosphere.

The Corona is the suns atmosphere The Convective zone is where the gases circulate The core is where the gases are burning

Continued……Sun

Will the sun burn out or shrink? Scientist have found out that the suns energy

comes from nuclear fusion. Fusion is the joining of two atoms to create energy. The energy created from hydrogen atoms fusing

creates helium atoms. It then gets sent into other layers and eventually reaches the surface in the form of light energy.

Continued……Sun

Sun

1st planet from the sun Shortest revolution/year=88 earth days Rotation/day=58 earth days Rotates retrograde (clock wise) Much smaller than earth and the smallest planet Its atmosphere is made of Oxygen, sodium, helium Mercury is a terrestrial planet Terrestrial means the type of surface Mercury has little to no atmosphere and manly composed

of Oxygen, sodium and helium. Temperature ranges from -297 at night and 872 degrees F

during day.

Mercury

Mercury

2nd planet closest to the sun and the planet before earth.

Most like the Earth Slightly Smaller than earth Retrograde rotation- Counter clockwise 2nd fastest revolution of all planets Covered by a layer of clouds that trap heat and

covered by volcanoes. Temperature=856 degrees F Atmosphere made of carbon dioxide(soda’s) Rotation= 243 earth days) Revolution= 224 earth days/ 1venus year

Venus- When a volcano meets a tornado!

Venus

Most complex planet with every system- water, air, land and life.

5th largest in solar system 23 degree tilt on axis 70 percent of earth is covered by water Mostly 0-100 degrees Atmosphere 78% nitrogen and 21% oxygen 3 layers of surface- Crust, mantle and core Revolution= 365 days in Rotation=24 hours Prograde Rotation which means counter

clockwise.

Earth- The 3rd rock from the sun!

Earth and moon

Often called the Red Planet, Mars means God of War Known to have water in its polar area that is frozen. Atmosphere made of Carbon Dioxide Temperature ranging from -225 to 62 degree F. 7th largest planet 4th shortest year/4th shortest revolution around the sun. Takes 1.8 earth

years. Has the Largest Volcano in the solar system called Olympus Mons, 15

miles high and 400 miles wide Rotation= 24 hr 37 min Revolution= 1.88 earth years/ 1 mars year

Mars

Mars

Mars and its moons

Jupiter Jupiter’s name means, King of the Roman Gods First of the Gas Giants and majority of the planet is made of gas/very little is solid. The largest planet in the solar system Rotation/day=9 earth hours Revolution/year=11.8 earth years Atmosphere made of Hydrogen and Helium Has 28 moons. The 4 largest are called the “Galician Satellites” named after

Galileo who found them. 318 times the size of Earth Known for having “the Great Red Spot” which is a Hurricane on the surface of

Jupiter.

Jupiter

Jupiter's moons

Saturn

Saturn’s Moons

Neptune

Neptune’s Moons

Uranus

Uranus Moon’s