EQ: How has mankind’s need to explore led to our current view

of the solar system?

Warm Up – Page 160

• Copy today’s date and EQ: How has mankind’s need to explore led to our current view of the solar system?

• What do you know about how our views of the solar system have evolved since humans first gazed up at the stars?

• Imagine you live 5,000 years ago. When you look up at the night sky, what do you think about what you see?

Our First Views of the Universe

• Egyptians – need a way to predict the annual flooding of the Nile River

• Studied the star Sirius and noticed it was in the morning sky every spring shortly before the flooding began

Our First Views of the Universe

• Mayans – developed a calendar that was centuries before their time

• Observed the solstices

Our First Views of the Universe

• Stonehenge–Built in several stages–We don’t know who built it or exactly

why–It does have connections to the

summer and winter solstices

Our First Views of the Solar System: Reflect

• M: Restate the reason why Egyptians' exploration of the night sky was important.

• I: Which of the three ancient societies would you have preferred to explore the sky with? Why?

• U: What are the similarities in the explorations of the people who built Stonehenge and the Mayans?

• S: Imagine you are looking up at the stars in 3,000 B.C. How can you explore them?

Beginning to Make Sense of the Universe

• Greeks observed the planets.–Called them wandering stars–Were aware of 5 planets – Mercury,

Venus, Mars, Jupiter, and Saturn

Beginning to Make Sense of the Universe

• Aristotle–Placed the earth at the center of the

solar system surrounded by 55 crystalline spheres – GEOCENTRISM–Earth did not move at all–Everything revolved around the Earth

Beginning to Make Sense of the Universe

• Ptolemy–Refined geocentric model of the solar

system–Epicycles – smaller circles around large

circles to help explain planetary motion–Messy way to explain the movement

of planets

Epicycles

• Used to explain retrograde rotation – the apparent backward movement of planets

Beginning to Make Sense of the Universe: Reflect

• M: Summarize the contributions of Aristotle and Ptolemy to our understanding of the solar system.

• I: How would you feel if I told you the Earth really is the center of the solar system?

• U: Contrast Aristotle and Ptolemy’s discoveries about the solar system.

• S: Design a NASA mission patch dedicated to studying geocentrism.

Ticket in the Door

• On the index card, write/draw one of your two reflection responses from yesterday.

• Put if it is in response to the first (#1) or second ( #2) reflection.

• Don’t put your name.• Hold it up for me to pick up when you are

done.

The Revolution Begins

• Copernicus–Published Revolutionibus Orbium

Coelestium (On the Revolution of the Celestial Orbs) the year he died–Math based –Introduced the heliocentrism – the sun

is the center of the solar system

Copernican Solar System

The Revolution Begins

• Brahe – recorded many detailed astronomical observations – one of the first to make such detailed records

• Kepler – used Brahe’s date to develop his laws of planetary motion – planets orbit in ellipses

The Revolution Begins

• Galileo – first person to use a telescope to explore the

night sky; he became an expert at building refracting telescopes–Discovered evidence for heliocentrism• Jupiter – four moons that revolved around

it – not Earth• Venus – goes through phases like the

moon• Sun – has spots and rotates

The Revolution Begins

• Newton–Developed a new kind of telescope to explore

with – reflector–Wrote the Three Laws of Motion to explain

the movements of the planets– Planets are kept in orbit around the sun by• Inertia – objects in motion stay in motion• Gravity – force of attraction between

objects

The Revolution Begins: Reflect

• M: What do you think were the two most important discoveries made by these astronomers?

• I: Galileo’s findings were rejected the Catholic Church. How would you feel if you were Galileo?

• U: If everyone around you believes in a geocentric universe, hypothesize what their reactions would be when you explain heliocentrism to them.

• S: What would it be like to live on Jupiter and watch four moons orbit around your planet? What explorations would you conduct?

Our Growing Solar System

• Our continued need to explore has helped us learn more about the solar system and our views have changed over time because of that

Our Growing Solar System

• Uranus – discovered in 1781 by William Herschel using a telescope

• Ceres – discovered in 1801; started a big debate that led to the creation of the asteroid catergory

• Neptune – discovered in 1846 using a telscope

Our Growing Solar System

• Pluto – discovered in 1930 by Clyde Tombaugh

• Kuiper Belt – discovered in 1992 • As our tools become more advanced,

we continue to explore and learn about our solar system

Our Growing Solar System: Reflection

• M: What explorations led to Ceres no longer being considered a planet?

• I: If you were in charge of deciding where our next unmanned space probe will go in the solar system, where would you send it?

• U: Draw parallels between Ceres’ demotion from planet to asteroid and Pluto’s demotion from planet to dwarf planet.

• S: Imagine your patient observations night after night lead to the discovery of a new planet. How would you announce your discovery to the world?

Organize the Exploration!

• Create an illustrated timeline using a medium of your choice to organize the explorations that led to our current understanding of the solar system.