1. Earth and Space Science
Origin of Modern Astronomy
Chapter 22

2. 22.1 Early Astronomy I. Early Astronomy
A.__________________________________ – the science that studies the universe.
united streaming
B. ____________________________________________
1. Using basic geometry and trigonometry they measured the sizes and distances of the sun and moon.
2._____________________
concluded the Earth is round because it always casts a curved shadow on the moon when it passes between the sun and the moon
3___________________________
first the establish the size of the Earth using geometry and trigonometry.

3. 22.1 Early Astronomy 4. ____________________________
determined the location of almost 850 stars, measured the length of the year within minutes of modern day, and was able to accurately predict lunar eclipses.
5. ______________________________–
The moon, sun and planets orbit the Earth.
The Earth remained motionless at the center of
the universe.
6_______________________________________– Aristarchus
The Earth and other planets orbit the sun.

4. 22.1 Early Astronomy
7. ______________________________– Claudius Ptolemy
Accounted for the movements of the planets
Used the Geocentric model
Odd movements of planets – if watched night after night, some planets seemed to move backward __________________________________________
Retrograde motion results from both the movements of the Earth and the planets.

5. 22.1 Early Astronomy II. Modern Astronomy
A. ____________________________ -Concluded that the Earth was a planet and that the sun was at the center of the Universe.
B. ______________________– born three years after the death of Copernicus.
Recorded much data, but did not analyze it or make conclusions
Recorded a lot of data about Mars.
In the last year of his life he hired an assistant, __________________________________.

6. 22.1 Early Astronomy
C. _______________________– using Brahe's data along with many years of his own observations, he discovered the ________________________________
1. The path of each planet around the sun is an ellipse. The sun is at one focus, the other focus is symmetrically located at the opposite end of the ellipse.
2. Each planet revolves so that an imaginary line connecting it to the sun sweeps over equal areas in equal time periods. To do this, it must travel more rapidly when it is nearer the sun and more slowly when it is farther from the sun.

7. 22.1 Early Astronomy
3. The square of the length of time it takes a planet to orbit the sun is proportional to the cube of its mean distance to the sun.
__________________________________– the average distance between the sun and the Earth – approximately 150 million kilometers.

8. 22.1 Early Astronomy
D. ____________________________– invented the first telescope
His most important contributions were his descriptions of the behaviors of moving objects.
1. Discovered the four moons of ______________
2. The discovery that the planets are circular disks, not just points of light
3. Discovered that Venus has phases just like the moon.
4. Discovered the Moon’s surface was not smooth
5. Discovered that the sun had sunspots, or dark regions.

9. 22.1 Early Astronomy
E. ________________________– was born in the same year that Galileo died.
1. Proposed the ____________________________.
2. Formulated and tested the _________________________

10. 22.2 The Earth-Moon-Sun System
I. Motions of Earth
A. ___________________ – the turning, or spinning, of a body an its axis.
Gives us day and night
Each rotation takes _________________
_______________________ – time interval from one noon to the next – nearly 24 hours
_____________________ – the time it takes for Earth to make one complete rotation with respect to a star other then the sun
23 hours, 56 minutes, 4 seconds

11. 22.2 The Earth-Moon-Sun System
B. _________________ – the motion of a body, along its orbit around some point in space.
Earth moves 107,000 km/hr
Average distant from sun is 150 million km
The orbit is an ellipse, which means it is closer at some times than at others.
________________ – Earth is closest to sun
Occurs on January 3 each year
_________________– Earth is farthest from sun
Occurs on July 4 each year

12. 22.2 The Earth-Moon-Sun System
The Seasons –
The imaginary line that connects Earth’s orbit with the celestial sphere is the ____________________________________
The __________________is the projection of the Earth’s equator on the sky.
The Earth’s tilt on its axis is __________
When the sun’s apparent position is plotted on the celestial sphere over a period of a year’s time, its path intersects the celestial equator at two points: the spring equinox and the autumn equinox.

13. 22.2 The Earth-Moon-Sun System
At two other times of the year the sun appears 23.5ô north and south of the equator
Summer and winter solstice
C. ____________________________ – the slight movement of Earth’s axis
Over a period of 26,000 years.

14. 22.2 The Earth-Moon-Sun System
II. Earth-Sun motions
A. The entire solar system moves in the direction of the star Nova
B. The Milky Way Galaxy is also in motion – towards to Andromeda Galaxy
C. These speeds are very great.

15. 22.2 The Earth-Moon-Sun System
III. Earth-Moon motions
A. The Earth has one natural satellite – the moon.
B. The Moon orbits the Earth in a period of about one month.
C. It’s motion is counterclockwise around the Earth.
It’s orbit is also elliptical
___________________ – closest to Earth
___________________- farthest from Earth

16. 22.2 The Earth-Moon-Sun System
IV. Phases of the Moon
A. The changes in the amount of the moon that appears lit.
___________– when the moon is between the Earth and the sun – we cannot see the lit portion
It appears like there is no moon at all in the sky
____________– small sliver that approaches the first quarter.
_______________– half circle – right side lit

17. 22.2 The Earth-Moon-Sun System
________________– from first quarter to full moon.
_____________– when the Earth is between the moon and the sun.
we see the whole lit portion of the sun
____________________– moving from full moon the third quarter.
____________________– half circle – left side lit
___________________– from third quarter to new moon.

18. 22.2 The Earth-Moon-Sun System
The moon’s period of rotation and its revolution around the Earth are the same
That is why we see the same side of the moon all the time.

19. 22.2 The Earth-Moon-Sun System
V. Eclipses – shadow effects
A.__________________– when the moon is between the Earth and the sun the moon casts a shadow on the earth.
B. __________________ – when the Earth is between the sun and the moon
C. For an eclipse to take place the moon’s orbit must cross the plane of the ecliptic when in the new or full moon phase.

20. 22.3 Earth’s Moon VI. Moon facts
A. The only natural satellite of the Earth
B. Diameter is ____________________
C. Diameter is ______that of the Earth
D. Our information comes from the ______________________ missions between 1969 and 1972
E. On moon the force of gravity is only _________ that of Earth’s.

21. 22.3 Earth’s Moon VII. The Lunar Surface
A. ________________ – mostly from rapidly moving debris or meteorites
It is heavily cratered
Pg. 631, figure 19
Rays – the material ejected from a crater
Surrounds the crater
B. ______________________ – densely pitted, light colored areas
Mountain ranges

22. 22.3 Earth’s Moon C. _______________ – beds of basaltic lava
Dark, relatively smooth areas
Occurred when asteroids punctured lunar surface allowing lava to “bleed” out.
Rilles – long channels
Ancient lava flows
D. ____________________ – soil-like layer covering the lunar surface

23. 22.3 Earth’s Moon VIII. Lunar History
A. Believed to have been formed when a Mars-sized object struck the Earth, ejecting a huge amount of crust and mantle rock, which eventually formed the moon.
Known as the _______________________
________________________________.