1. Unit E – Space Exploration
Lesson 4-1: (sec 1.1 and 1.2) Early Views About the Cosmos and Discovery through technology

2. A. Tracking the Cosmos looked to the skies to ancient people
predict the coming of summer and winter
marks the
longest day of the year…
summer solstice
June 21 in the Northern Hemisphere
marks the
winter solstice
shortest day of the year…
Dec 21 in the Northern Hemisphere
slide 1 of 7

3. predict the timing of the solstices
many were built to
ancient structures
predict the timing of the solstices
eg) Stonehenge
are
two times in the year when daylight and nighttime are equal in length (March 21 and September 21)
equinoxes
slide 2 of 7

4. B. Planetary Motion objects in the sky are constantly moving
ancient peoples wished to make sense of it all
of planetary movement and star movement emerged
models
slide 3 of 7

5. patterns assigned to groups of stars in the night sky constellations
are
patterns assigned to groups of stars in the night sky
constellations
slide 4 of 7

6. C. Geocentric Model 2000 years ago proposed an Aristotle
Earth-centered (geocentric) model of the universe
sun, moon, Mercury, Venus, Mars, Saturn and Jupiter orbit Earth
early astronomers used this model to but couldn’t explain other
calculate moon phases
celestial events
slide 5 of 7

7. D. Heliocentric Model in suggested a
sun-centered (heliocentric) model of the universe
1530, Copernicus
Earth and the other planets orbit the sun
in the was the first scientist to
1600’s, Galileo
use a telescope
slide 6 of 7

8. studied and recorded the Brahe movement of the planets
later, added orbits to the model
elliptical (oval-shaped)
Kepler
slide 7 of 7

9. Discovery Through Technology
1.2
Discovery Through Technology

10. A. Astronomical Tools were used by Egyptians to merkhets and quadrants
chart the stars
Arabians used
astrolabes and cross-staffs
scientists like Galileo used
telescopes, which contained combinations of different lenses
telescopes are still used to observe objects in space
slide 1 of 3

11. B. Astronomical Units units like are for measuring distance in space
metres and centimetres
too small
is the distance from
astronomical unit (AU)
the center of the Earth to the center of the Sun
1 AU = 149,599,000 km
AU’s are used to describe positions of objects in our solar system
slide 2 of 3

12. C. Light Years in one second, light travels 300,000 km
sunlight takes to reach Earth
8.5 minutes
a is the
distance traveled by light in one year:
light-year
9,500,000,000,000 km = 9.5 trillion km
light-years are used to measure great distances between
stars and galaxies
slide 3 of 3

13. Assignments:
Worksheet 1 and 2 