22. Think. Pair. Share.
There are 4 practical reasons why humans have
been fascinated with (and studied) space for
thousands of years. What are they?
23. 1) Navigation
Measurements between stars in the sky allow explorers
to determine their location and direction by using a
sextant and a nautical almanac (reference book)
24. 2) Religion
Due to its size and difficulty of exploration, some people
believe it to be the home of God(s). Others believe
the universe was created by God(s).
Ra, Neptune,
Egyptian Roman
God of God of
the Sun the Sea
25. 3) Weather
The passage of time was tracked using celestial bodies
such as the sun and the moon. Ancient civilizations
built calendars which counted days and years.
Stonehenge
Mayan Calendar
26. 4) Agriculture
By tracking time using a calendar, we can predict how
long a plant may take to grow or when the seasons
will change.
27.
28.
29. The constant movement of celestial bodies
(the collective term for the planets, asteroids,
and stars) has provided us information for:
• Time of day
• Weather
• Tides
• Planting and
harvesting seasons
• Navigation
30. Models of Celestial Motion
Earth-Centred Model: Geocentric Model
• It was believed that the earth was the centre
of the universe (everything revolved around
the earth).
• This view lasted 2000 years.
31.
32. Sun-Centred Model: Heliocentric Model
• Some celestial motions could be better
explained if Earth was not in the center. It
made more sense if a sun-centred model for
the solar system was used.
• This is the present model.
33.
34. How do we Know this is True?
People observed:
• The Moon phases and times of moon rise
• The Sun time and position of rising and
setting
• The Stars rotations around Polaris (North
Star)
• The Planets Greek word for "wanderer"
36. Think. Pair. Share.
i) What are the names of the 8 planets in the Sol
Solar System?
(Hint: E J M M N S U V)
ii) Order the planets according to their distance
from the Sun.
iii) How can you remember this order?
37. The Planets
A Planet:
• Orbits a star, but is not a star itself.
• Is spherical.
• Is the biggest object in its orbital path.
38. The Planets
Inner planets
• Mercury, Venus, Earth, and Mars.
• Also called the terrestrial planets.
• Relatively small, have solid cores and rocky crusts.
39. The Planets
Outer planets
• Jupiter, Saturn, Uranus, and Neptune.
• Also called the gas giants.
• Large clumps of gas, ice and dust, cold temperatures.
40. Asteroid Belts
Asteroids are chunks of rock and metal floating in space.
There are 2 asteroid belts in our solar system:
1) Between Mars and Jupiter.
2) The Kuiper Belt (pronounced “kyper”) on the edge of
the solar system – (20 times wider, about 100 times larger
than the asteroid belt)
41.
42. Pluto
Pluto is not a planet.
In 2006 Pluto was declared to be
a dwarf planet because:
a) It sometimes crosses Neptune’s orbit.
b) Does not have a clear orbit (other objects in its
path).
c) Other objects in the Kuiper were discovered to be
larger than Pluto.
43. Dwarf Planets
Dwarf planets orbit the Sun and are spherical, but are
not the largest objects in their orbits.
- Pluto
- Makemake
- Haumea
- Eris
- Ceres (not in Kuiper Belt)
Editor's Notes
http://www.youtube.com/watch?v=4PN5JJDh78I (Carl Sagan – Pale Blue Dot)Hubble 7:57-13:15 and 34:25-end
http://www.youtube.com/watch?v=2pfwY2TNehw (Carl Sagan – Pale Blue Dot)
Halley’s comet (pronounced Hawley’s) appears visible from the naked eyeevery 75-76 years. The next time it will be visible from earth without a telescope is in July of 2061.
http://www.youtube.com/watch?v=oF-8llc6dWo (Pyramids and Orion’s belt)http://www.youtube.com/watch?v=bYQA2_6N0GU (short image showing correlation)ORhttp://www.youtube.com/watch?v=aBPJ1bSdgOA (short Google maps image showing correlation)
