Astronomy lesson 2 all

3. Lunar Landscape
• Surface of the moon from a telescope light and dark colored
areas with bowl shaped pit are visible on Moon’s surface .
1)Craters
• It has impacts from space objects have formed craters or bowl –
shaped depression

4. • Even though the moon and Earth are hit by space
objects at about the same rate ,the Moon has more
craters .
• Earth’s protective atmosphere causes most of the
incoming objects burn up .

5. 2)Maria
• They are large ,dark flat surface areas on the moon.
• Maria means sea in Latin .
• The smoothness of the maria led people long ago to think
that they might be seas of water .

6. How Maria are formed ?
• Maria formed when huge space objects collide with
the moon’s surface.
• These large areas of impact then filled with lava
,when lava cools it gives the maria their smooth
appearance and dark color

7. 3)Mountains
• They are formed around the edges of large
maria .
• The mountains probably formed from same
impact that formed from the same impact that
caused the maria .

8. 4)Highlands
• They are found near the lunar poles.
• They are higher elevations compared to maria .
• The surfaces of highlands have more craters than
maria do, so scientists believe that the high lands are
geologically older landscape.

9. 5)Valley
They are cigar shaped depressions.
Perhaps the most famous is “Alpine Valley”.
New evidence suggests that the floors of some deep
moon valleys may contain small amounts of ice .

10. Moon phases

11. What causes phases of the
moon?
• The change in the relative position of Earth ,Moon and Sun .

13. It’s Just a Phase
• Moonlight is reflected sunlight
• Half the moon’s surface is
always reflecting light
• From Earth we see different
amounts of the Moon’s lit
surface
• The amount seen is called a
“phase”

14. Waxing and Waning
• New moon
• Waxing Crescent moon
• First Quarter moon
• Waxing Gibbous moon
• Full moon
• Waning Gibbous moon
• Third Quarter moon
• Waning Crescent moon
• New moon
earth
moon orbit`s
earth
last (third)quarter
gibbous moon
full moon
gibbous moon
first quarter
crescent
new moon
crescent
waning Moon
waxing Moon
SUN

15. FULL
QUARTER
CRESCENT
GIBBOUS
FOUR MAIN SHAPES

17. Eclipses
• An eclipse happen when one body in space blocks light from
reaching another body in space .
• There are two types of eclipses :
1) Solar eclipse 2) Lunar eclipse
They occur
when Earth
,Moon and the
Sun line up
It occurs
when the
moon is
always a new
moon
It occurs
when the
moon is
always a
full moon

18. SolarEclipse
• It occurs when the moon makes a shadow on Earth,
and this happens during the “new moon”.
• In some places the moon seems to cover the sun, and
the sky gets dark .
• In other places ,only part of the sun is covered.

20. Lunar Eclipse
• It occurs when the moon passes through the shadow of
the Earth this happens during “full moon”.
• Earth blocks the sun’s light from reaching the moon, but
the moon doesn’t look black, instead it looks red.
• This is because Earth’s atmosphere bends (refracts) red
light, which then reflects off the moon.

21. Refraction of light

22. Tides• The regular rise and fall of water level along a shore is called a “Tide”
• The pull of gravity between Earth and the moon causes tides
.
• The greater the object mass the greater its gravitational pull
• Gravity exists between the Sun and the planets and also
between a planet and its moons .

24. • The pull of gravity changes with distance .
• In case of Earth and moon ,the pull is stronger on the side of
the earth that is facing the moon .
• This causes the Earth’s water to bulge on the moon facing
side of Earth .
• The water level rises where the bulge is and falls where it is
not .
• This causes the regular rise and fall of the tides.

25. • Sometimes ,the way the Sun,Moon and Earth line up causes tides to
be especially strong or weak .
• These tides happens twice a month .
• They depend on the gravitational pull of the moon and the Sun .

26. • When the Sun ,Earth and the moon are in a line ,a spring tide occurs.
• During spring tides ,high tides are higher than usual and low tides are
lower than usual .

27. • If the gravitational pull of the Sun and the Moon are at right
angles ,a neap tide occur.
• During neap tides ,high tides are lower than usual and low
tides are higher than usual .