The Moon is Earth's only natural satellite. It is the fifth largest moon in the solar system and has been explored by numerous spacecraft. The Moon moderates Earth's axial wobble and causes ocean tides, both of which influence the planet's climate. Its surface is dominated by impact craters and basaltic plains called maria that formed from ancient lava flows. The Moon has no significant atmosphere and its gravity is much weaker than Earth's.

1. Luna –
Earth’s Moon
Presented by,
Anandwardhan

2. Luna - Earth’s Moon
• The fifth largest moon in the solar system, Earth's Moon is
the only place beyond Earth where humans have set foot.
The Moon is the most explored body in our solar system
besides Earth, having been visited by numerous spacecraft
from multiple space agencies around the world.
• The brightest and largest object in our night sky, the moon
makes Earth a more liveable planet by moderating our
home planet's wobble on its axis, leading to a relatively
stable climate. It also causes tides, creating a rhythm that
has guided humans for thousands of years.
• Earth's only natural satellite is simply called "the Moon"
because people didn't know other moons existed until
Galileo Galilei discovered four moons orbiting Jupiter in
1610.

3. The Moon
Equatorial Radius 1,737.5 km
Polar Radius 1,736.0 km
Mass 7.342x1022 kg
Mean Density 3.344 g/cm3
Surface Gravity 1.62 m/s2
Temperature Range -248 to 123o C
Distance from Earth(avg.)
Perigee
Apogee
384,400 km
362,600 km
405,400 km
Orbital period 27 d 7 h 43 min
Synodic period 29 d 12 h 44 min
Near Side
North Pole
Far Side
South Pole
Water found as ICE
(discovered by
Chandrayaaan-1)

4. Formation of the Moon
Early Theories
Currently Acceptable Theory- “Giant Impact Theory”

5. Lunar Atmosphere
• The moon has a very thin and weak atmosphere, called an
exosphere. It does not provide any protection from high
energy solar particles, cosmic rays or impacts from
meteoroids.
• escape velocity is too low on the Moon
• - all gas molecules can escape!
• no atmospheric pressure means that water can not exist
in liquid form
• - only in solid or vapour
• no weathering of the surface by water, storm

6. Lunar Geological Features
1. Craters
With too sparse an atmosphere to impede
impacts, a steady rain of asteroids,
meteoroids and comets strikes the surface of
the moon, leaving numerous craters behind.
Tycho Crater is more than 52 miles (85
kilometres) wide. The craters themselves,
which have been preserved for billions of
years, provide an impact history for the moon
and other bodies in the inner solar system.
2. Regolith
Over billions of years, impacts have ground up the
surface of the moon into fragments ranging
from huge boulders to powder.
Nearly the entire moon is covered by a rubble pile
of charcoal-gray, powdery dust and rocky
debris called the lunar regolith. Beneath is a
region of fractured bedrock referred to as the
megaregolith.

7. Lunar Geological Features
3. Lunar Highlands or Terra
The light areas of the moon are known as the highlands.
Most of moon (85%) is actually covered with lighter, higher
land: Highlands
Rich in calcium and aluminium silicates
Less dense than mare rocks and considerable older(4-4.4
billion years)
Predominantly on the side of the Moon facing away from
Earth
4. Lunar “Maria” (sing.-Mare)- dark, smooth regions
The dark features, called Maria (Latin for seas), are impact
basins that were filled with lava between 4.2 and 1.2
billion years ago.
Relatively ‘low’ compared to highlands on moon; 2-5 km
below other parts .
Made of Basalt, rich in iron, magnesium and titanium
silicates

8. Inner Structure of the Moon
• iron-rich core like Earth
• asthenosphere layer: somewhat pliable “plastic” layer
• solid layer just below surface – no plate tectonics
• smaller planet than Earth – less internal energy, less geological activity!
• crust is thicker on non-Earth facing side
• moon probably had a weak magnetic field early in history
• - core is now solid, so no current is generated

9. Phases of Moon and Tides

10. Orbit of the Moon

11. Solar & Lunar Eclipse
• Penumbral lunar eclipse—the Moon only passes through the penumbra of
Earth’s shadow
• Partial lunar eclipse—part of the Moon passes through the umbra of Earth’s
shadow
• Total lunar eclipse—the entire Moon passes through the umbra of Earth’s
shadow
• Annular solar eclipse—When the Moon is too far to completely cover the
Sun—the umbra doesn’t reach the Earth
• Partial solar eclipse—Those in “penumbra” see a partial eclipse—not safe to
look directly at Sun
• Total solar eclipse—Observers in the “umbra” shadow see a total eclipse
(safe to view the Sun); can see the corona

12. THANK
YOU