2. After going through this module, you are
expected to:
1. explain what is astronomy;
2. enumerate the examples of astronomical
phenomena;
3. describe the phases of the moon;
4. differentiate lunar and solar eclipses;
5. appreciate the importance of
astronomical phenomena and how they
affect your life.
3. Astronomy Defined
Astronomy is the science of the universe
outside of our planet.
This is the branch of physical science
dealing with heavenly bodies.
It has resulted in many practical inventions,
ideas, including calendars,
navigational techniques, laws of motion,
engineering of products and an increased
understanding of energy and weather.
4. Some Astronomical Terms for Students
Moon: A natural object that orbits a larger object.
Eclipse: when one celestial body such as a
moon or planet moves into the shadow
of another celestial body.
Solar eclipse: a type of eclipse that occurs
when the Moon passes between the Sun
and Earth, and the Moon fully or partially blocks
the light from the Sun.
Lunar Phase: one of the cyclically recurring
apparent forms of the moon
5. Gibbous: the figure of the moon that is more
than half full, looking swollen on one side
Crescent: the figure of the moon that
appears as a curve with pointy ends
Waxing: growing; describes the moon when
the illuminated portion is increasing
Waning: shrinking; describes the moon
when the illuminated portion is decreasing
Planet: In the solar system, a planet is a
large round object that orbits the Sun and
has cleared out most of the other objects in
its orbit.
Solar System: The Sun and all of the
planets, comets, etc. that revolve around it.
6. Even before the advent of the telescopes,
ancient astronomers were able to observe
the following:
1. rising and setting of the Sun in the east and
the west, respectively,
2. point where the Sun rises and sets in the
horizon varies in a year,
3. phases of the moon,
4. lunar eclipse,
5. solar eclipse,
6. daily and annual motion of the stars, and
7. planets Mercury, Venus, Mars, Jupiter, and
Saturn.
7. 1. Rising and Setting of the Sun
Babylonian and Egyptian civilizations used
a primitive version of a sundial, called
gnomon, in systematically observing the
motion of the sun.
By looking at the shadows that the
gnomon casts, they were able to observe
that the sun rises in the eastern part of
the sky, reaches its highest point in
midday, and sets in the western part of
the sky.
8.
9. these variations happen periodically.
They observed that these variations are
related to weather and so concluded that
seasonal changes in climate happen
during a course of one year.
2. point where the Sun rises and
sets in the horizon varies in a year,
11. A moon, also called a satellite,
is a relatively small object that is orbiting
around a planet.
Earth’s moon is the fifth biggest moon in
the solar system
On average, the distance between the
Earth and the moon is 384,000 kilometres.
the moon is about four times smaller than
the width of the Earth.
16. The lining up of the earth, moon, and sun
produces a lunar eclipse when the moon
passes into the shadow of the earth.
Usually a lunar eclipse either precedes or
follows a solar eclipse by two weeks. Just as
all solar eclipses involve a new moon,
all lunar eclipses involve a full moon.
A lunar eclipse may be partial or total.
All observers on the dark side of the earth
see a lunar eclipse at the same time.
Interestingly, when the moon is fully
eclipsed, it is still visible and reddish.
17.
18. solar eclipse
A solar eclipse occurs when the moon’s
shadow falls on the earth. Because of the
large size of the sun, rays of sunlight taper to
provide an umbra and a surrounding
penumbra.
An observer in the umbra part of the shadow
experiences darkness during the day
a total eclipse, totality. Totality begins when
the sun disappears behind the moon
and ends when the sun appears on the other
edge of the moon. The average time of
totality is 2 to 3 minutes, and a maximum of
7.5 minutes.
