Phases of the Moon and Planets Lab

GoudeauAST115-Lab03_Report01

Goudeau, Philip

Purpose:

The Moon is a common astronomical object that we often see. Yet little thought is given to its motion in the sky. In this lab, the phases of the Moon are to be examined, and used to understand its motion in the sky. Visual experiments will be done, with a small ball to represent the Moon and a light source (lamp) representing the sun.

Part 1:

A bright light was shone in a constant direction. Figure 1 was used in conjunction with pictures that were taken in order to represent the different phases of the Moon during the course of its orbit around the sun.

Findings:

For a solar eclipse to occur, the moon must be in the New Moon phase.

For a lunar eclipse to occur, the moon must be in the Full Moon phase.

Part 2

A diagram was used to estimate the the location of the Moon in the night sky based on its progress through its phases

Findings:

The Moon will rise at noon if it is in the third phase.

The Moon will rise at sunset if it is in the fifth phase.

The Moon will be on the meridian at sunrise if it is in the seventh phase.

The Moon will set at midnight if it is in the third phase.

The Moon will be on the meridian at noon if it is in the first phase

The Moon will set at sunrise if it is in the fifth phase

Part 3:

An identifying spot was located on the ball. The spot was monitored and its position recorded. This was done to discover and to better understand the difference between the dark side of the moon and the hidden side of the moon.

Two different procedures were used. One displayed a rotation of the moon with respect to the sun, while the other displayed a rotation of the moon with respect to the earth.

Findings:

The second procedure showed the rotation of the moon with respect to the sun

The first procedure however accurately depicts the rotation of the moon.

The hidden side of the moon is not the same as the dark side of the moon. The hidden side of the moon is the side of the moon that we on earth never see due to the fact of our rotations. While the dark side of the moon is whatever side of the moon that does not receive direct light from the sun. To further prove this, there are times during the moon’s phases where the dark side and the hidden side are completely opposite each other e.g. during the new moon phase, the “hidden” side of the moon is the side that is receiving direct sunlight while the non hidden side is dark, but in view.

Part 4:

Figure 2 was used in conjunction with observations  of planetary phases with perspective from the point of view of the Earth. This procedure was completed twice, one to represent the inferior planets, and the other to represent the superior planets with respect to Earth’s position in the solar system.

Findings:

Inferior planets and Superior planets have the same phases however from the point of view of the earth the planets reach these phases at opposing times.  For example, while one of the superior may appear to be in it’s fifth position with respect to the earth, it is really in its first position with respect to the sun. This pattern repeats itself throughout the different planet’s rotations around the sun.

A superior planet will appear its brightest to us during its fifth phase. This is the planetary phase where the planets’ direct sunlight reflections would be facing the earth.

Part 5:

End of lab questions:

A Lunar or Solar eclipse would not occur every New and Full Moon because the Earth, Moon, and Sun do not lie on the same plane. If this were true an eclipse would appear every new and full Moon.

The difference in the Moon’s orbit of the Earth is different than the occurrence of a full moon because the Earth also rotates, rather than be stationary. Which causes a slight difference in the matching up of these two events.

If you were in a spaceship following the Earth-Moon system (not orbiting) you would not see the same side of the moon every time, because the moon rotates.

If Venus was in between earth and the sun via an Earth centered universe diagram, venus would never have a fifth (full) phase.

Superior planets are visible at midnight

The inferior planets are Mercury and Venus.

The superior planets are Mars, Jupiter, Saturn, Neptune, Uranus and not Pluto.

Three things that were learned during lab:

Planets have phases.

We can observe those phases.

Superior planets are visible at midnight.

The point of this lab was to understand the phases of the planetary bodies in the sky and to put in perspective what all can/cannot be seen from earth.