The New Moon appears close to the sun
Q:
How come a new moon is always close to the sun?
A:
To answer this question, let's first consider the phases of the Moon. The Moon goes through phases because it revolves around the Earth in nearly the same
plane as the Earth orbits the Sun. The Moon always casts a shadow over half of its body. We see sometimes more of the Moon and sometimes less depending
on our viewing angle of the bright half. Our angle changes constantly through the lunar month as the Moon revolves about Earth. We call these changing
shadow and light patterns, the phases of the Moon.
I step outside with a tennis ball to visualize Moon phases. The Sun is almost setting when I face the Sun and hold the ball up to the Sun's low rays. I pretend
I'm the Earth and my outstretched arm with the tennis ball is the Moon orbiting Earth. I turn slowly all the way around and watch my tennis ball orbit me and
see the phases of the "moon" occur as the Sun casts shadows on my tennis ball.
My complete turn represents one lunar month.
First, I stand facing the Sun with the tennis ball in my outstretched hand.
Since I'm facing the Sun, my ball is totally in shadow. It is a New Moon.
I turn a quarter
turn counterclockwise and look at the ball. I now stand with my side to the Sun
and half the ball is in the light. It is a First Quarter Moon.
I turn another quarter turn and now the Sun's behind me. The Sun, the tennis ball and I form a straight line. My whole tennis ball faces the Sun and shines
brightly with no shadow. It is a Full Moon.
Another quarter turn and my left side faces the Sun. I'm now three-quarters the way around from where I started. Half of the tennis ball shines and half is in
shadow. It is a Last Quarter Moon.
Finally, I turn a quarter turn more and I'm back to where I started, facing the Sun with the tennis ball between me and the Sun. This is New Moon; the Sun and
Moon are lined up on the same straight line and the night side of the Moon faces Earth. When the Moon is New, the dark Moon and the bright Sun travel together through our
sky and the Moon's shadow hides it from Earth dwellers.
To answer your question about the New Moon: A New Moon always appears to be close to the Sun because all three bodies are on the same straight line in this
order: Sun, Moon, and Earth. We on Earth have to see the New Moon (except it's too dark to see
against the brilliant Sun) at the same time we see the Sun because it's
on our
line of sight to the Sun. When we can see the almost-new moon, i.e., the Crescent Moon, it is almost on our line of sight to the Sun and, therefore, seems to be
nearby the Sun.
(Answered by April Holladay, science correspondent, June 13, 2001)
Further Surfing:
University of Wisconsin phases of the moon animation. Set the point of
view to 'both'. Start the animation by clicking 'animate'. Then
click the 'stop' button now and then (followed by clicking 'animate') to see how
the phase of the moon changes with the position of the moon in orbit around
Earth. It's neat.
U.S. Naval Observatory (USNO):
Moon phase Images
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