Review #5, page 37) If Earth did not rotate, could we define the celestial poles and celestial equator?
The ecliptic? We could not define the terms for the celestial poles or the celestial equator. Since the North and South celestial poles are defined as extensions of Earth’s rotation axis, without rotation, it would not be possible to define these. Since the celestial equator is halfway between the celestial poles, we could not define this either. However, the definition of the ecliptic would not change. This is the apparent path of the sun due to the Earth’s orbit around it. Even if the earth did not rotate, it would still orbit the sun. • (Problem #7, page 37) Identify the phases of the moon if on March 21 the moon were located at (a) the vernal equinox, (b) the autumnal equinox, (c) the summer solstice, (d) the winter solstice. The key point to notice is that March 21 is the vernal equinox. This means the sun will be at a specific point, in relation to the heavens. a) If the moon is also at the vernal equinox, this means the Sun will be behind the moon. The phase of the moon in this
