When the sun, earth , and moon are in these positions, what phase of the moon do we observe?

First Quarter: When the Earth-Moon line is

90

o

away from the Earth-Sun line, it is the First Quarter phase. On those days Moon rises (approximately)

6

hours after the Sun rise and exactly one quarter of the Moon's surface is visible from Earth.

[3] Full Moon: Moon, Earth and Sun lined up with the Earth coming between the Moon and the Sun. But usually the alignment is not perfect with the Moon's longitude lying a little above or below the Sun's longitude. The Earth-Moon line and the Earth-Sun line are close to

180

o

away. However, occasionally the alignment could be near perfect leading to an eclipsing of Moon by the Earth. That is Lunar Eclipse . Not every Full Moon is a Lunar Eclipse but every Full Moon coincides with a Full Moon. On Full Moon days Moon rises just as the Sun sets.

[4] Third Quarter: When the Earth-Moon line is

270

o

away from the Earth-Sun line, it is the Third Quarter phase. On these days Moon rises (approximately) 18 hours after the Sun rise or (approximately)

6

hours after the Sun set and again exactly one quarter of the Moon's surface is visible from Earth.

Explanation:

halogen, any of the six nonmetallic elements that constitute group 17 (group viia) of the periodic table. the halogen elements are fluorine (f), chlorine (cl), bromine (br), iodine (i), astatine (at), and tennessine (ts).