From a vantage point on Earth, the sun and moon share the same celestial longitude, a projection of the Earth's own longitude lines on the celestial sphere. This alignment is also called a ...

But the basic principles behind celestial navigation are fairly straightforward ... This means that if the sun is above the longitude of 0 degrees at noon, one hour later it will be above 15 ...

More formally, a new moon is when the sun and moon share the same celestial longitude, a projection of the Earth's longitude lines on the sky. This is also known as a conjunction. The time of a ...