An apsis (Greek: ἁψίς; plural apsides /ˈæpsᵻdiːz/, Greek: ἁψίδες) is an extreme point in an object's orbit. The word comes via Latin from Greek and is cognate with apse. For elliptic orbits about a larger body, there are two apsides, named with the prefixes peri- (from περί (peri), meaning "near") and ap-, or apo- (from ἀπ(ό) (ap(ó)), meaning "away from") added to a reference to the thing being orbited.
A straight line connecting the pericenter and apocenter is the line of apsides. This is the major axis of the ellipse, its greatest diameter. For a two-body system the center of mass of the system lies on this line at one of the two foci of the ellipse. When one body is sufficiently larger than the other it may be taken to be at this focus. However whether or not this is the case, both bodies are in similar elliptical orbits each having one focus at the system's center of mass, with their respective lines of apsides being of length inversely proportional to their masses. Historically, in geocentric systems, apsides were measured from the center of the Earth. However, in the case of the Moon, the center of mass of the Earth–Moon system, or Earth–Moon barycenter, as the common focus of both the Moon's and Earth's orbits about each other, is about 74% of the way from Earth's center to its surface.
A man is walking alone
A woman cries at home
They could be anyone
Without each other, how
Could they live through all of the lies?
Intentions don't provide
So cling to those who you love
The only answer
Stay close and live as one
Through rain and darkened skies
You have the love you need
For all tomorrow's lies
They tell you try to have hope
And fight for all you can
These words, you've heard them before
So easy to believe
Stay close and live as one
Through rain and darkened skies
You have the love you need
For all tomorrow's lies
Stay close and live as one
Through rain and darkened skies
You have the love you need
For all tomorrow's lies
A man is walking alone
A woman cries at home
They could be anyone
The only answer
Stay close and live as one
Through rain and darkened skies
You have the love you need
For all tomorrow's lies
Stay close and live as one
Through rain and darkened skies
You have the love you need
For all tomorrow's lies
For all tomorrow's lies
For all tomorrow's lies
For all tomorrow's lies
For all tomorrow's lies