Bottom of the Sky
The Bottom of the Sky (IC) is the lowest point of the chart, opposite the Midheaven: it represents home, origins, and the private root, and it begins house 4.
The Imum Coeli—“the lowest part of the sky”—is the degree of the ecliptic passing below your meridian at the moment of birth: the place the Sun passes through at midnight. It is the point opposite the Midheaven, always 180° away.
It is the most private part of the chart. If the MC is what can be seen from far away, the IC is what is never seen from outside.
What the Bottom of the Sky describes
Home and land: the physical house, immovable property, the place where roots go down.
Origins: the family, the lineage, where you come from. And in Hellenistic doctrine, the father—although modern astrology usually reads it as the mother.
And a domain that comes as a surprise: the end of things. The ancients read in the IC how matters conclude and what of them stays buried.
The MC – IC axis
It is the vertical axis of the chart: the root and the crown. The private and the public, where you come from and where you are heading. And since the IC is the MC minus 180°, it inherits the same caveat: in whole-sign houses it can fall in house 3, 4, or 5, and is read as a sensitive point.
It works like a seesaw: energy given to one end is taken from the other. A good part of the big decisions of a life—moving or staying, putting family or career first—are played out in that division.
Frequently asked questions
What is the IC in a natal chart?
The IC, or Imum Coeli, is the lowest point of the chart, opposite the Midheaven: the place the Sun passes through at midnight. It represents home, origins, and the most private part of life, and in quadrant systems it begins house 4.
Is the Bottom of the Sky the father or the mother?
In the Hellenistic tradition it is read primarily as the father, with the mother in house 10. Much of modern astrology reversed that assignment, so it is worth stating which criterion is in use.
Why is the IC associated with the end of life?
Because it is the floor of the daily cycle: the lowest point the Sun reaches before climbing again. The ancients read there how matters end and what of them remains.