IC lines in astrocartography: Imum Coeli lines
An IC line, short for Imum Coeli (Latin for the bottom of the sky), marks the places where a planet was directly underfoot, on the far side of the Earth, at the moment you were born. Astrologers read it as the line of home, family, roots and private life.
By Lucas Pradella · Updated 18 October 2026
What is an IC line in astrocartography?
An IC line, also called an Imum Coeli line or nadir line, marks the meridian where a planet was at its lowest point, beneath your feet, when you were born. It runs straight from pole to pole. Astrologers read it as the most private line type, tied to home, family, roots and inner life.
About twelve hours after a planet culminates, it reaches its lowest point, crossing the meridian beneath the horizon. At your birth, each planet was at that lowest point for one meridian of the Earth. You could not have seen it there: it was on the other side of the planet, below your feet.
An IC line is the exact opposite of the same planet's MC line, 180 degrees of longitude away. Like the MC line it runs straight from pole to pole and has the same longitude at every latitude. On our map IC lines are dashed straight lines in the planet's color.
What astrologers associate with the IC line
In a birth chart the IC is the cusp of the fourth house: home, family, parents, ancestry, property and the private self that few people see. It is the foundation of the chart, the place you retreat to and recharge.
Because the planet was hidden below the horizon, tradition reads IC lines as felt inwardly rather than shown to the world. Their effects are described as quiet and gradual: a sense of belonging, or unrest, that grows over months rather than days. Some people notice an IC line near a family's place of origin and read it as a link to roots. That is an interpretation, not a pattern anyone has measured.
The IC line, planet by planet
Each link opens the full page for that line.
| Line | Often described as |
|---|---|
| Sun IC line | A quiet sense of self; a base to build, family stories |
| Moon IC line | One of the most domestic lines: nesting, memory, belonging |
| Mercury IC line | A busy household; study at home, long family talks |
| Venus IC line | A comfortable, pleasant home and family harmony |
| Mars IC line | Energy at home: renovating, defending, clearing the air |
| Jupiter IC line | A generous base; a roomy house and a welcoming family |
| Saturn IC line | Serious work on foundations; a home that becomes secure slowly |
| Uranus IC line | An unsettled base; frequent moves, freedom at home |
| Neptune IC line | A dreamy retreat; near water perhaps, hard to pin down |
| Pluto IC line | Digging into roots; rebuilding private life from the ground up |
| North Node IC line | Purpose found through home, ancestry and family history |
| Chiron IC line | A private place to make peace with old family hurts |
Home and daily life
This is the heart of the IC line. When people ask where to put down roots, they usually look here first. A Moon or Venus IC line is read as a place to nest, a Jupiter IC line as room to spread out. A Saturn IC line is not a reason to stay away: it is described as a place where a home is built slowly and holds.
Practical matters come first in any move. A line says nothing about property prices, schools, safety or visas, and it is not advice to buy, sell or relocate.
Love and work
In love, IC lines are read through living together, family life and settling down rather than first dates. At work, they point to the private side of a career: working from home, a family business, writing, research or anything done behind the scenes. Public standing belongs to the opposite MC line.
Strengths and challenges
Strengths
- Associated with belonging, rest and a stable base.
- Good for private projects and inner work.
- Its quiet tone suits long stays.
Challenges
- Can stir up family memories and old patterns.
- Less visible, so its effects are easy to misread.
- Harder planets here are read as unrest at home before calm.
Visiting versus living near an IC line
A visit to an IC line is often described as feeling at home somewhere you did not expect, or as missing home more than usual. Living there is where tradition says the line comes into its own, because the IC is about the place you return to every night.
How close you need to be
No distance is agreed; many astrologers give most weight to a few hundred kilometers on either side. The map gives the exact distance from any city, and best places for home lists the IC and other home lines near you.
Which IC line is best for home?
The Moon, Venus and Jupiter IC lines are the ones astrologers most often describe as comfortable for a home base. The right line depends on what you want from home: quiet, space, family, or a project to rebuild, which a Saturn or Mars IC line is read as suiting. Practical needs come first.
Is an IC line weaker because the planet is below the horizon?
Astrologers treat all four angles as strong. The IC line is described as private rather than weak: its effects are read in your inner life, home and family, where others see them less. That is also why IC lines are usually said to show over months of living somewhere more than on a short visit.
Why is it called Imum Coeli?
Imum Coeli is Latin for the bottom of the sky, the opposite of Medium Coeli (MC), the middle of the sky. It is the point where a planet crosses the meridian beneath your feet, out of sight on the far side of the Earth. Some astrologers also call it the nadir, and an IC line a nadir line.
Should I buy a home on my IC line?
A line is a symbolic reading, not property or financial advice. Astrologers use IC lines as one input when thinking about where to settle, next to cost, work, schools, family and everything else that makes a place livable. The map says nothing about a particular property; surveys, prices and your own finances decide that.