Umbriel University: the free lessons

A real, sequenced astrology course. These 32 lessons are free to read here in full — the astronomy under the astrology, how a birth chart is actually calculated, and how to read one. No account, no email.

32 free lessons · about 31,000 words · every one also runs on your own chart inside Umbriel

Astronomy for Astrologers

The sky itself: the ecliptic, the tilt, the clocks and where the numbers come from. Open in any order — Module 1 never waits for it.

1. The line everything is measured alongSay what the ecliptic is, why every planet is found within a narrow band of it, and why a chart describes a planet with one number rather than three.
2. The tilt, the seasons, and why 0° Aries is a momentDerive the four cardinal points of the zodiac from the Earth's axial tilt, and explain what that same tilt sets a hard ceiling on.
3. Precession: why the signs left the constellationsExplain the wobble that moved the equinox, put a number on the drift, and answer the most common objection to astrology accurately rather than defensively.
4. Two clocks, and why the Ascendant moves a degree every four minutesDistinguish the solar day from the sidereal day, and use the resulting rate to say honestly how much of a chart an uncertain birth time actually puts in doubt.
5. Orbits and speeds: where the timescales come fromRead a planet's orbital period as the length of the chapter it writes, and tell a sidereal period from a synodic one.
6. The Moon's orbit: phases, nodes and eclipsesDerive the lunar phases as an aspect, explain why the nodes move backwards, and say exactly what an eclipse needs that an ordinary New Moon does not.
7. Where a planet actually is: three frames and one originTell the ecliptic, equatorial and horizon frames apart, and say which astrological claims live in which — including the one your houses are built in.
8. Where the numbers come fromSay what an ephemeris is, what a modern one actually contains, and name the four things that make a beautifully precise chart wrong.
9. Time is the hard partWalk a birth time from a hospital clock to the timescale the planets are computed in, and name the three questions to ask of any recorded time.
10. What you could actually have seenRead the Sun's glare as a measurable zone, tell a morning star from an evening star off the chart, and explain why half the traditional condition rules are visibility claims.

Casting a Chart

From a birth certificate to a wheel, by hand and by engine — and what a house system actually does.

1. From a birth certificate to a wheelName the five steps between three pieces of birth data and a finished chart, and say which input controls which part of the result.
2. The Ascendant and Midheaven, builtSay what each angle is a crossing of, explain why they are not 90° apart, and use signs of long and short ascension to predict which Rising signs are common.
3. What a house system actually doesSay what each family of house systems divides and by what, and explain what does and does not change when you switch between them.
4. Why house systems disagree, and where they breakPredict how much two house systems will differ for a given chart, name the latitudes where some systems fail outright, and choose one for a reason you can state.
5. Casting a chart by hand, onceInterpolate a planet's position from a daily ephemeris and assemble a chart without software, then check your work against the engine.
6. How to tell a chart is wrongRun four checks that catch most bad charts in ten seconds, and recognise the one common error that no check can catch.

The Cosmic Map

Signs, elements, planets & glyphs: the alphabet.

1. What a birth chart isExplain exactly what a natal chart is a picture of, why date, time and place each change it, and what kind of claim astrology is making.
2. The twelve signsName the twelve signs in order, say where the ring actually starts and why, and use a sign as an adverb rather than a label.
3. Elements & modalitiesDerive all twelve signs from four elements and three modalities, and read what happens when your own chart is heavy or empty in one of them.
4. The planets & their glyphsRecognise every glyph, and explain why a planet means what it means rather than memorising a list of keywords.
5. Retrograde planets (℞)Explain why retrograde motion happens at all, read ℞ in a chart, and tell a natal retrograde apart from the transit everyone complains about.

The Framework

Houses and the angles, where life happens.

1. The twelve housesExplain houses as the arenas of life, say where they come from astronomically, and read an empty house without inventing anything.
2. The angles: Ascendant, MC, and why time mattersDefine all four angles, read them as two axes rather than four points, and judge how much of a chart survives an uncertain birth time.
3. Rulership & the chart rulerFind your chart ruler, follow a rulership from one house to another, and read a house that has no planet in it.

The Conversations

Aspects: how the planets talk to each other.

1. Aspects: how planets talkIdentify the five major aspects and describe the quality of each.
2. Aspect patterns & the bigger pictureRecognise a stellium, T-square and grand trine, and read repeated themes.
3. Chart shapes & emphasisRead the overall shape of a chart and spot where the emphasis falls.

Reading a Chart

Method & synthesis: putting it all together.

1. The lunar nodes: your growth axisExplain the South and North Nodes as a past-comfort / growth-direction axis.
2. Your Big Three: Sun, Moon, RisingExplain the roles of Sun, Moon and Rising and why to start there.
3. A method for reading any chartApply a repeatable step-by-step method to approach an unfamiliar chart.
4. A full worked reading, step by stepWatch the five-step method applied to a whole chart, from blank wheel to a few clear themes.
5. Practise, practise, practiseCommit to reading real charts, and know how to use the Practice drills.

What is behind Membership

These are the free lessons and they are complete: nothing has been cut out of them. The course continues past them with 67 further lessons — timing and prediction, dignity and sect, relationship work, the traditional toolkit, the schools of thought, and the professional track — and those are part of Umbriel Membership. What Membership buys is the writing and the advanced material; anything the engine works out stays free, which is why every chart, every calculation and every lesson above costs nothing.

Elsewhere on Umbriel

“University” is Umbriel’s name for a real, sequenced course, not an accredited academic institution. Anything you earn here is Umbriel’s own record of course completion, recognised by us — not a licence, a diploma or a government-accredited qualification. Astrology is offered for reflection and enjoyment, not as a regulated profession.