The birth chart is a photo of the sky when you were born. It doesn't move. The sky does. A transit is what happens when a planet in today's sky makes an aspect to a planet in your birth chart, and it's the main way astrology answers "when."
This guide covers what a transit is, which planets matter for what timescale, how to read a transit by aspect and by house, the three passes that outer planets make, and how to find the transits that are actually running your year.
What a transit is
Take your birth chart. Now take the positions of the planets right now and lay them around the outside of the wheel. Wherever a current planet lands on, or makes an angle to, a planet or angle in your chart, that's a transit.
Transiting Saturn conjunct your natal Sun: Saturn is now sitting where your Sun was at birth. Transiting Jupiter square your natal Moon: Jupiter is 90 degrees from your Moon. The outer planet (the transiting one) is the event; the natal planet is the part of you it's happening to.
Transits are the only predictive technique that uses the real sky. Everything else (progressions, solar arcs, returns) is derived. That's why astrologers start here.
Fast, medium, and slow transits
A transit lasts as long as the planet takes to move through its orb, usually a degree or two on each side of exact.
Fast transits (Moon, Sun, Mercury, Venus, Mars): hours to a couple of weeks. They color the day or the week. The Moon crosses your entire chart every month; you'll notice its transits mainly through mood. Mars transits last a few days and bring energy or friction to whatever they touch.
Medium transits (Jupiter, Saturn): weeks to months. Jupiter takes about a year per sign, so a Jupiter transit to a natal planet lasts a few weeks per pass, and the whole episode (three passes) can span most of a year. Saturn spends two and a half years in a sign; a Saturn transit to a planet is typically a nine-month to one-year affair.
Slow transits (Uranus, Neptune, Pluto): a year to three years. These are the transits that mark chapters of a life. Pluto crossing your Sun happens once, lasts up to three years, and you don't come out the same.
Rule of thumb: the slower the transiting planet, the bigger and rarer the event. Read the slow transits first; they set the context for everything else.
Transit by aspect
- Conjunction: the transiting planet merges with the natal one. Strongest, most direct. Saturn conjunct Sun: a test of who you are. Jupiter conjunct Venus: love and pleasure expand.
- Opposition: external confrontation. The theme arrives through other people or circumstances that push back. Uranus opposite Sun: something outside forces a change you'd been avoiding.
- Square: friction and pressure. The most productive hard transit; things get done under a square because standing still isn't an option.
- Trine: ease, flow, opportunity that's easy to miss because it doesn't announce itself. Jupiter trine Sun: a good period that you may only recognize in hindsight.
- Sextile: a small opening. Useful if you act.
Hard transits (conjunction, square, opposition) make events. Soft transits (trine, sextile) make conditions. Most of the stories people tell about "the year everything changed" trace to a hard transit from Saturn, Uranus, Neptune, or Pluto.
Transit by house
A transiting planet is also moving through your houses. Its house tells you where the theme is showing up.
Saturn moving through your 10th house (two and a half years): career is under review; you'll be tested and, if you pass, promoted. Jupiter through the 7th (a year): partnership expands, a new relationship or a deepening. Uranus through the 4th (seven years): home and family go through upheaval and reinvention.
Transits through houses are slower and more general than transits to planets. The transit to a planet is the event; the house transit is the season.
The three passes
Outer planets go retrograde, which means most of their transits happen three times: direct, then retrograde, then direct again. A Saturn square to your Moon might be exact in March, again (retrograde) in July, and a final time in December.
The three passes have a rhythm. First pass: the issue appears. Second: you revisit and often go deeper. Third: resolution. If a transit feels like it's dragging on, check whether you're between passes. If it's the third pass, you're nearly done.
Some transits get only one pass (the planet doesn't retrograde over that degree), and those tend to be sharper and shorter.
The transits everyone gets
Because the outer planets move at predictable speeds, some transits arrive at roughly the same age for everyone:
- Saturn return (29, 58, 87): Saturn back to its natal position. Adulthood, then elderhood.
- Jupiter return (12, 24, 36, 48, 60): a fresh cycle of growth every 12 years.
- Uranus opposition (about 42): the midlife transit. Restlessness, reinvention, the urge to break something.
- Neptune square Neptune (about 41): meaning dissolves and re-forms.
- Pluto square Pluto (varies, 36 to 60 depending on generation): power and mortality become real.
- Chiron return (about 50): the old wound resurfaces to be made peace with.
- Nodal return (18.6, 37, 56): re-alignment with the life direction.
These are the skeleton of a life. The transits to your personal planets put the flesh on it.
Reading a transit: a worked example
Transiting Saturn conjunct natal Venus in the 7th house.
- Planet: Saturn. Limits, tests, structure, time.
- Aspect: conjunction. Direct, strong.
- Natal planet: Venus. Love, pleasure, values, money.
- House: 7th. Partnership.
- Duration: about nine months across three passes.
Reading: a partnership is tested. Either it becomes serious (commitment, marriage, moving in) or it ends because it can't bear the weight. Pleasure is rationed; money may be tight. Someone older or more serious may enter. Afterwards, whatever remains is durable.
That's the whole method: planet, aspect, natal planet, house, duration. The rest is knowing the person.
What transits can't do
They can't tell you what will happen, only what kind of thing and when. Saturn on Venus is a test of love; whether it's a wedding or a divorce depends on the relationship going in.
They're also weak on their own for anything house-based if the birth time is unknown, because the houses depend on the time. Transits to planets still work.
And a transit with nothing else supporting it (no solar return echo, no progression, no profection lord involved) tends to be quieter than the textbooks suggest. Astrologers stack techniques for a reason.
See your transits
Open the transit tool โ, enter your birth details and a date. The tool shows the current sky around your birth chart, lists every transit with orb, applying or separating, and the natal house it lands in, and lets you move the date to see when each transit is exact.
Start with the slow planets. Find where Saturn, Uranus, Neptune, and Pluto are in your houses right now and whether any is within two degrees of a natal planet. That's your year. The Moon and Mercury are your week.