☄ Free Comets in Your Chart Calculator: 21 Comets
Umbriel puts 21 comets on your birth chart, one by one or in groups, with their houses, retrograde marks and aspects.
4420+ people cast their chart here in the last 30 days.
Positions come from JPL’s own orbit solutions. Free.
MODERNA modern technique: twentieth-century astrology.
- What you'll needBirth date, time and place
- What you getWhere 21 comets stood at your birth, with house, ecliptic latitude, retrograde mark and aspects to your planets, your chart points and each other
- CostFree, no account required
What it is
Comets are not part of the traditional canon. For most of history they were read as omens, signs in the sky for a king or a city, and not placed in a birth chart. Umbriel includes them because they are real bodies with real positions, and because they are worth looking at. It does not pretend there is an old tradition of reading them that there is not.
The 21 are a mix. Four are numbered periodic comets that keep coming back (Halley, Pons-Brooks, Holmes and Churyumov-Gerasimenko). Sixteen are comets seen on a single apparition, among them Ikeya-Seki, Kohoutek, Hale-Bopp, Hyakutake, McNaught, NEOWISE and Tsuchinshan-ATLAS. One, Oumuamua, is the first visitor from another star that anyone has tracked. You can put all 21 on the wheel, a group of them, or just the ones you choose.
A comet can sit far above or below the path the planets follow, so each one is given with its ecliptic latitude as well as its sign, and the retrograde mark is shown where the comet was moving backward at your birth. Aspects are listed in three tables: comets against your planets, against your chart points (the Ascendant and Midheaven, the nodes, Chiron, Fortune and the rest), and against each other. The tables start with conjunctions only, because 21 bodies make a very long list of every aspect, and one tap shows them all.
Be honest with yourself about the arithmetic. With 21 bodies on the wheel, some comet will usually be close to something in your chart, and that is a property of having a lot of points, not a sign about you. A contact is more interesting when you picked the comet first, perhaps one that was in the sky on a day that mattered to you, than when you scanned all 21 for anything that landed.
The same rooms that hold the rest of a natal chart are on the page, so you can read the comets against the planets, houses and balance of your own chart without leaving it.
How Umbriel computes it
Each comet’s position is computed on your device from JPL’s own orbit solutions. Because a comet’s orbit is bent by every close pass of a planet, one set of orbital elements cannot serve for a century, so Umbriel carries a fresh set for each comet every five years from 1900 to 2100 and works from the nearest. A comet that will never return (one on a hyperbolic path) is propagated from its closest approach rather than from a period it does not have. The results were checked against JPL’s ephemeris service across 124 years. Longitudes are moved into the zodiac your chart uses, so a sidereal chart is not quietly given tropical comets. Aspects use the same orbs as the rest of the chart.
What's in your result
- All 21 on your wheelDrawn on your real natal chart, with your planets, Chiron, nodes, Fortune, Vertex and angles.
- In groups or one by oneComets that return, comets that come once, the one from another star, or any single comet by name.
- Position, latitude and houseSign and degree, how far above or below the ecliptic, the house it falls in, and a retrograde mark.
- Three aspect tablesAgainst your planets, your chart points and each other; conjunctions first, every aspect on one tap.
- The usual chart underneathPlanets and points, houses, the balance, midpoints, declinations and the chart’s shape.
Common questions
Are comets used in astrology?
Not traditionally. They were read as omens, not placed in birth charts. Some modern astrologers do look at them, and Umbriel includes them as real positions you can look at, without claiming an old tradition behind them.
Which comets does Umbriel include?
Twenty-one: Halley, Pons-Brooks, Holmes, Churyumov-Gerasimenko, Oumuamua, Ikeya-Seki, Bennett, Kohoutek, West, IRAS-Araki-Alcock, Hale-Bopp, Hyakutake, NEAT, McNaught, PanSTARRS, Lovejoy, NEOWISE, Tsuchinshan-ATLAS, Atlas, Lemmon and Swan.
How accurate are the comet positions?
They are computed from JPL’s own orbit solutions, with a fresh set of elements for each comet every five years from 1900 to 2100, and were checked against JPL’s ephemeris service across 124 years.
Why does a comet have a latitude?
Comets can travel well above or below the plane the planets orbit in, so a sign and degree alone would hide where they really were. Umbriel gives the ecliptic latitude beside the position.
What does a retrograde comet mean?
That it appeared to move backward against the zodiac at the moment you were born, as the planets do from time to time. Umbriel marks it and does not claim a settled meaning for it.
Can I add just one comet to my chart?
Yes. Tap a comet’s name to take it on or off the wheel, or add a whole group at once. Clear the chart takes them all off and Undo puts them back.
Do I need a birth time for comets?
For the sign, usually not, since comets move slowly. For the house and the angles, yes, in exactly the way the planets need one.
Do I need an account or an email address?
No. There is no sign-up, no email capture and no free trial. Enter your details and the result is drawn in your own browser.
Go deeper
Each of these is a free tool in its own right.
Umbriel offers every system here as a set of prompts to think with, never as a statement of fact about who you are. Take what's useful, leave the rest.