Combustion (Asta): The Chart Check Almost Nobody Runs

Most chart readouts tell you the sign a planet is in. Combustion needs the degree, so most readouts never mention it. That is a problem, because a combust planet is one the classical texts consider unable to deliver freely, and in a money chart the two planets most often affected are the two you would least want dimmed.

What combustion is

Asta means set, as in a star that has set and is no longer visible. A planet within a certain number of degrees of the Sun is lost in its glare, and classical practice reads that loss of visibility as a loss of independent function. The Sun is not harmed. The other planet is.

The image the texts use is a courtier standing too close to the king: still present, no longer able to act on his own account.

The orbs

Planet	Combust within	Retrograde
Moon	12 degrees	-
Mars	17 degrees	17
Mercury	14 degrees	12
Jupiter	11 degrees	11
Venus	10 degrees	8
Saturn	15 degrees	15

These orbs vary between classical authorities, sometimes by several degrees. Treat a planet just inside the boundary as borderline rather than as a definite ruling, and read the rest of the chart before concluding anything.

Why Mercury is combust so often

This is geometry, not misfortune. Mercury is the innermost planet, and from Earth it never appears more than about 28 degrees from the Sun. The combustion orb is 14 degrees, or 12 when retrograde.

So roughly half of Mercury's entire possible range from the Sun sits inside the combustion boundary. A very large share of all charts therefore have a combust Mercury, and almost nobody is told, because it requires a subtraction their chart printout never performs.

Venus has the same issue less severely: it never exceeds about 47 degrees of elongation, against a 10-degree orb.

What the tradition says it does

The general reading is that a combust planet's significations are still promised and are harder to realise independently. More usefully, the texts describe it as the planet's agenda being subordinated to the Sun's - to ego, position and self-image.

Combust planet	Classical financial reading
Mercury	The most common and the most consequential for money. Calculation, contracts and commerce bend toward what the self already wants to be true. Conviction outrunning verification. See Mercury and financial intelligence.
Jupiter	The one classical texts flag hardest in a wealth reading, since Guru is the natural karaka of wealth and of judgement. Counsel is harder to hear and easier to override.
Venus	Difficulty with the valuation of things and with relationships that carry money. Comfort and taste subordinated to status.
Moon	Combust near the new moon, which is also the weakest paksha bala. The tradition treats this as the hardest Moon to read confidently.
Mars	Initiative expressed as ego rather than as action. Disputes taken personally.
Saturn	Structure and patience undermined by the need to be seen. Long-horizon plans abandoned for visible ones.

The distinction people miss: combustion is not the same as conjunction

A planet in the same sign as the Sun is not necessarily combust. The Sun at 2 degrees of Leo and Mercury at 27 degrees of Leo are 25 degrees apart, in the same sign, and Mercury is not combust.

Conversely, the Sun at 29 degrees of Leo and Mercury at 3 degrees of Virgo are 4 degrees apart across a sign boundary, in different signs, and Mercury is deeply combust.

Combustion is a degree relationship, not a sign relationship. Any reading that decides it from the sign alone will be wrong in both directions, and that is the single most common error made with this condition.

Cancellation and mitigation

Classical practice recognises several conditions that soften a combustion:

• The planet is in its own sign or exalted. Dignity gives it a base to work from even while dimmed.
• The planet is retrograde. Retrogression increases chesta bala, motional strength, which partly offsets the loss. Some authorities hold that a retrograde planet resists combustion specifically.
• Wide separation within the orb. A planet at 13 degrees from the Sun with a 14-degree orb is technically combust and barely so.
• A strong dispositor. The lord of the sign the combust planet occupies can carry some of the load.

Planetary war, briefly

A related and separate condition worth knowing. When two planets other than the Sun and Moon come within one degree of each other, classical texts describe a graha yuddha or planetary war, and the one further north or brighter is said to win. The loser is treated as weakened, in some ways similarly to combustion. Our engine reports it, and it is far rarer than combustion.

How to check yours in one subtraction

1. Generate your free birth chart, which reports exact longitudes rather than only signs.
2. Note the Sun's longitude in degrees.
3. For each other planet, take the absolute difference. If it exceeds 180, subtract from 360.
4. Compare against the orb table above.

Do Mercury and Jupiter first. They are the two that matter most for a money reading and, in Mercury's case, the most likely to be affected. Then read the results against the planets that influence wealth and which houses control money.

One caution on precision: because this is a degree comparison, it depends on your birth time. We measured how much a chart moves with the clock, and a borderline combustion can flip either way on a few minutes. See does birth time matter.

The standing limit

Combustion is a well-defined classical condition and it is not a market signal. Our own backtests across nine assets, two holding periods and more than forty indicator and composite strategies, corrected for multiple testing, return indistinguishable from luck on every one. Method on the technology page.

Frequently asked questions

What does it mean if a planet is combust?

That it sits too close to the Sun to be visible, and classical practice reads that as an inability to deliver its significations independently. The texts describe the planet's agenda as subordinated to the Sun's, meaning to ego, position and self-image. The Sun itself is unaffected.

How do I know if my Mercury is combust?

Take the difference in longitude between your Sun and Mercury. If it is 14 degrees or less, or 12 or less when Mercury is retrograde, Mercury is combust. You need exact degrees for this, not signs, which is why most chart printouts never tell you.

Why is combust Mercury so common?

Because Mercury never appears more than about 28 degrees from the Sun as seen from Earth, and the combustion orb is 14 degrees. Roughly half its entire possible range falls inside the boundary, so a large share of charts carry a combust Mercury purely as a matter of orbital geometry.

Is a planet in the same sign as the Sun always combust?

No, and this is the most common error with the condition. Combustion is a degree relationship. A planet can share the Sun's sign at 25 degrees distance and not be combust, or sit in the next sign 4 degrees away and be deeply combust.

Can combustion be cancelled?

It can be softened. Classical mitigations include the planet being in its own sign or exalted, being retrograde, which raises its motional strength, sitting near the outer edge of the orb, or having a strong dispositor. None of these remove the condition; they change how much it matters.

Does combustion affect my finances?

The classical reading for a combust Mercury or Jupiter is a genuine caution about judgement and verification, and it is a statement about temperament rather than about outcomes. Our own testing finds no predictive power in astrological indicators once corrected for multiple testing, and we are not SEBI-registered.

Important disclaimer

Educational and awareness purposes only - not investment advice and not a recommendation to buy or sell any security or commodity. AstroCapitalX is not a SEBI-registered investment adviser. Markets carry risk; please consult a SEBI-registered adviser before investing.