Is astrology scientific? What the tests found, read fairly

Is astrology scientific? Start with its three branches

Varahamihira, writing in Ujjain in the sixth century, says Jyotiṣa consists of three sections, and asks a jyotishi to know “the Horā, the Gaṇita and the Saṃhitā śāstras”. The tradition calls them the three skandhas, and each needs its own answer.

• Gaṇita, whose core texts are the siddhāntas, computes where the Sun, Moon and planets stand and when eclipses fall.
• Saṃhitā reads the sky for the collective. His Brihat Samhita has chapters on rain, earthquakes, comets, prices and omens.
• Horā, or jātaka, reads the birth chart. Varahamihira's works on it also treat marriage and journeys, the ground of kundli milan and muhurta.

The calculation branch is astronomy, and you can check it

Varahamihira told the jyotishi to settle the places of the Sun and planets by actual observation whenever the five astronomical textbooks of his day disagreed. The modern answer is an ephemeris. Every Graha Darpan chart is computed with the Swiss Ephemeris, which its developer, Astrodienst, says is built on NASA JPL's DE431 and DE441 ephemerides and reproduces their data to 0.001 arcseconds.

Try it. For 00:00 UT on 10 October 2026, JPL's Horizons service puts the Moon at a geocentric apparent ecliptic longitude of 188.7250 degrees. A chart cast here for 05:30 IST that day shows the Lahiri ayanāṁśa as 24.2334 degrees and the Moon at Virgo 14°29'30". Take the ayanāṁśa from JPL's figure and you get 164.4916 degrees, which is Virgo 14°29'30". Our engine and JPL agree to a fraction of a second of arc.

The scientific evidence on astrology, test by test

Carlson's double-blind test of natal charts, Nature, 1985

Shawn Carlson, of the physics department at the University of California, Berkeley, reported two double-blind tests in Nature, volume 318. Astrological advisers nominated by the National Council for Geocosmic Research reviewed the design, and Carlson reports that they accepted it as a fair test and predicted at least 50 per cent success.

In the main test, astrologers matched each volunteer's natal chart against three personality profiles from the California Personality Inventory, one of them the owner's. Across 116 charts they put the right profile first 40 times, 34 per cent, against 33 by chance. Volunteers asked to pick their own astrologer-written reading also scored at chance, a result Carlson did not count against astrology, since they could not pick their own personality profile either. He concluded that the experiment “clearly refutes the astrological hypothesis”.

The dispute over Carlson's analysis

In 2009 Suitbert Ertel of the University of Göttingen re-analysed Carlson's figures in the Journal of Scientific Exploration, arguing that the design “violated the demands of fairness” and the analysis was piecemeal. Carlson had planned to test whether the right profile came first or second more often than chance. Counted directly, it did 86 times in 116 against about 77 expected, a marginal result (p = .054), and the astrologers' ten-point ratings pointed the same way (p = .04). Ertel judged this “insufficient to deem astrology as empirically verified” but enough to make Carlson's verdict “untenable”. Neither paper finds the 50 per cent the astrologers predicted.

Jayant Narlikar's test in India, Current Science, 2009

In Maharashtra, Jayant Narlikar of the Inter-University Centre for Astronomy and Astrophysics, Pune, and three colleagues set astrologers a two-way sorting task. Volunteers of the Andhashraddha Nirmulan Samiti collected certified birth details for 200 schoolchildren, 100 recorded by their schools as intellectually bright and 100 from special schools for children with intellectual disabilities. Co-author Prakash Ghatpande, once a practising astrologer, cast the charts, and the code key stayed with Pune University's statistics department.

Each astrologer sorted 40 random charts into the two groups and needed 28 right to beat a coin toss at the 1 per cent level set in advance. Of 51 astrologers sent charts, 27 replied. The best scored 24, and the average was 17.25 against 20 by chance. One astrology institute took all 200 charts and scored 102, short of the 117 required. The authors concluded that astrology showed no predictive power “as far as academic ability is concerned”.

A review of more than forty studies, 2003

In the Journal of Consciousness Studies, Geoffrey Dean and Ivan Kelly's meta-analysis of more than forty controlled studies “suggests that astrologers are unable to perform significantly better than chance”. Among 2,101 people born in London during 3 to 9 March 1958, on average 4.8 minutes apart, 110 measured traits showed “no hint of the similarities predicted by astrology”.

Astrologers, as Dean and Kelly also note, do not agree on how astrology should be tested, or even whether it can be. A practitioner may say a chart is read whole, with the person present. A scientist may answer that a claim no controlled test can reach is not yet a scientific claim.

The scientific consensus, in Britannica's and NASA's words

Encyclopaedia Britannica writes, “Often regarded as a science throughout its history, astrology is widely considered today to be a pseudoscience”, while noting the millions who put their faith in systems including Hindu astrology. NASA's Space Place says astrology “is not the same thing as astronomy”, and adds, “While astrology is important to some cultural traditions, its claims are not based on scientific evidence.” We think both describe the published tests fairly, which is why we offer a reading as reflection, not proof.

Is Vedic astrology scientific, or more scientific than Western?

Jyotiṣa's sidereal zodiac subtracts the ayanāṁśa, about 24 degrees today, so its signs stay anchored to the stars instead of drifting with the precession of Earth's axis, as our comparison of Vedic and Western astrology explains. That makes a Vedic chart's positions astronomically current. It does not make its predictions tested, and in Narlikar's test, run with astrologers in Maharashtra, they scored no better than chance.

Why families still consult a kundli

Science asks whether a chart predicts. Families usually ask other things of it. In many Indian homes a kundli, or kundali, is opened to choose a muhurta for a wedding, and Narlikar's paper itself notes the belief, common in India, that a couple should not marry unless their horoscopes match. Hindu practice offers puja to the navagrahas in temples. A dasha reading can give a hard year a name and an end. This is faith, ritual and reflection, and it deserves description without salesmanship or sneering.

The tradition keeps its own rule of honesty. Varahamihira advises a ruler to reject the astrologer who, “after the occurrence of an event, pretends that his prediction already meant so much”.

How Graha Darpan offers Jyotiṣa

We keep the two layers apart. The arithmetic is exact and shown. Charts use the Swiss Ephemeris, the Lahiri (Chitrapaksha) ayanāṁśa, whole-sign houses and mean nodes, with every position shown to the minute of arc and the settings named. The reading is the tradition's interpretation, offered for reflection, and our AI Jyotishi answers only from your computed positions. We sell no gemstones, poojas or dosha removals, sell nothing through fear and promise no outcome. Health, legal and money decisions belong with a doctor, a lawyer or a financial adviser. Our method sets out the rest.

Common questions

Is astrology scientifically proven?

No. In the best known controlled tests, astrologers matching charts to people scored at or near chance, and Britannica and NASA place astrology outside science. What is exact is the astronomy under a chart, which can be checked against NASA JPL.

What did Carlson's 1985 double-blind test in Nature find?

Astrologers matched natal charts to one of three personality profiles and put the right one first 40 times in 116, or 34 per cent, where chance gives 33 and astrologers had predicted at least 50. Suitbert Ertel's 2009 re-analysis found a marginal effect when first and second choices are combined.

What did Jayant Narlikar's astrology test find?

Astrologers sorted the charts of 100 intellectually bright children and 100 from special schools. The 27 who replied averaged 17.25 correct out of 40, against 20 by chance, and the best scored 24 where 28 was needed. The study appeared in Current Science in 2009.

Is Vedic astrology scientific?

Its calculation is. The gaṇita branch is astronomy, and the sidereal zodiac stays anchored to the stars through the ayanāṁśa. Its predictions are not established. The horā branch is what tests examine, and the Indian test by Narlikar and colleagues found no better than chance.