Juno Sign
Calculator

Karl Ludwig Harding found Juno on September 1, 1804, at the Lilienthal observatory near Bremen. It was the third asteroid known, after Ceres (1801) and Pallas (1802), and Vesta followed in 1807. It is about 250 km across.

Juno circles the Sun in 4.358 years, on an orbit tilted 12.97° to the ecliptic and stretched enough (eccentricity 0.2584) that its distance from the Sun runs from 1.978 to 3.358 astronomical units. Seen from the Earth it turns retrograde once every 474 days, its synodic period, for between 73 and 114 days at a time. Those figures come from the site's ephemeris, the same source as the calculator.

The steps behind a result. The ephemeris, time zones and orbs are shared with all our tools and described on the methodology page.

1. Birth moment. Your clock time becomes Universal Time through the IANA time zone database.
2. Position. Juno, Ceres, Pallas and Vesta come from our ephemeris as apparent geocentric longitudes, computed the same way as the planets in our birth charts; it covers the four asteroids from 1800 to 2399. Degrees are truncated to the arc-minute, never rounded up into the next sign.
3. Retrograde. A body is marked retrograde when its longitude is decreasing at the birth moment.
4. House. Read from the cusps of the house system you choose. In Whole Sign houses the house is the sign counted from the rising sign; in Placidus and Equal houses it is the space between two cusps, so the true Ascendant decides it. Placidus cannot be drawn beyond about 66.5° of latitude, and the calculator says so instead of guessing.
5. Aspects. Juno's aspects use the orbs of our birth charts: the base orb for each aspect times the average of the two bodies' factors, 0.75 for an asteroid. Juno opposite the Sun may be up to 8° from exact, a Juno–Pallas square only 5.2°.
6. Returns. Juno's longitude is sampled every day from two years after birth to age 100, each day's step split wherever Juno stations, and every crossing of the birth degree is pinned down by bisection to about a tenth of a second. Crossings less than a year apart count as one return.

Because Juno's orbit is eccentric, it does not give the signs equal time. It is nearest the Sun, and moving fastest, in the direction of Taurus (its perihelion lies at about 58° of heliocentric longitude, near the end of Taurus), and slowest on the far side, toward Scorpio. Counting every day from 1900 to 2049, Juno was in each sign this share of the time:

Juno spends almost three times as long in Scorpio (13.0%) as in Gemini (4.6%), so a Juno in Scorpio, Sagittarius or Libra is common and a Juno in Gemini, Taurus or Cancer is not. It moves up to 0.598° a day forward and 0.262° a day backward, and changed sign on only 0.96% of days in the period, retrograde re-entries included. That is why a birth date is nearly always enough for the sign, while the house still needs the time.

Prince William's official birth announcement gives 9:03 PM, June 21, 1982, in London: 20:03 UTC. Juno stood at 2°56′ Capricorn, retrograde, moving back 0.23° a day. It had turned retrograde on April 30, 1982 at 9°56′ Capricorn, and went on to station direct on August 19, 1982 at 24°16′ Sagittarius, back in Sagittarius. Moving forward again, it passed his birth degree on October 16, 1982, 117 days after he was born. That pass closes the loop he was born in and is not a return, which is why the calculator starts looking for returns two years after birth.

Which house?

His Ascendant is 27°28′ Sagittarius. In Whole Sign houses the rising sign, Sagittarius, is the 1st house, so Juno in Capricorn is in the 2nd. In Placidus the 1st house runs from the Ascendant itself to the 2nd cusp at 12°43′ Aquarius, so Juno, 5.5° past the Ascendant, is in the 1st. The same position, two answers: this is why the calculator lets you choose the house system and names it with the result.

Aspects

With the orbs above, Juno makes a sextile to the Midheaven 0.49° from exact, sits 0.61° from the Part of Fortune, and opposes the Moon (2.02°) and the Sun (2.84°), which sit together at the start of Cancer. A reader of the modern school would start from those oppositions. The example sets out the calculation and makes no claim about his marriage.

Ceres, Pallas and Vesta

All four change house between the two systems in his chart. His Ascendant falls late in Sagittarius, and at London's latitude the Placidus houses are very uneven in size, so the two sets of houses sit well apart; Ceres and Pallas move by two houses. The generator script checked every position against an independent offline run of the same ephemeris and every house against the cusps from its own house calculation.

A Juno return is Juno arriving back at its birth degree. It comes about every 4.358 years, but not like clockwork: the Earth's own motion shifts the date, and in 400 sample births between 1900 and 2000 the gap from one return to the next ran from 4.11 to 4.79 years, 4.359 on average. In 15.1% of those returns a retrograde loop straddled the birth degree, so Juno crossed it three times: forward, backward and forward again. Astrologers who use the return read it as a time when Juno's themes (partnership, commitment, the terms of a relationship) come up again.

Prince William has 22 Juno returns before age 100, 5 of them with three passes. The first twelve:

The gaps between his returns run from 4.12 to 4.78 years. Entering his 40th birthday as the date gives the 10th return as the next one, on January 6, 2026 at age 43.5. Every pass in the list was recomputed independently, and a separate scan in six-hour steps found the same 32 passes.

The notes follow the modern reading of Juno by sign, written as tendencies in what a person looks for in a committed partner. The house shows where in life those needs are most often met or tested, and close aspects from the Sun, Moon, Venus or the Descendant weigh as much as the sign.

The house shows the part of life where the commitment Juno describes is lived out, and it is the part of the reading that needs a birth time. Check it in the house system you use: in Prince William's chart the same Juno is in the 1st house in Placidus and the 2nd in Whole Sign.

The calculator places the rest of the first four asteroids with Juno, since modern readings often take them as a set.

• Ceres. Ceres, the Greek Demeter, was the goddess of grain and the harvest. In her best-known myth her daughter Proserpina (Persephone) is carried off to the underworld, Ceres grieves, and the earth stays barren until the daughter returns for part of each year. Astrologers read the asteroid for how a person gives and receives care, and how they cope with loss.
• Pallas. Pallas Athena was born fully armed from the head of Zeus. She was the goddess of wisdom, strategy and crafts, and a war goddess who won by planning rather than force, unlike Mars. Astrologers read the asteroid for practical intelligence, pattern recognition and political skill.
• Vesta. Vesta, the Greek Hestia, was the goddess of the hearth. Her priestesses, the Vestal Virgins, took vows of chastity and kept her fire burning in Rome. Astrologers read the asteroid for what a person devotes themselves to with single-minded focus, and for how work, dedication and sexuality fit together.

For partnership questions the synastry calculator compares two charts, and the Venus–Mars matrix covers the attraction side that Juno leaves to Venus.

• Juno's finding by Karl Ludwig Harding at Lilienthal on September 1, 1804, and its size: the standard astronomical record of asteroid 3 Juno.
• Eleanor Bach, Ephemerides of the Asteroids: Ceres, Pallas, Juno, Vesta, 1900–2000 (1973), the first asteroid ephemeris for astrologers.
• Demetra George with Douglas Bloch, Asteroid Goddesses: The Mythology, Psychology and Astrology of the Re-emerging Feminine (ACS Publications, 1986), the basis of the modern readings.
• Our methodology page: the ephemeris and its date range (1800–2399), time zones and the aspect orbs.