The Observatory Desk · Daily
Today's sky.
Where the Sun, the Moon and the five bright planets are in the zodiac today — the Moon's phase and how much of it is lit, the sign each of Mercury, Venus, Mars, Jupiter and Saturn is passing through, which of them are retrograde, and when the next new and full moons fall. Every number is worked out in your browser from standard astronomical formulas the moment you open the page, so it is always today's sky, never a page written in advance. Pick another date to see any day from 1900 to 2050.
Reading the sky…
Today's positions are calculated by JavaScript in your browser, and it is switched off here, so the live dial, table and dates are hidden. The sections below still explain what the page shows and exactly how it is calculated; turn JavaScript on to see today's sky.
The Moon Astronomy
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In the sign of —
In astrologyThe Moon is said to colour the mood of the day; its sign changes every two to two and a half days.
The Sun Astronomy
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In astrologyThe Sun's sign is said to set the tone of the month; tradition reads it as the season's theme.
Plate · The Seven Lights
Every sign, today.
The seven classical bodies, all easy to see without a telescope: the zodiac sign each one is in, how far through that sign it has travelled, whether it is moving forward or appears to move backward, and when it next changes sign.
| Body | Sign | Position | Motion | Next sign change |
|---|---|---|---|---|
| Sun | — | — | — | — |
| Moon | — | — | — | — |
| Mercury | — | — | — | — |
| Venus | — | — | — | — |
| Mars | — | — | — | — |
| Jupiter | — | — | — | — |
| Saturn | — | — | — | — |
In astrologyA retrograde period is traditionally read as a time to review and revisit rather than begin — a symbolic reading, not a forecast. The motion itself is an effect of perspective: Earth overtakes, or is overtaken by, the other planet. How retrograde works.
Plate · The Coming Lunations
The next four phases.
The exact moments of the next new moon, first quarter, full moon and last quarter, in your own time zone.
New Moon
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First Quarter
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Full Moon
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Last Quarter
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Plate · Your Chart, Today
What is moving through your signs.
Save your Sun, Moon and rising signs on this device and this page will show which of today's planets are passing through them — read, as astrology reads it, as symbolism rather than prediction.
Save my chart for Today's Sky
Your Sun and Moon signs are worked out exactly as the birth chart does it. Only the three signs are kept, in this browser's storage (my404:astrology:chart); your birth date and time are not stored and nothing is sent anywhere. The birth chart does not calculate rising signs yet, which is why you choose it here.
Your signs
How this reading works. A planet passing through the same sign as your Sun, Moon or rising sign is what astrologers call a transit to that point. Tradition holds that the passing planet lends its themes — Mercury its talk and thought, Saturn its structure and limits — to the part of the chart it touches, and that a planet in the opposite sign works like a mirror.
This page compares signs only, not exact degrees, so it shows the broad weather rather than the fine detail an astrologer would draw. It is a lens for reflection: nothing here is a forecast, and none of it is advice about health, money, relationships or any decision.
Plate · The Method
How the sky is calculated.
Nothing on this page is looked up or downloaded. When it opens, your browser runs a small set of published astronomical formulas for the moment shown — the current minute for today, or midday for any other date — and draws the result.
- The Sun uses the low-accuracy solar method in Jean Meeus, Astronomical Algorithms (2nd edition, 1998), chapter 25.
- The Moon uses the 34 largest terms of the lunar series in Meeus chapter 47; its phase and the lit fraction follow chapter 48. New and full moons are found by searching for the moments the Moon is 0° and 180° from the Sun.
- Mercury, Venus, Mars, Jupiter and Saturn use the orbital elements published by NASA's Jet Propulsion Laboratory, "Keplerian Elements for Approximate Positions of the Major Planets" (E. M. Standish), valid from 1800 to 2050 — the same elements the Orrery uses. Each planet's position is seen from Earth, corrected for the time its light takes to reach us, and shifted from the year-2000 reference frame to the current equinox.
- Retrograde means a planet's longitude, seen from Earth, is decreasing. The page compares its position half a day either side of the moment shown, and searches back and forward for the days it appeared to stand still.
How accurate is it? We checked it against JPL Horizons, NASA's precision ephemeris, on four dates between August 2024 and October 2026: every position came within 0.1° — the Sun and Moon within 0.01° — and the lit fraction of the Moon within half a percentage point. New, full and quarter moon times matched published tables to within about two minutes. Further from the present the simple planet formulas drift more: for some dates in the 1900–2050 range Jupiter and Saturn can be off by up to about 0.2°. A planet within a few hours of changing sign can still show the old sign for a moment, which is why the table gives the exact time of each change.
Which zodiac? Signs here are tropical, as in Western astrology and the Astrarium's birth chart: twelve equal 30° slices counted from the March equinox point. They are not the constellations of the same names, which the equinox has drifted away from over the centuries.
Plate · Two Kinds of Sky
What is measured, and what is read.
Astronomy · measured
Where each body sits along the ecliptic, the Moon's phase and lit fraction, the dates of new and full moons, and which planets appear to move backward. These are facts anyone can check against an almanac or a telescope.
Astrology · read
What a planet in a sign is said to mean. Astrology is a symbolic tradition, not a science; its readings are interpretations people have handed down, and Astrarium presents them that way — as a lens for reflection, never as prediction or advice.
Plate · Straight Answers
Quick answers.
What sign is the Moon in today?
The Moon moves through all twelve signs in about 27.3 days, so it changes sign roughly every two and a quarter days (between about two and two and a half). Today's Sky calculates its position for the moment you open the page and shows the exact time it moves into the next sign.
Is Mercury retrograde right now?
Mercury appears to move backward against the stars three or four times a year, for about three weeks each time. Today's Sky checks every planet's motion for the date shown and lists the dates each retrograde began and ends. Retrograde motion is an effect of viewing the planets from a moving Earth; no planet actually reverses.
Why don't the signs match the constellations?
Western astrology uses the tropical zodiac: twelve equal 30-degree signs counted from the point where the Sun crosses the celestial equator in March. Because Earth's axis slowly wobbles (precession), that point has slid about 28 degrees along the zodiac in the last two thousand years, out of the constellation Aries and into Pisces, so a planet's sign and the constellation behind it often differ. (The tropical and sidereal zodiacs now differ by about 24 degrees.)
For the Moon in more depth, see Moon Phases; for meteor showers and a live Moon, see the Almanac.