Mercury
Planet
The messenger — mind, speech, and the famous retrograde.
In the sky right now
Scorpio 19°32′
Ecliptic longitude 229.53°
Currently direct
Daily motion 0.542° per day
Retrograde cycle
- StatusDirect
- Last went directJul 23, 2026
- Next retrograde beginsOct 24, 2026
- Next retrograde endsNov 13, 2026
- Mercury retrogrades three or four times a year, for roughly three weeks each time — more often than any other planet.
Astronomy
- Average distance from the Sun
- 57.9 million km (0.39 AU)
- Orbital period
- 88 Earth days
- Rotation period
- 58.6 Earth days (3:2 resonance with its orbit)
- Solar day
- 176 Earth days — longer than its year
- Diameter
- 4,879 km — the smallest planet
- Moons
- None
- Temperature range
- −180 °C to 430 °C
- Known since
- Antiquity; observed by Babylonian astronomers by the 2nd millennium BCE
Planetary facts follow NASA and JPL reference data. Moon counts reflect IAU-recognised satellites as of August 2026. Zodiacal positions and retrograde stations are calculated live using the app's VSOP87/NOVAS-derived astronomy engine rather than being hard-coded. The lunar nodes shown are True (osculating) nodes, computed from the Moon's instantaneous orbital plane — the same convention Astro.com uses by default.
Greek & Roman mythology
Greek
Hermes
Roman
Mercurius
Hermes was the Greek messenger of the gods, and also the patron of travellers, merchants, orators, boundaries — and thieves. The Homeric Hymn to Hermes has him stealing Apollo's cattle on the day he was born, then inventing the lyre from a tortoise shell and talking his way out of trouble by giving it to Apollo.
He was also psychopomp: the god who guides souls down to the underworld, the only Olympian who moves freely between worlds. That crossing-of-boundaries role is the thread that connects his other jobs.
The Roman Mercurius was originally a god of trade and profit — the name is connected to merx, 'merchandise' — with a temple near the Circus Maximus dedicated in 495 BCE. As Roman writers absorbed Greek myth, Mercurius took on Hermes' biography wholesale.
In a natal chart
Mercury governs thinking, speaking, writing, learning, commerce, short journeys and everything that involves getting information from one place to another.
It never appears more than about 28° from the Sun, so it is always in the same sign as the Sun or one of the two adjacent signs.
Mercury rules both Gemini and Virgo, is exalted in Virgo, in detriment in Sagittarius and Pisces, and in fall in Pisces.
Rules: Gemini and Virgo
See where Mercury falls in your chartExplore the rest of the sky
Don't write your paper based on this page. We keep the facts as accurate as we can, but moon counts get revised, missions rewrite the textbooks, and the live positions are computed on the fly — treat this as a reliable starting point, not a real-time oracle.