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Planetary Basics - MERCURY


"The Light of the Messenger" Mercury in Astrology represents the mind: thoughts, ideas, general consciousness/awareness, communication, language, learning style and basic education, Commerce and Trade, Exchange of goods or information, and Day to Day Travel. As Mercury travels through the signs of the zodiac wheel, it influences our state of mind, our focus, our communication, and what we are interested in or curious about. Mercury in any particular sign can show us how ideas and goods are being shared or moved around in the collective. Each person will individually have the influence of Mercury in their natal chart but will also feel and be influenced by the current movements of Mercury.

Mercury Key Concepts:

  • Thought, reason, logic, problem solving

  • education, learning style, intellectual interests, and memory

  • Communication and Language. Written and spoken words.

  • Trade, Commerce, and exchange. The movement of goods or ideas from one to another.

Mercury Key Words: Agility, Awareness, Barter, Brain-Power, Communication, Connection, Commerce, Cunning, Dexterity, Exchange, Expressiveness, Ideas, Information, Intellect, Intelligence, Knowledge, Learning, Learning Style, Logic, Memory, Messages, Messenger, Mental Faculties, Mind, Mindfulness, Perception, Problem-Solving, Rationality, Speech, Thinking, Thoughts, Trade, Travel, Trickster, Wit, Writing, Youthfulness

Mercury's Condition in a Chart: Domicile / Rulership in Gemini or Virgo Exalted in Virgo Detriment in Sagittarius or Pisces

Fallen in Pisces Rejoices in the 1st House Nocturnal/Diurnal (Both, flexible)

Mercury is not considered to be Nocturnal or Diurnal (a Night or Day planet) - but is both and either - depending on the sign it is in and whether it is an evening star or a morning star in the birth chart. While some planets are considered to be either Nocturnal and strong in a night chart, or Diurnal and strong in a Day Chart, Mercury is flexible and can find strength in either a Day or Night Chart. In this same way, Mercury is not considered to be either Projective (Masculine) or Receptive (Feminine) but it is a planet considered to be Nonbinary or Gender-Neutral!

Mercury-ruled occupations: Postal Work, Delivery, Messengers. Writers, Authors and Editors. Public Speakers. All Teachers - but especially Elementary School teachers, Language Teachers. Clerks, Cashiers, Secretaries, Accountants, Merchants and Shopkeepers. (just a few examples but Mercury occupations are not limited to this list)

Mercury-ruled physiology and anatomy: The nervous system and the various functions of the nerves are ruled by Mercury. Thyroid glands, vocal cords, bronchial tubes, lungs and respiration. Hands, Dexterity, and reflexes. Sight and Hearing - or the general ways in which we receive information. Mercury governs the human child's age of 5 to 14 - the period of a youthful and curious mind.

Deities associated with the planet Mercury: Greek: Hermes - messenger of the gods, fleet-footed (swift) traveler, and a psychopomp (able to travel to and from the Underworld). Great orator, speaker, and teacher. God of Travel, Commerce, Messages, Thieves, Trickery, Knowledge, Language, Astrology and more. Roman: Mercurius/Mercury - same attributes as Hermes

Egypt: Thoth - God of Language, Books, and Knowledge

Hindu: Hanuman - Monkey-God of Wisdom and great feats, son of the Wind God for whom travel to all places is possible. Norse: Odin - The All Father who is the most wise, keeper of knowledge and the great teacher of the runes (language, writing)

Buddha - a title for one who has been enlightened by divine wisdom

(not a complete list)

Frequent Combustion - Tied to The Sun

A Combustion relates to the nature of any planet coming into close conjunction with the sun. The sun's bright rays outshine the planet - the planet becomes invisible to us. The planet is considered "burned" or "scorched" by coming too close to the sun - it cannot share a throne and therefore the combust planet loses influence. A planet is considered Combust when it is within 18° of either side of the sun. (Though some consider the combustion to only count when it is within 10 or 12 degrees of the sun - but generally a planet will be invisible unless it is more than 18° away from the Sun)

While Mercury is Combust, the "job" of Mercury (Communication, Commerce, Trade, Travel, Critical Thinking & Problem Solving) becomes a job that is shared by the Sun; some would say that all of the realm of Mercury's job is now appropriated by the Sun. Mercury is no longer a separate entity with its own agency to rule the mind - The Sun now rules both the heart and the mind.

Most planets come into combustion just once a year, but Mercury is in combustion range multiple times a year, spending more than half of its time in close proximity to the sun. For this reason, some astrologers might argue that Combustion isn't a detrimental point for Mercury; "It's not a bug, it's a feature". While others say that it is a detriment, and that Mercury just frequently loses its autonomy and yields to the sun on a regular basis. Either way, you can see that Mercury and the Sun have a unique relationship. Mercury and Sun are intertwined and deeply connected - Mercury will never be more than 28 degrees away from the Sun in the zodiac wheel. 18 of those 28 degrees are in combustion range, leaving only 10 degrees where Mercury escapes combustion and is a visible star, seen only right after sunset or just before sunrise.

Mercury's elusive nature - sometimes visible and then disappearing for weeks at a time before re-appearing are what earned this star its reputation as a traveler, a messenger of the gods, a psychopomp, and a trickster. At one point it was believed by the Ancient Greeks that the star that sometimes appeared at night was a different star than the one sometimes seen in early mornings; they called the morning star Apollo as it preceded the rising sun, while the evening star was named Mercury. Eventually they realized this was the same star - but being mistaken for Apollo seems to align with Mercury's close relationship with the Sun and how the sun often shares the traits of Mercury. The Sun in astrology symbolizes our vitality, our self-expression, and sense of identity - and these concepts of selfhood and awareness are deeply connected to our mind and our thoughts. "I think, therefore I am" - if the Sun is "I AM" and Mercury is "I THINK" - then these two parts of selfhood and consciousness are intrinsically tied together. It is also worth noting that gaining new knowledge is also referred to as "shining a light on something", and attaining great knowledge is called "enlightenment". The Sun is often attributed to Alertness, Awareness, and Awakening - and those are also things that we attribute to brain activity and thought processes. Could one even be capable of self-awareness without having thoughts and some level of intellect?

For all of these reasons, I would encourage interpretation of Mercury to be synthesized with interpretation of the Sun - rather than seeing them as two separate entities to interpret individually, notice how together they make two parts of Human Consciousness and our general sense of self awareness and self-identity.

Mercury Retrograde

Another unique trait of Mercury is that it has three retrograde periods per year. (These take place while Mercury is Combust - though sometimes Mercury can be combust while it is not in retrograde)

Mercury Retrograde is a time of REview, RElapse, REst, REalign, REpurpose, ReVisit, and Re-Do. Mercury appears to travel backwards through the part of the zodiac that it already moved through. (Yes, this is an optical illusion as planets do not reverse direction and move backwards, but astrology relates to the apparent motion of planets from our perspective here on earth, which is also in motion - so sometimes the planets appear to go backwards and then forward again) In general, during a Mercury Retrograde we tend to notice the realms of communication, trade, travel, and technology can get a little bumpy and chaotic. Things don't go as smoothly as we had hoped, and there are delays, mishaps, communication failures, etc. Again, if we think of Mercury's Combustion as a time when the Sun is taking on the Duties of Mercury, we can see how some problems may arise. The Sun may have good intentions - it leads with the heart and through sheer willpower. But how many times in life have you made choices with good intentions based only on your heart or your will and things just didn't quite turnout right? With Mercury we analyze and dissect, we use discernment or logic to calculate the right movement, speed, velocity. With Mercury Retrograde, the planet is appearing to move backwards and then, *poof* - disappears and hands the reins over to The Sun with a sly wink. That Trickster!!

Remember - Mercury Retrograde doesn't create problems - it points out existing problems so they can be dealt with. The planets are like teachers, and when we engage with Astrology, we are opening ourselves up to the teachings and lessons of the planets. Mercury is the teacher of all things related to our minds, thoughts, and communication. Travel, commerce and trade are included in Mercury's realm because the process of moving goods or people from one place to another is something that involves thought and communication. When we speak, we are moving our thoughts from inside our head, into another person's head. When we sell or trade goods, we are moving a product from one person's possession to another person's possession. When we travel, we are moving our physical bodies from one place to another place. And when we use technology such as computers and phones or automobiles, we are using tools that have been designed to help with communication, trade, or travel.

When Mercury goes retrograde - there is a tendency for these things to malfunction. It is like a teacher giving us a pop quiz to see if we were paying attention. Do you know how to deal with travel delays when your guide goes missing? Do you know how to deal with communication issues when your language teacher / translator is taking a vacation? Do you know how to analyze and organize information in the classroom even if the teacher is not there?

It is easy to take on a victim mindset around Mercury Retrograde - "oh why is this happening to me?" - but I find it much more rewarding to take a different approach. When things are going wrong - think of this as an opportunity to learn. Travel Delays? Maybe you need to slow down, pay attention, take a different route, or remember to enjoy the journey. Communication issues? Maybe your communication skills need an upgrade, and you needed a reminder to listen more, ask more questions to clarify things, stop making assumptions, and speak your mind or share your truth. Technology issues? Maybe this is a reminder to be less dependent on technology, or to be more grateful for our technology and remember to take care of it instead of taking it for granted.


I hope you have enjoyed this post all about the Astrology of Mercury! I am hoping this can serve as a helpful tool or guide for your studies.

Additional Resources:

The Astrology Podcast - Mercury in Astrology

Cameron Allen EA Zoom - Mercury Retrograde


If you would like a personal astrology chart reading, please feel free to email me at to schedule your session! Check out my current special offers - I have a Mercury Retrograde Reading special available for December of 2022!


NEWS - I am honored to announce that I will be the VESSEL OF HERMES for Spring Mysteries Festival, 2023!

Come join us April 6 - 9 for a weekend of ritual exploration of Greek Mythology use code HERMES10 for 10% off your registration fee!


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