In astrology, Mercury is the messenger planet, the communicator. When we listen, talk, share ideas, gossip and set the world to rights, each of us has a different way of expressing ourselves. Expression in this way is a very human trait and astrologically speaking, our communicative desires are ruled by Mercury.

What Does Mercury Symbolize in Astrology?

Mercury’s energy is highly intellectual, so this planet governs our thought processes – how logical we might be, how analytical or how imaginative is determined by the sign and house placement of Mercury in the astrology chart. Your Mercury sign also influences communication style, so someone who is a flamboyant, assertive communicator probably has a very different astrological Mercury to someone who communicates in a more low-key manner. Mercury energy is fast-moving and quick-thinking as a general rule, but when poorly aspected this planet can also be responsible for nervous tension and anxiety. Because it is the messenger planet, Mercury also has strong associations with travel.

What is the Importance of Mercury in the Birth Chart?

Because of Mercury’s associations with the intellect, we look to the Mercury sign and house to discover where your intellectual abilities may best flourish. In a child, Mercury’s placement gives us insight into learning style and educational potential – it can also clue us in on emotional intelligence too. Your Mercury sign also suggests how you can best get your message across, whether you’re applying for a job, chatting up a date or writing a research proposal. We all have our own thinking styles, be they careful, logical, innovative or intuitive; understanding your own mental attitudes, through your astrological Mercury, can help you to adapt where necessary and to maximize your strengths.

How Did Mercury Get Its Name?

In astrology, many planets are named for ancient gods. Mercury is the Roman equivalent god to Hermes, the Greek god of trade, language and travel. Hermes and Mercury were both considered the messengers of the gods, which is how this planet came to be astrologically associated with communication. Because Mercury orbits the Sun faster than any other planet, it fits well with the reputation of this speedy Roman god.

How Long Does Mercury Stay in a Sun Sign?

On average, Mercury spends approximately 30 days in each Sun sign. However, this is highly variable, due to Mercury’s retrograde motion (see below). Mercury can spend between 15 and 60 days in a single zodiac sign at certain periods. Due to its astronomical orbit, Mercury is never more than 28 degrees from the Sun – this means that Mercury will always be either in the same sign as the Sun or in the sign before or after the Sun. For example, when the Sun is in Cancer, Mercury must be in either Gemini, Cancer or Leo.

What is Mercury Retrograde?

When we say a planet is retrograde, we mean that it appears to be moving backwards. It’s important to understand that planets never actually move backwards; they move in a continual orbit around the Sun. However, as seen from earth, planets sometimes appear to stop moving forwards, stand still and then move backwards for a while before starting forwards again. This means that Mercury sometimes appears to move from one zodiac sign into the one before it, before coming back again and moving on. This is an optical illusion, similar to how a car you have overtaken appears to be falling behind, even though it is still moving forwards. All of the planets have retrograde motion from time to time, although Mercury retrograde is the best known.

What Does Mercury Retrograde Mean in Astrology?

Mercury turns retrograde three times a year, for about three weeks each time. Because this planet rules our mental processes, thoughts and communication, we tend to notice misunderstandings, mix-ups, confusion and chaos at these times. Mercury retrograde gets negative press and it can be a frustrating time, but its’s also a positive moment for reflection. During Mercury retrograde, pay attention to how you best think according to your Mercury sign. Take time out to review your year so far and to re-think your goals and your attitudes. If you find yourself struggling a great deal during a Mercury retrograde period, this can be a sign that Mercury is particularly strong in your chart.

Key Facts about Mercury in Astrology

Positive expressions of Mercury energy: logic, intellect, curiosity, good communication, lively attitude, laughter, sociable, quick-thinking, versatile, flexible, agile
Challenging expressions of Mercury energy: impulsiveness, difficulty communicating, trickery or deception, slickness, nervous tension,
Mercury rules: Gemini and Virgo. A ruling planet in its own sign tends to be the purest and most positive expression of its energies.
Mercury is exalted in: Virgo. An exalted planet is usually strong and works positively.
Mercury is in detriment in: Sagittarius. A planet in detriment is typically quite weak, with its energy manifesting negatively or being misused.
Mercury is in fall in: Pisces. A planet in fall is usually weakened, although positive aspects to the planet will help.

What’s Your Mercury Sign?

You were born with Mercury in one of the twelve zodiac signs. Where this planet lies in your natal chart is an important factor in your overall astrology.

Mercury in Aries

With Sun in Pisces: Positive, decisive outlook, very good at communicating feelings, very creative and with the confidence to express that creativity.
With Sun in Aries: Very fast thinking, lots of impulsiveness, very little patience. Can be selfish due to not thinking about how impulsive actions will affect others.
With Sun in Taurus: Realistic but enthusiastic. Enterprising and with a skill for business. Makes careful plans but can act quickly and decisively once all information is available.

Mercury in Taurus

With Sun in Aries: Plenty of common sense, less prone to risk-taking than might otherwise be the case. Stubbornness can be a problem, especially if combined with selfishness.
With Sun in Taurus: Very reliable, strong dislike of change. Does not speak or act in haste but likes to thoroughly know and understand a topic before acting. Very stubborn.
With Sun in Gemini: Constructive, positive thinker, with practical abilities. Tones down some of Gemini’s impulsiveness and adds stability and a sense of purpose.

Mercury in Gemini

With Sun in Taurus: Enjoys routine but understands how to handle change when necessary. Blends an appreciation of the status quo and the past with a desire to move forwards.
With Sun in Gemini: Talkative, versatile, charming. Slow to trust own intuition. Can be overly superficial and fickle and would benefit from thinking more thoroughly.
With Sun in Cancer: Frequent changes of mind, indecisiveness, but strong analytical skills and a business sense. Excellent memory, able to rationalize fears and worries.

Mercury in Cancer

With Sun in Gemini: Able to blend logic and intuition well, getting the best of both worlds. Writing and language skills and a strong ability to judge people and to read situations.
With Sun in Cancer: Worries a great deal and can be pessimistic at times. Emotionally moody with a strong attraction to the past. Makes excellent instinctive and intuitive decisions.
With Sun in Leo: Adds empathy to Leo bossiness and common sense to Leo’s impulsiveness. Easy, fluent expression of feelings, and a good ability to look on the bright side of life.

Mercury in Leo

With Sun in Cancer: Highly organized and tenacious, with excellent long-term planning abilities. Sentimental about the past, very loving and creative towards family.
With Sun in Leo: Very optimistic and enthusiastic with a real can-do approach to life. Strong leadership and a flair for the dramatic, but can be bossy, arrogant and overbearing at times.
With Sun in Virgo: Adds confidence to Virgo’s diffidence and enhances an understanding of the bigger picture. May be bossy and convinced that everyone else is wrong.

Mercury in Virgo

With Sun in Leo: Blends creativity with careful, detailed analysis, which is excellent for business. Practical and down to earth thinking, but with an inner enthusiasm and vigor.
With Sun in Virgo: Highly critical of self and others, but excellent at research and detailed mental work. Permanently on the go, with an inability to truly relax.
With Sun in Libra: Very sociable but prone to gossip. Versatile, adaptable mind, good student. Strong skills in critical analysis but can be hard on self over failure.

Mercury in Libra

With Sun in Virgo: Mitigates Virgo’s tendency to worry and adds an air of serenity and calm. A love of fair play and justice, but some indecisiveness, especially in love.
With Sun in Libra: Can be intellectually lazy. Lots of procrastination. Eminently capable but needs encouragement or strong motivation to take on intellectually challenging work.
With Sun in Scorpio: Adds flexibility against Scorpio’s stubbornness. Expresses emotions easily so does not tend to be secretive. Sympathetic and intuitive.

Mercury in Scorpio

With Sun in Libra: Replaces Libra indecisiveness with determination and a sense of purpose. Intuitive decision making but would benefit from more emphasis on logic and facts.
With Sun in Scorpio: Highly intellectual but may become obsessed with a particular line of thinking. A fascination with all that is hidden; exceptional research skills.
With Sun in Sagittarius: Reigns in some of Sagittarius’ risk-taking and adopts a measured way of thinking, using intuition to back up facts. Relentless in pursuit of answers.

Mercury in Sagittarius

With Sun in Scorpio: Open-minded and optimistic but can have tunnel vision when pursuing a topic of interest. Not above emotional or intellectual manipulation in order to win a battle.
With Sun in Sagittarius: Very agile mind and tons of enthusiasm but a difficulty in focusing or settling down to concentrated work. Mental restlessness can lead to superficiality.
With Sun in Capricorn: Brings a philosophical outlook to Capricorn’s serious demeanor, decreasing the chance of depression or burnout. Well channeled enthusiasm gets results.

Mercury in Capricorn

With Sun in Sagittarius: Practical and versatile, with a strong sense of humor. Able to blend an appreciation for details with a vision of the bigger picture.
With Sun in Capricorn: Hugely ambitious, a very careful and methodical planner. Strong abilities in math and science but can be emotionally cool and quite aloof.
With Sun in Aquarius: Slightly dampens Aquarian individuality and inventiveness but adds practical skill and tenacity. Motivation makes the difference between success and failure.

Mercury in Aquarius

With Sun in Capricorn: A tricky blend of innovation and tradition, with this individual alternately wanting to break the rules or play by the rules. Strong ambitions.
With Sun in Aquarius: Can be a difficult personality, sometimes with extreme views. However, can also be an innovative genius – but struggles to accept ideas from others.
With Sun in Pisces: Blends intuition and objectivity in a very effective mindset. Strongly humanitarian, with lots of empathy and compassion. Potentially strong willed.

Mercury in Pisces

With Sun in Aquarius: May follow an unusual career or have created an offbeat lifestyle. Has no desire to follow the pack. Spiritual nature, with highly developed humanitarian traits.
With Sun in Pisces: Extremely kind and sensitive but can suffer from muddled thinking and overwhelming emotions. Highly creative and likely drawn to the visual arts.
With Sun in Aries: May be forgetful. Acts in haste but for the best of reasons. Uses intuition wisely but can quickly become irritated. May lack a sense of proportion or perspective.