The burning-hot, red planet, named after the ancient God of War, represents the pure masculine energy and all related concepts.
On the positive side, it reflects qualities such as bravery, courage, protectiveness, resolve to take action, vigorous pursuit of desires and beliefs. Its mission in life is to unapologetically externalize the true self. On the more anti-social side, it symbolizes violence, aggression, anger, going to extremes, confrontation, forcefulness, danger, military action.
Anything that cuts, dissects and penetrates; anything that acts quickly and decisively without considerations of consequences or poise; everything that feels raw and animalistic, is of the nature of Mars.
Mars is the protector and the aggressor, the direct uncontained answer to any situation.
The essence of Mars's approach to life is "I see it, I begin to desire it, I go for it." A spark becomes a fire very quickly. And vise versa. The time between impulse and action is short. Contemplation and strategizing are not on the menu. Primal energy and power are the order of the day. Every day.
At the core of Mars's nature is the unignorable, unsilencable impulse to act now and act to the fullest. There is a sense of uncontainable fire that has to be expelled out of your system now and fully. The moment for everything is always now and always right. Why wait? Why contemplate? The moment is now. Passion, ambition, drive that mark your entire being - from the way you talk to the way you structure your life.
Wherever Mars falls in a person's chart, that where this person is likely to act on impulse, immediately after the spark inside them has been lit. Without thinking, without planning, without consideration for sequences, the urge to express the fire inside is too strong to resist.
In astrology, Mars is considered the lesser malefic - wherever it is in someone's chart, that's where this person is prone to experience accidents. This is where short-lived but extreme events are most likely to occur.
Mars rules over the first sign of the zodiac Aries. It is competitive, challenges-loving, trouble-searching, a sign that needs to come on top.
People with a prominent Mars in their chart tend to be very fond of sports. Competing against themselves and challenging their own body strength are typical hobbies.
These people are direct and open about what they want which often gives them the reputation of having "no filter", respecting no boundaries, a reputation of being aggressive and (c)rude. But in reality, direct and open are more appropriate words to describe them. They see no value in "beating around the bush" i.e. in trying to adapt the real nature of their desires to the audience, the very thing that their opposite energy of Venus would call diplomacy and tact.