How you take action
You act when something matters to you emotionally. Defending your family, looking after a friend, making a home safe: these can bring out more determination than any abstract goal. Cardinal water gives you initiative, but you often move sideways first, testing the ground before you commit. You tend to trust your gut about when to act and when to wait.
Ambition and work
Your ambition is usually tied to security, for yourself and for the people you care about. Astrologers link this placement with work that involves caring, feeding, housing, teaching or building a team that feels like family. You may work hardest when you know who you are doing it for. Recognition matters less to you than knowing the people around you are safe.
Anger and conflict
Your anger tends to be indirect. You may feel hurt before you feel angry, and you might withdraw, go quiet or show displeasure through moods rather than words. When you do express it, it can come out with surprising force because it has been held in. Naming what you feel early, and asking directly for what you need, keeps old hurts from building up.
Desire and attraction
For you, desire is bound up with emotional safety. Astrologers often say Mars in Cancer needs to feel trust before it can fully open up, and that closeness and tenderness are part of attraction rather than an extra. You are drawn to people who are kind, loyal and protective, and you show interest by taking care of someone.
Physical energy
Your energy rises and falls with your mood, much like the Moon that rules Cancer. Traditionally this placement is linked with doing best in a familiar, comfortable setting, such as swimming, home workouts or exercise with people you trust. Noticing how your feelings affect your drive helps you plan around the low tides instead of fighting them.
Challenges
Holding things in is the main hurdle. You may avoid direct conflict and then let resentment come out sideways, or act defensively when you feel criticized. Protectiveness can tip into worry or control. Learning to say no plainly, and to ask for what you want without waiting to be guessed, lets your strength show without the detours.
How long Mars stays in Cancer
Mars takes about 687 days to orbit the Sun, so seen from Earth it comes back to Cancer roughly every 1.9 years. Between 1960 and 2040 it passes through Cancer 43 times. A typical passage lasts 47 days, and the shortest 45 days. The longest, from Sep 12, 1992 to Apr 27, 1993, adds up to 228 days in Cancer, because Mars turned retrograde in or near the sign. In this period, 6 passages last more than 100 days. Everyone born during the same passage shares a Mars in Cancer, so the house and aspects of Mars in your own chart add the personal detail.