When a cold air mass replaces a warm air mass, it's called a(n) front?

When a cold air mass replaces a warm air mass, this is called a cold front. Some characteristics of a called front before passing are winds coming from south or southwest area, warm temperature, falling pressure, and drizzles. When it passes, the winds are shifting, there is a sudden drop of temperature, minimum pressure followed by a sharp rise. After passing, the winds head to the west or northwest area, temperature is steadily dropping and the pressure is rising steadily.

The answer is orbit around nucleus