Esophageal cancer describes the disease where cells that line the esophagus change or mutate and become malignant. These cells grow out of control and form a mass or tumor. There are two main types of esophageal cancer:
Trajectory. A trajectory is the path that a moving object follows through space as a function of time. The object might be a projectile or a satellite, for example. It thus includes the meaning of orbitâthe path of a planet, an asteroid or a comet as it travels around a central mass.
The curve described by a body moving through space, as of a meteor through the atmosphere, a planet around the Sun, a projectile fired from a gun, or a rocket in flight. In general, the trajectory of a body in a gravitational field is a conic sectionâellipse, hyperbola, or parabolaâdepending on the energy of motion.