Kepler's problem refers to the challenge of determining the motion of celestial bodies, specifically how planets orbit around a star, such as the Sun. This problem is based on the laws of planetary motion formulated by Johannes Kepler in the early 17th century, which describe the elliptical orbits of planets. The problem involves calculating the positions and velocities of these planets over time, given their initial conditions. It is a fundamental aspect of celestial mechanics and has implications for understanding the dynamics of not just our solar system, but also other planetary systems in the universe.