1. The point in an orbit around a star or other celestial body at which an orbiting object is closest to that body.
Usage: astronomy; technical

Examples

• The comet reaches its periapsis every 76 years when it comes closest to the Sun.
• Astronomers calculated the periapsis of the exoplanet's orbit around its host star.
• At periapsis, the spacecraft experiences its strongest gravitational pull from the planet.
• The satellite's periapsis altitude determines how close it approaches Earth's surface.
• Scientists study periapsis data to understand the orbital mechanics of binary star systems.