The planet that is located one astronomical unit (AU) from the Sun is Earth.
An astronomical unit is a standard unit of measurement used in astronomy to represent the average distance between the Earth and the Sun, approximately 93 million miles or about 150 million kilometers. This measurement helps astronomers describe distances within our solar system more easily. Since Earth orbits the Sun at this average distance, it is often used as a reference point for measuring distances to other celestial bodies.
To give a bit more context, other planets in our solar system are located at different distances from the Sun. For instance, Mercury is much closer, while Mars is a little over 1.5 AU away. This concept of the astronomical unit is crucial for understanding the vastness of space and the relative distances that exist between planets.