What number asteroid is named Pandora in the Solar System?

The asteroid named Pandora is 55 Pandora.

55 Pandora is a relatively large main-belt asteroid orbiting the Sun between the orbits of Mars and Jupiter. The number 55 records its place in the historical sequence of numbered asteroid discoveries, while Pandora is its mythological name.

The asteroid was discovered by the American astronomer George Mary Searle at the Dudley Observatory in Albany, New York, in 1858. It was later named for Pandora, the figure from Greek mythology whose opening of a container released troubles into the human world.

55 Pandora should not be confused with Pandora, a moon of Saturn, or Pandora in James Cameron’s Avatar. Those objects share a mythological name but occupy entirely different settings. Astronomical numbering is especially useful here because it gives the asteroid an unambiguous identity.