2 Pallas (pal'-us) was the first asteroid discovered after 1 Ceres. It was found and named by H. Wilhelm Olbers on March 28, 1802. It was named after the feminine Pallas of Greek mythology, the daughter of Triton and friend of Athena. There are several other Pallantes (the masculine plural of Pallas) in Greek mythology: amongst them a Titan, and a goatish Giant. However, the first asteroids were invariably given female names.

Pallas is the second largest Main belt asteroid, only a little larger than 4 Vesta. Its orbit is located in the central part of the belt but it is somewhat inclined and eccentric for a large asteroid. The composition of Pallas is unique but quite similar to the C-type asteroids.

Pallas has been observed occulting a star several times. Careful occultation timing measurements have helped give it an accurate diameter.

During the occultation of May 29, 1979 the discovery of a possible tiny satellite with a diameter of ~1 km was reported. However, it has not been confirmed. In 1980, speckle interferometry was reported as indicating a much larger satellite with a diameter of 175 km, but the existence of the satellite was later refuted. (1)

Pallas has not yet been visited by a spacecraft, but if the Dawn probe is successful in studying 1 Ceres and 4 Vesta, its mission may be extended to Pallas.

The chemical element palladium (atomic number 46) was named after Pallas.

References

• James L. Hilton, U.S. Naval Observatory Ephemerides of the Largest Asteroids (1999)
• E. V. Pitjeva, Estimations of Masses of the Largest Asteroids and the Main Asteroid Belt From Ranging to Planets, Mars Orbiters And Landers (2004)
• IRAS Minor Planet Survey