When did Heinrich Wilhelm Matthias Olbers discover 2 Pallas?
Heinrich Wilhelm Matthias Olbers discovered 2 Pallas on the night of the 28th of March 1802. This event occurred just months after Giuseppe Piazzi found Ceres in 1801.
Questions about 2 Pallas
Short answers, pulled from the story.
What is the current diameter of 2 Pallas compared to early estimates?
Scientists revised the size of 2 Pallas down to 673 kilometers by 1979, which remains 26% greater than today's accepted value. Early estimates reached as high as 3,380 kilometers in diameter shortly after discovery.
How does the orbit of 2 Pallas differ from other large solar system bodies?
Pallas orbits with an inclination of 34.8 degrees relative to the ecliptic plane, making it unusually accessible compared to most other large solar system bodies. Its orbital eccentricity approaches values seen in Pluto itself and it maintains a near-1:1 resonance with Ceres while holding a 5:2 resonance with Jupiter over 83-year cycles.
What minerals make up the surface composition of 2 Pallas?
Spectroscopic data reveals that 2 Pallas has a B-type asteroid composition rich in olivine and pyroxene minerals. The surface resembles Renazzo carbonaceous chondrite meteorites discovered in Italy during 1824 and contains little iron and water compared to similar objects like Ceres.
Has any spacecraft ever visited 2 Pallas directly?
No spacecraft has ever visited 2 Pallas directly despite multiple proposals over decades. High orbital inclination prevented flyby opportunities for the Dawn probe visiting nearby asteroids and funding competition ultimately favored other concepts like TransOrbital Trailblazer Lunar Orbiter instead.