Psyche

Psyche (16 Psyche) is the sixteenth asteroid discovered, discovered in 1852, which is about the time that astronomers began to consider asteroids no longer to be official planets. It lies in the main asteroid belt, roughly between the orbits of Mars and Jupiter. Both its albedo characteristics and mass determinations through perturbation observations suggest it includes iron and nickel, its bulk density somewhat greater than that of rock. Characteristics:

• 3.8 × 10^-6 Earth masses (0.0003 Moon masses).
• 223 km mean diameter.
• 3.98 g/cm³ - bulk density.
• 5 years - orbital period.
• 4.2 hours - solar day.
• 2.92 AU - orbital radius (semi-major axis).
• 0.134 - orbital eccentricity.

Psyche has no moons. A NASA mission to 16 Psyche, called simply Psyche, was launched in October 2023, planning to reach Psyche in 2029.