204 Kallisto is a fairly typical, altough sizeable Main belt asteroid. It is classified as a S-type asteroid and is probably composed of a mixture of silicates and metals. Like other asteroids of its type, it is light in colour.

It was discovered by Johann Palisa on October 8, 1879 in Pola.

The asteroid was named after the same nymph Callisto in Greek mythology as Jupiter's moon Callisto.

References

• The Asteroid Orbital Elements Database
• Minor Planet Discovery Circumstances
• Asteroid Lightcurve Parameters
• Asteroid Albedo Compilation