423 Diotima

Also known as (423) Diotima, Diotima

main-belt asteroid

Picture of the Day · NASA

Jupiter and Venus from Earth

2026-06-07

It was visible around the world. The sunset conjunction of Jupiter (left) and Venus (right) in 2012 was visible almost no matter where you lived on Earth. Anyone on our planet with a clear western horizon at sunset could see them. That year, a creative photographer traveled away from the town lights of Szubin, Poland to photograph a near closest approach of the two planets. The bright planets were then separated by only three degrees and his daughter struck a humorous pose. A faint red sunset still glowed in the background. Jupiter and Venus are together again this week after sunset, passing within a degree of each other about two days from today.

Small body data

423 Diotima (A896 XA)

Orbit class: Main-belt Asteroid
Diameter: 175.859 km
Albedo: 0.067
Rotation period: 4.775 h
Absolute magnitude: 7.380 H
Earth MOID: 1.950 AU

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Article

423 Diotima is one of the larger main-belt asteroids. It is classified as a C-type asteroid and is probably composed of primitive carbonaceous material.

It was discovered by Auguste Charlois on 7 December 1896, in Nice. In the late 1990s, a network of astronomers worldwide gathered lightcurve data that was ultimately used to derive the spin states and shape models of 10 new asteroids, including 423 Diotima. The light curve for this asteroid varies "a lot" depending on the position, with the brightness variations ranging from almost zero to up to 0.2 in magnitude. Dunham (2002) used 15 chords and obtained an estimated size of 171 km × 138 km.