38 Leda

Also known as (38) Leda, Leda

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.

Key facts

Discovered by: J. Chacornac
Discovery date: January 12, 1856
Designation: (38) Leda
Pronunciation: / ˈ l iː d ə /
Named after: Leda
Alternative names: A904 SF; 1949 QO 2

Article

38 Leda is a large, dark main-belt asteroid that was discovered by French astronomer J. Chacornac on January 12, 1856, and named after Leda, the mother of Helen of Troy in Greek mythology. In the Tholen classification system, it is categorized as a carbonaceous C-type asteroid, while the Bus asteroid taxonomy system lists it as a Cgh asteroid. The spectra of the asteroid displays evidence of aqueous alteration.

Leda has been studied by radar. During 2002, 38 Leda was observed by radar from the Arecibo Observatory. The return signal matched an effective diameter of 116 ± 13 km. This is consistent with some asteroid dimensions computed through other means. Based upon a light curve that was generated from photometric observations of this asteroid at Pulkovo Observatory, it has a rotation period of 12.834 ± 0.001 hours and varies in brightness by 0.15 ± 0.01 in magnitude.