308 Polyxo

Also known as (308) Polyxo, Polyxo

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: Alphonse Borrelly
Discovery date: 31 March 1891
Pronunciation: / p ə ˈ l ɪ k s oʊ /
Named after: Πολυξώ Polyxō
Minor planet category: Main belt
Adjectives: Polyxoian / p ɒ l ɪ k ˈ s oʊ i ə n /

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Article

308 Polyxo is a main-belt asteroid that was discovered by Alphonse Borrelly on 31 March 1891, in Marseille. It is orbiting the Sun at a distance of 2.75 AU with a low orbital eccentricity (ovalness) of 0.04 and a period of 4.56 yr. The orbital plane is tilted at an angle of 4.36° to the plane of the ecliptic.

308 Polyxo is classified as a rare T-type asteroid, with a spectrum that bears some similarity to the Tagish Lake meteorite. A spectral feature at a wavelength of 3.0 μm suggests aqueous alteration of some surface materials. Photometric measurements reported in 1983 give a rotation period of 12.03 hours and a brightness variation of 0.20 in magnitude. The adaptive optics instrument at the W. M. Keck Observatory shows an oblate object with a diameter of 130 km. The size ratio between the major and minor axes is 1.26 ± 0.11. Light curves for this object suggests it has a very irregular shape.