23 Thalia

Also known as (23) Thalia, Thalia

main-belt asteroid

AI overview

23 Thalia is an asteroid located in the main belt between Mars and Jupiter. It is one of the named asteroids in this region and contributes to our understanding of the solar system's composition and structure.

AI-generated from the Wikipedia summary — may contain errors.

Picture of the Day · NASA

Pathfinder on Mars

2026-07-04

On July 4th, 1997, using its own array of fireworks, a parachute, and a cocoon of airbags, the Mars Pathfinder spacecraft bounced like a giant beach ball at least 15 times before it came to rest on the surface of Mars at 10:07 AM Pacific Daylight Time. After its then novel airbag-assisted landing sequence was completed, Pathfinder transmitted this color mosaic to mission operators on Earth. In the scene from another world, the Mars Sojourner robot rover is visible in the foreground, crouched on top of the unfolded Pathfinder. About the size of a large house cat, the six-wheeled, solar-powered Sojourner became the first successful Martian rover. Surrounding Pathfinder are deflated airbags and the rock-strewn terrain of the Ares Vallis floodplain. In the distance Martian hills appear against a dusty brownish sky. The Pathfinder lander was subsequently renamed the Carl Sagan Memorial Station.

via NASA APOD

Key facts

Discovered by: J. R. Hind
Discovery date: 15 December 1852
Pronunciation: / θ ə ˈ l aɪ . ə /
Named after: Thalia
Alternative designations: 1938 CL; 1974 QT 2
Minor planet category: Main belt
Aphelion: 484.663 million km (3.240 AU)
Perihelion: 301.483 million km (2.015 AU)
Semi major axis: 393.073 million km (2.628 AU )
Orbital period sidereal: 1555.679 d (4.26 a )
Mean anomaly: 328.687°
Inclination: 10.145°
Longitude of ascending node: 67.228°
Argument of perihelion: 59.311°
Dimensions: 107.53 ± 2.2 km ( IRAS ) , 106.81 ± 3.23 km
Mass: (1.96 ± 0.09) × 10 kg
Mean density: 3.07 ± 0.31 g/cm
Synodic rotation period: 12.312 h

via Wikipedia infobox

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Encyclopedic overview

23 Thalia (/θəˈlaɪ.ə/) is a large main-belt asteroid. It was discovered by J. R. Hind on 15 December 1852, at the private observatory of W. Bishop, located in Hyde Park, London, England. Bishop named it after Thalia, the Muse of comedy and pastoral poetry in Greek mythology.

It is categorized as an S-type asteroid consisting of mainly of iron- and magnesium-silicates. This the second most common type of asteroid in the main belt. Based on analysis of the light curve, the object has a sidereal rotation period of 0.513202 ± 0.000002 days. An ellipsoidal model of the light curve gives an a/b ratio of 1.28 ± 0.05.

Excerpted from Wikipedia’s “23 Thalia” article, available under the CC BY-SA 4.0 licence.