17 Thetis

Also known as (17) Thetis, Thetis

main-belt asteroid

AI overview

17 Thetis is an asteroid located in the main belt between Mars and Jupiter. While it's one of many thousands of asteroids in this region, studying objects like 17 Thetis helps scientists understand the composition and history of our early solar system.

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

Wikidata facts

Instance of: asteroid
Named after: Thetis
Followed by: 18 Melpomene
Follows: 16 Psyche
Parent body: Sun
Minor-planet group: asteroid belt
Diameter: 84.899
Mass: 1.2
Orbital period: 1420.32543862613
Image: 17Thetis-LB1.jpg

Show 20 more facts

discoverer or inventor: Robert Luther
Commons category: 17 Thetis
site of astronomical discovery: Düsseldorf-Bilk Observatory
provisional designation: A852 HA
time of discovery or invention: 1852-04-17
asteroid spectral type: S-type asteroid
orbital inclination: 5.59392352875983
density: 3.21
rotation period: 12.27048
albedo: 0.193
absolute magnitude: 7.92
orbital eccentricity: 0.1312583946368459
semi-major axis of an orbit: 2.472822587765194
periapsis: 2.148243864673404
apoapsis: 2.797401310856984
longitude of ascending node: 125.5027942281128
argument of periapsis: 135.9494648139404
mean anomaly: 192.6616443294702
time of periapsis: 2461660.708120602
epoch: November 21, 2025

Sources (2)

via Wikidata · CC0

~2 min read

Encyclopedic overview

Lightcurve-base 3D-model of 17 Thetis. 17 Thetis is a stony asteroid from the inner regions of the asteroid belt, approximately 90 kilometers in diameter. It was discovered on 17 April 1852, by German astronomer Robert Luther at Bilk Observatory in Düsseldorf, Germany who deferred to Friedrich Wilhelm August Argelander the naming his first asteroid discovery after Thetis from Greek mythology. Its historical symbol was a dolphin and a star; it was encoded in Unicode 17.0 as U+1CECA 𜻊 ().

Description

Excerpted from Wikipedia’s “17 Thetis” article, available under the CC BY-SA 4.0 licence.