Discovered in the archive

How a moon imaged in 2003 was only recognised in 2004.

Published 2026-10-23

Not every discovery happens the night a picture is taken. Thelxinoe was found in 2004 from pictures taken in 2003.^[1]

The images

NASA dates the discovery images to 9 February 2003 at Mauna Kea, crediting Scott Sheppard and Brett Gladman.^[2]

Why it takes time

A tiny, faint moon has to be picked out among many moving points of light and followed over time to prove it orbits Jupiter.

The designation

It received the provisional designation S/2003 J 22 — the year of the images, not of the recognition.^[1]

Numbered citations link to the sources list on the Thelxinoe overview page.