Moons with three dips

What Hyrrokkin’s odd light curve suggests.

Published 2026-10-23

A light curve plots an object’s brightness over time.^[5]

Two dips is normal

An elongated body usually brightens and dims twice per rotation.

Three dips

Hyrrokkin’s light curve shows three minima, like Ymir and Siarnaq — but one is much shallower than the others.^[1]

Measured by Cassini

Four observations in March 2013 gave about 12 h 45 min, refined to 12.76 ± 0.03 hours.^[1]

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