I propose to revert the relocation in 1834 of the name Galilæus from the most prominent lunar swirl, today named Reiner Gamma, to the small crater northwest of it, today named Galilaei.

Originally, in the 1651 map in Riccioli's Almagestum Novum, the lunar swirl was named Galilæus by Giovanni Battista Riccioli in honor of his contemporary, Galileo Galilei. The naming remained until 1834, when Johann Heinrich von Mädler's map showed it as just the letter γ, the third minor feature of nearby crater Reiner. The name Galilæus was moved, with that map publication, to an unnamed small crater 150 km northwest of the lunar swirl, now called Galilaei.

That name change of 1834, without documentation of the reasoning for the change, of the lunar swirl away from Galilæus to Reiner Gamma, was then adopted by the IAU in 1935.

This change of 1834 I propose to revert, and to avoid confusion which would be created when changing the crater name Galilaei, a new name should be given to the lunar swirl, currently known as Reiner Gamma: Galilaei Impulsus

Explanation of the new compound name:

• Galilaei: to return the name honoring Galileo Galilei to the original 1651 location
• Impulsus: for the scientific impulse Galileo sparked during his era, and to be potentially used as a new name class for lunar swirls.

If you agree with the name change from Reiner Gamma to Galilaei Impulsus, please sign here.

Your signing will help to convince the USGS to accept the renaming, as publisher of the Gazetteer of Planetary Nomenclature, which is the authoritative directory, sanctioned by the International Astronomical Union (IAU), of all officially approved names for topographic features, albedo features, and rings on planets, dwarf planets, and natural satellites in our solar system.

Further details about the original name history, maps and photos: areo.info/galileo