VLT´s UT2 coating

The primary mirror (M1) of UT2, already detached from the telescope structure, is being covered for its transportation from the telescope to the Main Maintenance Building (MMB), where it will be recoated. The purpose of this cover is to avoid that the sun hits the mirror. The cleaning of the VLT´s M1s is a very delicate operation which takes place every 18 months and consists in removing the reflective aluminum layer by chemical washing and then recoating the mirror.