Thomas Pesquet posted a photo:

Expedition 50 Earth observation composite of the Richat Structure, also known as the Eye of Sahara and Guelb er Richat, in the Sahara near Ouadane in west-central Mauritania, western Africa.

Zoomable version here: www.esa.int/ESA_Multimedia/Images/2021/05/Richat_reassembled

Composite created wtih iss050e070090-iss050e070110.

jsc2017e064007