[Add observation]

Observation 1
Feature(s)	GRS Oval BA Ganymede
Filter(s)	ir
Date	2018-06-22 09:41:30
Julian day	2458291.9034722224
System I	25.71°
System II	3.23°
System III	239.54°
Illumination	99.5%
Phase angle	7.9°
Solar longitude	311.2°
Eq. diameter	42.32″
Derotation	7.0 min