Hesperian

views updated May 18 2018

Hesperian western. XVI. f. L. hesperius, Gr. hespérios, f. Hesperia, Gr. Hespería (poet.) land of the west, f. Hesperus, Hésperos, adj. western, sb. evening star; see -IAN.

Hesperian

views updated May 08 2018

Hesperian A division of areological time, lasting from 3.50 Gy to 1.80 Gy in the Hartmann—Tanaka Model and 3.80 Gy to 3.55 Gy in the Neukum—Wise Model, and divided into two epochs: Lower Hesperian (3.50–3.10 or 3.80–3.70 Gy); and Upper Hesperian (3.10–1.80 or 3.70–3.55 Gy).