/serr"tis/
an area in the northern hemisphere and near the equator of Mars, appearing as a dark region when viewed telescopically from the earth.
/serr"tis/
an area in the northern hemisphere and near the equator of Mars, appearing as a dark region when viewed telescopically from the earth.
Random House Webster's Unabridged English dictionary. Полный английский словарь Вебстер - Random House . 2012