Astrology of Midlife and Aging, by Erin Sullivan, from Jeremy P. Tarcher Inc., ISBN 1585424080. Between the ages of 37 and 41, something mysterious takes place within the psyche. There exist no maps of this unexplored terrain—except the natal horoscope. In this in-depth analysis, acclaimed astrologer Erin Sullivan takes us through the vast changes our birth charts reveal as we reach middle age. It is a moment in life characterized by the planet Uranus, an opportunity to both rethink the past and move forward toward the future, "witnessing" our lives in the way Uranus connotes.