It was not until 1997 that its unusual orbit was found by Paul Wiegert and Kimmo Innanen , working at York University in Toronto , and Seppo Mikkola , working at the University of Turku in Finland . It was not until 1997 that its unusual orbit was determined by Paul Wiegert and Kimmo Innanen , working at York University in Toronto , and Seppo Mikkola , working at the University of Turku in Finland .