Professor Kim Innanen had asteroid named after him

An original member of York’s Department of Physics & Astronomy, who helped prove asteroids travel through space with Earth and had one named after him, has died at age 74. Professor Emeritus Kim Innanen died at Sunnybrook Medical Centre on Aug. 3.

Prof. Innanen arrived at York in 1966, taught until 2002 and served as dean of the Faculty of Pure & Applied Science from 1986 to 1994. Prior to his arrival at York, he was an assistant professor of mathematics and astronomy at the University of Western Ontario from 1963 to 1966.

Kim Innanen with son Kristopher, a professor at the University of CalgaryLeft: Kim Innanen with son Kristopher, a professor at the University of Calgary. Photo by Prof. Irving Rothman, University of Houston

Prof. Innanen is survived by his wife, Sandra, and his three children, all York grads: daughter Sally (BSC Hons. ’91, MES ’96) and son Kristopher (BSC Hons. ’96, MSC ’98), who met his wife Kathleen Keates (BA ’95) at York, and Andrew (BA ’98), who gave the eulogy at a memorial service Wednesday. He is also survived by his brother, York grad Veikko Innanen (PhD ’74), a former director of Sunnybrook Health Science Centre.

In a recollection of his career written for an article about York’s 40thanniversary, Prof. Innanen credited Ralph Nicholls, distinguished research professor emeritus (physics)  and a founding member of the Faculty of Science & Engineering, with bringing him to York. Nicholls hired Sandra as a research assistant when he arrived at York in 1965, and Prof. Innanen used to joke that, to get her, Nicholls had to hire him too.

Prof. Innanen, who was also a professional engineer, wrote that he was intimately involved with the construction of the two observatories attached to the Petrie Science & Engineering Building, and helped confirm the decision to build them as separate structures to limit vibration that could affect the two telescopes. Innanen recalled that he also initiated the tradition of public access to the observatories, which continues to this day.

In his obituary, the family noted that Prof. Innanen’s research in classical mechanics, relating to galactic astronomy and later to planetary astronomy, brought him together with Finnish astronomers at the universities of Helsinki and Turku. His contributions to the field were recognized there by the awarding of an honorary degree from the University of Turku, and the naming of Asteroid 1941HJ, “Asteroid Innanen”.

His continued research with his colleagues, up until this year, has contributed greatly to the knowledge of Trojan asteroids and near earth bodies.The term “Trojans” refers to an asteroid or moon that shares the same orbit as a larger planet or moon. In 1986, Prof. Innanen, Finnish colleague Prof. Seppo Mikkola of Tuorla Observatory, University of Turku, and Paul Weigert discovered an asteroid accompanying Earth in its orbit around the sun. Their findings, published in Nature in 1997, helped to further explain our solar system’s origins.

Marshall McCall, chair of York’s Department of Physics & Astronomy, Faculty of Science & Engineering attended the memorial service and said Weigert, who was a post-doctoral research fellow at the time, was able to inform Prof. Innanen about the discovery of earth’s first Trojan asteroid, announced July 27, just before he died.

The three colleagues also predicted the existence of Mars Trojans, the first of which was later discovered.

In later years, Prof. Innanen, Wiegert, now a professor at the University of Western Ontario, and Prof. Mikkola showed that four asteroids share the Earth’s orbit in a most strange resonance. The asteroids 3753 Cruithne, 1998 UP1, 2000 PH5, and 2002 AA29 share the Earth’s orbit while orbiting, not in an ellipse, but in a horseshoe pattern.

Kimmo Albin Innanen, BASc, MSc (University of Waterloo), PhD (University of Toronto), was born to Finnish parents, Albin and Fanny Innanen, at Kirkland Lake, Ont., on March 12, 1937. At an early age, his family moved to Toronto to ensure that he and his brother Veikko had access to a good education, of which they both took full advantage. The family was involved with the strong Finnish community in the city and connections with Finland were kept up, with Kim’s fluency in the Finnish language helping a great deal.

The memorial service was held on Wednesday at Agricola Finnish Lutheran Church in Toronto, and York’s flag was flown at half-mast on Tuesday.