Dr. Paul Sutter, visiting professor at Barnard College and external advisor for NASA's Advance Concepts Program, joins the "ROI" team for a discussion about:  The Top Five Astronomical Discoveries Of All Time (So Far).

The host for the 617th episode in this series is John Kealey, and the history buffs are Terri Toppler and Ed Broders.

Opinions expressed in this program are those of the hosts and the guest(s), and not necessarily those of KALA-FM or St. Ambrose University. This program is recorded at KALA-FM, St. Ambrose University, Davenport, Iowa, USA!