In Memoriam Jack Welch

March 15, 2024

JackWelch informal

It is with sadness that we note the death of Professor W.J. (Jack) Welch on March 10, 2024.  Jack held appointments in both the Astronomy and Electrical Engineering departments and was a leader in the field of radio astronomy.

In the late 1960’s Jack and Charles Townes made the first detections of ammonia  and water in interstellar space, using a radio telescope at the University of California’s Hat Creek Radio Observatory.  This seminal discovery triggered the detections of dozens of additional interstellar molecules by astronomers, enabled detailed studies of star formation in interstellar clouds, and launched the field of astrochemistry.

Jack pioneered the field of millimeter wavelength interferometry, first with the Hat Creek Interferometer, then with the Berkeley-Illinois-Maryland array.  The success of these instruments led to the construction of even more capable telescope arrays — CARMA, and ultimately ALMA. 

With his wife Jill Tarter, Jack was a founding member of the SETI Institute.  He played a central role in the design and development of the Allen Telescope Array, the first observatory built specifically to conduct SETI research.

Jack’s enthusiasm, kindness, and guidance inspired many students who went on to make their own contributions to radio astronomy.

Read Jack Welch’s extensive obituary at the SETI Institute