The UMD Department of Astronomy cordially invites you to the

Mike A'Hearn Endowed Lecture

with

Jonathan Lunine

Caltech/JPL

on

The Search for Habitability and Life in the Ocean Worlds of our Solar System

Wednesday, October 21, 2026

3:30-4 p.m.

Pre-lecture Reception, Atlantic Building (ATL) 2400 Atrium

4:05-5 p.m.

Lecture, Atlantic Building (ATL) 2400

5:15-6 p.m.

Post-Lecture Reception in Physical Sciences Complex (PSC) 1136

Paid parking is available on the roof of Regents Drive Garage. Please visit a pay station before you leave the garage roof. Additionally, the free #104 ShuttleUM bus runs between the College Park Metro Station and Regents Drive at about 15-minute intervals.

If you have a question about this event, including disability accommodations, please contact Barbara Hansborough at barbarah@umd.edu or 301-405-1508.

About the Talk

The exploration of the outer solar system in the past half-century has revealed multiple worlds with oceans of liquid water and, in one case, seas of liquid methane and ethane (Titan). Enceladus has an ocean whose ingredients seem to satisfy the basic requirements for supporting life. Europa has a vast ocean whose habitability will be explored at the end of this decade by Europa Clipper. And the proposition that a form of biology could have evolved in the methane seas of Titan stretches the limits of what we might call life. I will take us on a tour of what we know and need to know in the search for life beyond Earth.

About the Lecture

Ralph Pass (B.S. '68, M.A. '72, Ph.D. '78, mathematics) established the Mike A'Hearn Endowed Lectureship in 2020 in memory of UMD Distinguished University Professor of Astronomy Michael "Mike" Francis A'Hearn (1940-2017). Pass worked on all the manned Apollo missions and other NASA projects and credited A'Hearn as one of the top influencers of his academic life.

A renowned cometary astronomer, A'Hearn is perhaps most recognized as principal investigator and project leader of the spacecraft mission, Deep Impact, which resulted in the close exploration of two comets. However, his interests and reputation were broad and far beyond the cometary field. While UMD was his home, his reach encompassed the entire planetary astronomy community and the scientific community overall—both nationally and internationally. He was a brilliant scientist, a respected and influential collaborator, an inclusive team leader, and a most encouraging mentor to countless undergraduate and graduate students as well as young scientists. His legacy in the scientific community is remarkable.