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The Pluto Underground

Pluto session Tues May 9, 1989 AGU in Baltimore

There was a dinner after the Pluto special session at AGU in May 1989 – and the story is that the Pluto Underground started at this dinner. People remember the dinner being at an Italian restaurant. This is not that 1989 occasion.  In 2006, on the occasion of the launch of the New Horizons spacecraft, we had a “re-enactment” of the dinner in Florida.


Ralph McNutt, Alan Stern, Marc Buie, Fran Bagenal (L to R)

The Pluto special session involved these papers: (P22A) – Abstracts: EOS Vol 70 No 15 11 Apr 1989

Pluto session starts on Page 3 – center column. Alan Stern (then at University of Colorado) presiding
Talks are by:
Binzel – Pluto-Charon Mutual Events: Overview and Preliminary Results
Simonelli and Reynolds – The Interiors of Pluto and Charon: Composition, Structure, and Implications
Trafton – Pluto’s Atmosphere Near Perihelion
Dobrovolskis – The Dynamics of Pluto
Millis et al – The Mass Ratio of the Pluto/Charon System
McKinnon – Origin of the Pluto-Charon Binary
Johnson – Effects of Radiation on the Surface of Pluto
Yelle and Lunine – Composition and Thermal Structure of Pluto’s Atmosphere
Lunine and Yelle – Cosmochemical Inferences Concerning the Identity of the Heavier Gas in Pluto’s Atmosphere
Hubbard – Pluto Occultations: Effect of a Large Near-Surface Temperature Gradient
Bagenal and McNutt – The solar wind interaction with Pluto’s a tmosphere
Posters – page 5
Tholen – Results From Five Years of Pluto-Charon Mutual Event Observations
Marcialis – Topographic Relaxation on Ice-Covered Worlds: Application to Pluto II.
Sawyer – Reflectance Spectroscopy of the Surface and Atmosphere of Pluto-Charon
Afterwards there was a dinner. Ralph McNutt recalls it was perhaps Chiapparelli’s in Baltimore’s Italian district.  The details are lost to history.

Special Issue of GRL

With the success of the AGU Pluto session, we followed up with a special issue of Geophysical Research Letters.
GRL vol. 16 issue 11, 1989
Pluto at perihelion
S. A. Stern
First Published:7 December 2012Vol: 16, Pages: 1203DOI: 10.1029/GL016i011p01203Pluto‐Charon mutual events
Richard P. Binzel
First Published:7 December 2012Vol: 16, Pages: 1205–1208DOI: 10.1029/GL016i011p01205The interiors of Pluto and Charon: Structure, composition, and implications
Damon P. Simonelli, Ray T. Reynolds
First Published:7 December 2012Vol: 16, Pages: 1209–1212DOI: 10.1029/GL016i011p01209Pluto’s atmosphere near perihelion
L. M. Trafton
First Published:7 December 2012Vol: 16, Pages: 1213–1216DOI: 10.1029/GL016i011p01213Dynamics of Pluto and Charon
Anthony R. Dobrovolskis
First Published:7 December 2012Vol: 16, Pages: 1217–1220DOI: 10.1029/GL016i011p01217Upper limits on possible photochemical hazes on Pluto
John A. Stansberry, Jonathan I. Lunine, Martin G. Tomasko
First Published:7 December 2012Vol: 16, Pages: 1221–1224DOI: 10.1029/GL016i011p01221Models of Pluto‧s upper atmosphere
Ralph L. McNutt Jr.
First Published:7 December 2012Vol: 16, Pages: 1225–1228DOI: 10.1029/GL016i011p01225Pluto‧s interaction with the solar wind
Fran Bagenal, Ralph L. McNutt Jr.
First Published:7 December 2012Vol: 16, Pages: 1229–1232DOI: 10.1029/GL016i011p01229Effect of irradiation on the surface of Pluto
R. E. Johnson
First Published:7 December 2012Vol: 16, Pages: 1233–1236DOI: 10.1029/GL016i011p01233

Impact jetting of water ice, with application to the accretion of icy planetesimals and Pluto
William B. McKinnon
First Published:7 December 2012Vol: 16, Pages: 1237–1240DOI: 10.1029/GL016i011p01237

Constraints on impact rates in the Pluto‐Charon system and the population of the Kuiper Comet Belt
Paul R. Weissman, Anthony R. Dobrovolskis, S. Alan Stern
First Published:7 December 2012Vol: 16, Pages: 1241–1244DOI: 10.1029/GL016i011p01241


Spring AGU meeting of 1991 in Montreal, Canada

There was another, informal gathering of Pluto fans a couple years later. Alan Stern gave a Pluto talk:
P52B-3 Triton, Pluto, and Charon as Relics of a Large, Ancient
Planetary Ice Dwarf Population. S A Stern (Space Sciences Department, Southwest Research Institute, San Antonio,

Again there was a dinner.Left to right are: Ralph McNutt, Jonathan Lunine, Alan Stern, Mona Delitsky.


Here’s a picture at the same occasion taken by Alan Stern – showing Fran Bagenal