The Fate of Pluto’s Atmosphere

Editor’s note: this is circulating widely among the planetary science community.

Date: Tue, 30 Jul 2002 15:58:39 -0700

From: John Stansberry stansber@as.arizona.edu

The paper Roger Yelle and I published in Icarus in 1999,
“The Fate of Pluto’s Atmosphere,” is now suffering a perhaps
appropriate fate for a paper with such a pretentious title.
The paper suggests that an interesting and unique climatological
effect may play a role on Pluto, but also states repeatedly
that the conclusions are highly preliminary and based on a
number of assumptions.

As we said in the conclusions to the paper:

1) The model is simplistic.

2) The absence of atmospheric collapse assumes a somewhat
static frost distribution (i.e. thick frost).

3) The model is valid only if the atmosphere remains isobaric
at the “non-collapsed” pressure of ~3ubar (a factor of
something like 10 less than the 1989 pressure in my opinion).

4) Other factors (albedo, grain evolution, vertical stratification
and/or annealing in the surface) could also exert important
and unaccounted for influences.

5) More detailed modeling is possible and probably desirable in
view of a possible spacecraft mission to Pluto.

In my opinion the current Pluto funding controversy doesn’t revolve
around science. The DPS and NRC have both given the mission the
very highest endorsements they can, including DPS mailing 02-22.
The controversy only exists because some folks at OMB have gotten
their noses bent out of shape and are determined to take it out
on the planetary science community. I strongly doubt that anything
I do or write is going to influence the outcome of that controversy,
and might have the undesireable effect of obscuring the OMB’s motives
in a (thin) veil of science.

I do not believe that our paper in any way suggests that delaying
the Pluto mission is an appropriate course, and I think the paper
itself makes that point fairly clearly. If it appears to any of
you that the 99 paper is being used to advocate a delay in the
mission, please feel free to refer the offending party to this
letter. I have decided not to write any letters to editors or the
like on this topic at this time.

Best Regards,

John