Jason is a planetary scientist at the
Southwest Research Institute (SwRI) in Boulder, Colorado. His research is focused on understanding the
physics of presently-active geologic processes in the
solar system. As a graduate student at
Cornell University, he led the Cassini RADAR team in the first discovery and
later confirmation of transient features in the hydrocarbon seas of Saturn’s
moon Titan. These enigmatic features, popularly known as “Titan’s Magic
Islands” were determined to be waves, floating or suspended solids, or
bubbles. As a NASA Postdoctoral Program Fellow at the Jet Propulsion
Laboratory (JPL), he modeled volatile transport on Kuiper belt object (KBO)
Eris and led the New Horizons team in a search for temporal changes on Pluto
and its moon Charon. Eris was predicted
to be in an unfamiliar atmospheric regime and despite its small size and solar
distance of almost 100 times that of the Earth, to have extensive ongoing
resurfacing. Temporal changes were not
detected in New Horizons observations but Pluto was
found to have terrains with extraordinarily different albedos, larger in
absolute difference than any other solar system body, and several enigmatic
features. Recently, he demonstrated that
the extraordinary radar albedos and circular polarization ratios of icy moons
of Jupiter and Saturn are correlated and that all six previously published
models to explain the extraordinary icy-moon radar properties fail to
satisfactorily fit this new constraint.
However, a modestly adapted model that includes the coherent backscatter
opposition effect (CBOE) successfully fits the correlation as well as all other
radar constraints. Jason’s other
research results include remote sensing tests to distinguish between competing
hypotheses for plumes on Neptune’s moon Triton, spatially-resolved
measurement of the albedo of KBO Arrokoth, and
resolution of a more than decade-old apparent discrepancy between Arecibo
Observatory and Cassini radar observations of Titan. Jason has experience on two NASA missions,
Cassini and New Horizons, and made significant contributions to three mission
proposal/concept teams, Europa Lander, Trident (Triton), and Oceanus
(Titan). Jason’s current research
includes investigating the enigmatic features discovered on Pluto, modeling
seasonal volatile transport on Eris and other KBOs, analyzing Cassini radar
observations of Titan, and developing future planetary missions.
Jason’s CV is available here.
He can be reached at jason
dot hofgartner at swri dot
org.
A SwRI release about results regarding the
extraordinary radar properties of icy satellites of Jupiter and Saturn and the
adapted CBOE model is available here.
An interview about Triton’s plumes is
available here.
A blog about the resolution of the apparent
discrepancy between Arecibo Observatory and Cassini radar observations of Titan
and hypothesis that paleolakes and paleoseas (areas
that were formerly lakes and seas) are the source of the anomalous observations
is available here.
An example media article about this research is ScienceNews.
NASA releases about Titan’s Magic Islands can
be found here
and here.
Example media articles about Titan’s Magic Islands include: BBC and CSMonitor.
Incidence-angle-average bolometric
hemispherical albedo (local energy-balance albedo, equal to one minus
absorption) map of Pluto is available here
on NASA’s Planetary Data System archive.
Normal reflectance and
incidence-angle-average hemispherical albedo maps of KBO (486958) Arrokoth are available here
on NASA’s Planetary Data System archive.
This website was last updated on June 18th,
2024.