Detectability of thermal signatures associated with active formation of ‘chaos terrain’ on Europa

Earth and Planetary Science Letters
By: , and 



A recent study by Schmidt et al. (2011) suggests that Thera Macula, one of the “chaos regions” on Europa, may be actively forming over a large liquid water lens. Such a process could conceivably produce a thermal anomaly detectable by a future Europa orbiter or flyby mission, allowing for a direct verification of this finding. Here, we present a set of models that quantitatively assess the surface and subsurface temperatures associated with an actively resurfacing chaos region using constraints from Thera Macula. The results of this numerical study suggest that the surface temperature over an active chaos region can be as high as ∼200 K. However, low-resolution Galileo Photo-Polarimeter Radiometer (PPR) observations indicate temperatures below 120 K over Thera Macula. This suggests that Thera Macula is not currently active unless an insulating layer of at least a few centimeters in thickness is present, or activity is confined to small regions, reducing the overall intensity of the thermal signature. Alternatively, Thera may have been cooling for at least 10–100 yr and still contain a subsurface lake, which can take ∼300,000 yr to crystallize. According to the present study, a more sensitive instrument capable of detecting anomalies ∼5 K above ambient could detect activity at Thera Macula even if an insulating layer of ∼50 cm is present.


Publication type Article
Publication Subtype Journal Article
Title Detectability of thermal signatures associated with active formation of ‘chaos terrain’ on Europa
Series title Earth and Planetary Science Letters
DOI 10.1016/j.epsl.2013.09.027
Volume 384
Year Published 2013
Language English
Publisher Elsevier
Publisher location Amsterdam
Contributing office(s) Astrogeology Science Center
Description 5 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Earth and Planetary Science Letters
First page 37
Last page 41
Other Geospatial Europa
Online Only (Y/N) N
Additional Online Files (Y/N) N
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