The Roots of Anomalous Radar Observations of Ocean Worlds

LASP Science Seminars

The Roots of Anomalous Radar Observations of Ocean Worlds

October 20, 2022
4:00 PM MT/MST

Radar properties of icy satellites of Jupiter and Saturn are extraordinary, many differ by more than an order of magnitude from those of rocky planets. We demonstrate that two icy-satellite radar properties are correlated and together they vary along a spectrum. Thus, those properties are better described as ranging within a distribution that includes very high extremes, than as an anomalous group. All six previously published models to explain the extraordinary icy-satellite radar properties fail to satisfactorily fit this new constraint. However, one model, with a modest adaptation, successfully fits the observed spectrum. Anomalously specular radar reflections (ASRR), different from the extraordinary radar properties of other icy satellites, were observed from Saturn’s moon Titan with the Arecibo Observatory (AO) and Green Bank Telescope (GBT) and interpreted as evidence for liquid surfaces. The Cassini spacecraft discovered lakes/seas on Titan, however, it did not observe lakes/seas at the AO/GBT ASRR locations. We show that the ASRR originate from one terrain unit, likely paleolakes/paleoseas.

Upcoming Science Seminars:
Dec. 8, 2022
ARM Value-added Products: A Community Resource for Atmospheric and Climate Model Research
Damao Zhang
(Pacific Northwest National Laboratory)