Recent research has revealed that the mysterious subsurface lakes discovered on the red planet aren’t really “lakes” but “smectites”, a class of heavily found clays on Mars, reports Gizmodo.
The Study Research around the same has been published in a study in the Geophysical Research Letters. It explains, “According to the Mars Advanced Radar for Subsurface and Ionosphere Sounding instrument, bright radar reflections beneath the south polar layered deposits (SPLD) point to the presence of liquid water, however, given what is known about Mars, it is unlikely that liquid water could exist here.”
The paper makes the hypothesis that these bright reflections misinterpreted in the data are indeed “hydrated and cold clay-rich deposits” at the base of the SPLD create the detected radar response.
“I really don’t think that the lake idea holds water, so an alternative was needed … smectites are teeming on Mars and heavily studied by spectroscopists, but they’ve been mostly neglected by the radar community. My hope is that we analyze them more fully in the future and even revisit some of our previous work in light of these new results,” Isaac Smith, a planetary scientist at York University and lead author of the new study paper, told Gizmodo over an email.
The study presents experimental measurements and waves propagation modelling that shows that “smectites”, cooled to 230 K, have parts of the dielectric permittivity that’s big enough to result in bright reflections.
Moreover, the study reveals that absorptions attributable to these minerals are detected in south polar orbital visible-near-infrared reflectance spectra. According to the research paper, because these minerals are present at the south pole and can cause reflections, we believe this is a more viable hypothesis than liquid water.