For a long time, scientists have been studying the likelihood of a liquid water source on Mars. Previously, researchers believed that Mars’s southern polar ice caps stored liquid water – as per a 2018 study. However, recent studies have shown little chance of such an instance.
In a 2018 paper published in the journal Science, radar signals aided the scientists to discover a high radar reflective spot that lay around 0.90 miles below the ice. The researchers believed this patch to be an underground pool of liquid water. In a later 2020 study as published in the journal Nature Astronomy, scientists further suggested that there could be a complete underground network of lakes with liquid water. They further hinted that such lakes could support organisms that do not need sunlight to grow.
However, scientists have concluded that Mars is too cold to hold liquid lakes.
In a recent paper published, it was discovered that the temperatures on the planet were shallow, and therefore it has significantly less chance of holding unfrozen water on it. In another study by scientists from the University of Texas and the University Grenoble Alpes, it was discovered that the signals that were previously assumed to be liquid water could perhaps be volcanic rock – a feature that is present in abundance on the planet.
In a 2021 study published in Geophysical Research Letters, the scientists discovered that similar signals were observed while studying the frozen clay structures on Mars. In the latest 2022 study published in the same journal, the researchers concluded that the reflective patches previously assumed to be water bodies matched the volcanic terrain. Further remote sensing work will help confirm whether or not frozen clay structures are the culprit.