Cornell University researchers have debunked the theory of liquid water beneath the ice cap on Mars’ south pole. Their simulations showed that small variations in layers of water ice can cause constructive interference between radar waves, leading to bright radar reflections. These reflections were initially interpreted as liquid water, but the researchers proved that they could be explained by ice composition and layer thickness variations. The reflections were consistent with observations across the south polar layered deposits, and did not necessarily indicate the presence of liquid water.
The discovery of a potential subglacial lake on Mars was made by the European Space Agency-led Mars Express orbiter’s science team in 2018. The presence of liquid water would have significant implications as it could potentially support microbial life. However, the researchers at Cornell University argued that while similar bright radar reflections on Earth would indicate a subglacial lake, the conditions on Mars are inherently different. The temperature and pressure conditions on Mars would not support the existence of liquid water beneath the ice cap, despite previous assumptions made about layers of frozen carbon dioxide.
The research conducted by Daniel Lalich and his team at Cornell University used more realistic modeling to support their hypothesis that the bright radar reflections can be explained without the need for liquid water. By generating thousands of layering scenarios based on conditions known to exist at the Martian poles, they were able to show that variations in ice composition and layer spacing could create the observed radar signals. The reflections were consistent with observations made by the Mars Express orbiter’s MARSIS radar instrument, indicating that radar waves bouncing off closely spaced layers can result in amplified peaks and troughs.
The researchers at Cornell University suggest that the story of liquid water and potential life on Mars may have ended long ago. While they do not completely rule out the potential for future detection of liquid water by more advanced instruments, they believe that the current evidence does not support the presence of liquid water near the surface of Mars. The research was supported by NASA, and their findings provide a simpler explanation for the bright radar reflections observed below the ice cap on Mars’ south pole.
In conclusion, the research conducted by Cornell University researchers challenges the initial interpretation of bright radar reflections as indicating the presence of liquid water beneath the ice cap on Mars’ south pole. They propose that small variations in ice composition and layer thickness can create constructive interference between radar waves, producing reflections that mimic the observed signals. While the discovery of liquid water on Mars would have been groundbreaking, the researchers suggest that the conditions on the red planet do not support the existence of liquid water near the surface. Their findings provide a more comprehensive and realistic explanation for the radar reflections observed by the Mars Express orbiter’s MARSIS radar instrument.