Secrets of the Soaring Martian Mounds: Echoes of Ancient Waters

What are the mounds on Mars comprised of?

In order to explore the geology of the mounds, Joe utilized images captured by NASA and ESA satellites presently orbiting Mars. These orbiters are equipped with various cameras, spectrometers, and sensors that can be utilized in tandem to comprehend different facets of the planet’s geology.

“Every mound consists of a succession of layers, each serving as a record of a historical event,” explains Joe. “The oldest layers are at the base and comprise rock aged around four billion years. For a geologist, examining these layers resembles flipping through the pages of a book – each layer narrates a story!”

“The mounds encompass up to 350 meters of clay-rich rock, indicating that an abundance of water must have existed on the surface for an extended period. It is conceivable that this could have originated from an ancient northern ocean on Mars, although this concept remains contentious.”

The presence of water on Mars’s surface initiated chemical reactions with the rocks, resulting in the formation of clay-rich sediment in the highlands. Over time, these highland regions eroded at their peripheries, leaving the mounds behind. The exact duration of this process is currently challenging to determine.

“Accurately dating regions of the planet without samples for laboratory testing is quite challenging,” Joe clarifies. “Instead, we count craters. We can infer that locations with a higher density of craters are older, while areas with fewer craters are likely younger.”

“I estimate that this process spanned between 100-200 million years. This might suggest that the sediment accumulated rapidly and then eroded gradually, or the other way around.”

To further refine these dates, it would be necessary to bring Martian samples to Earth, an endeavor currently in the planning stages but not anticipated until the 2030s. By learning more about Mars, Joe elaborates, we can also gain insights about Earth.

“Mars serves as a model for what early Earth may have looked like, as its absence of plate tectonics ensures that Mars’s ancient geology remains intact,” he states. “Studying early Mars enhances our understanding of early Earth, and as additional missions explore the red planet, the more in-depth we can delve into our own planet’s history.”