Red Planet’s blue secret: Mars hides vast underwater world miles before surface

The barren, hostile Mars likely harbors a surprisingly massive hidden reservoir of water trapped deep within its crust.

This intriguing find comes from the data collected by NASA’s long-dead InSight lander. Interestingly, this underground reservoir is estimated to be large enough to cover the entire planet in a mile-deep layer of water.

A Scripps Institute of Oceanography-led team of experts studied seismic data obtained by the lander from Martian innards.

“If we take all the mid-crust water and cover the surface of Mars, the liquid water would fill a 1-2 km deep ocean on Mars. The diameter of Mars is only half of Earth’s,” Vashan Wright, the lead author of this study, told Interesting Engineering (IE).

Billions of years ago, the Martian landscape was totally different from what we see today. Dried-up riverbeds and lake basins provide rich evidence of this wet history.

Wright added: “Liquid water existed on the surface of Mars early in its history. On Earth, groundwater underground infiltrated from the surface, and we expect this to be similar to the history of water on Mars.
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Interestingly, the amount of water locked beneath Mars’ dusty surface could be more than its postulated ancient oceans.

Water locked deep beneath Martian surface

In 2022, NASA revealed that its stationary lander had stopped working due to dust accumulation on its solar panels.

During its four years of operation, the lander gathered a wealth of data, which is currently leading to unexpected findings.

The seismometer aboard InSight detected the planet’s vibrations. Scientists studied these data to establish how the speed of seismic waves varies with depth.

Through this, they were able to discern that the first five kilometers of Mars’ upper crust seemed to be dry. However, evidence points to a water-filled zone of cracked rock between 11.5 and 20 kilometers underground.

“The speed of seismic waves depends on properties of rocks – what they are made of, are they cracked, what fills the cracks. Gravity data was previously available for Mars. A mid-crust whose rocks are cracked and filled with liquid water best explains both seismic and gravity data,” added Wright.

To corroborate its findings, the team used a mathematical model of rock mechanics, similar to those used on Earth to locate aquifers and oil reserves.

Sample return mission may bolster this find

Planetary scientists believe ancient Mars was warmer and had a thicker atmosphere, allowing liquid water to exist on the surface.

However, Mars eventually lost its atmosphere and became the barren desert we know today.

Much of Mars’ water is now locked up in polar ice caps . However, this latest study’s findings show that some water did manage to trickle down into the crust.

“We confirmed that much of Mars’ water was not lost to space, and is stored as groundwater. It would be nice to figure out when and how the water got there,” mentioned Wright.

The researchers have great expectations that the Mars sample return mission will be able to strengthen this evidence.

He told IE: “The Perseverance Rover is collecting samples to be returned to Earth. These will tell us a lot about the history of water on Mars and even more about the geological history.”

While this discovery is exciting, the water is locked deep beneath the surface. This implies it will be unreachable for possible human exploration until some cutting-edge technology emerges, like as borewell drilling on Earth.

Nevertheless, the study offers valuable insights into Mars’ geological history and enhances the prospect of finding life in this underground environment.

The findings were reported in the journal Proceedings of the National Academy of Sciences.