Water has disappeared on Mars, but where would it go? – International

Before, Mars It was wet, with an ocean of water on its surface. Today, most of the planet is as dry as desert, except for the ice deposits in the polar ice caps. Where did that water go?

Part of it Disappeared in the space. Molecules Water, Driven by solar wind particles, fragmented into hydrogen and oxygen atoms, especially lighter hydrogen atoms, left the atmosphere and lost to outer space.

But according to a new study, most of the water returned to Earth and was absorbed into rocks Red planet. There it remains trapped in the midst of minerals and salts. In fact, 99% of the water may have been flowing on Mars, according to estimates by researchers at A. A study published in March in the journal Science.

Data from robotic missions to Mars from two decades ago, including those brought by the Curiosity spacecraft and the Mars Reconnaissance Orbiter, from NASA, A wide distribution of what geologists call Wet minerals.

“It was very clear that it was common, and often, to find evidence of changing water,” said Bethany Illman, a professor of planetary science at the California Institute of Technology and one of the study’s authors.

As the rocks were altered by liquid water, water molecules were incorporated into minerals such as clay, Ellman said in an interview at the Planetary and Moon Science Conference. “Water is actually trapped in the crust,” she said.

To find out the volume of water, planetary scientists speak of a “parabolic global layer”, that is, if Mars is a uniform sphere, without a distinct relief, then how deep is the water?

Scientists estimated that this depth would be from 100 to 1500 meters. Most likely it will be about 600 meters, or about a quarter of the water as it is in Atlantic Ocean.

The data and simulations also indicated that the water practically vanished three billion years ago, around this time, in TerraLife is made up of single-cell microbes in the ocean.

“This means Mars has been dry for a long time,” said Eva Schiller, a student at the California Institute of Technology and lead author of the study at UCSD. Science.

Today there is still water equivalent to a global ocean at a depth of 19 to 40 meters, but it is frozen in the polar ice caps.

Scientists have long marveled at ancient evidence of water flowing on Mars – giant canyons, dry riverbeds. NASA’s latest expedition mission, with its persevering spacecraft, which landed in February at the Jezero Crater, is aiming for a river delta in hopes of finding signs of past life.

Without a time machine, there is no way to monitor the amount of water on Mars in its youth, more than three billion years ago. But hydrogen atoms floating in Mars’ atmosphere today act as ghostly remnants of the ancient ocean.

On Earth, one out of every 5,000 hydrogen atoms is a version known as deuterium that is twice as heavy because its nucleus contains a neutron and a proton. (The nucleus of a normal hydrogen atom contains only one proton and no neutrons.)

But on Mars, the concentration of deuterium is much higher, about one in 700. Scientists at NASA’s Goddard Space Flight Center, who reported the discovery in 2015, said that this data could be used to calculate the volume of water on the planet. Mars in its early days may have had a ratio of deuterium similar to that on Earth, but the fraction of deuterium increased over time as water evaporated and hydrogen was lost in space, because heavier deuterium is less likely to escape into the atmosphere.

Renew Hu, a scientist at NASA’s Jet Propulsion Laboratory and one of the authors of the article published in, said Science, Is that Mars didn’t lose hydrogen very quickly. Measurements made by the MAVEN probe (Mars Atmosphere and Volatile Evolution) have shown that, at the current rate, spanning over four billion years, only a small fraction of the water loss will be obtained. It is not enough to explain why Mars has dried up so much. ”

This led to the new research that concluded that a large portion of the water had penetrated into the rocks.

“It’s a very interesting new study in which many processes are combined to come up with alternative scenarios for the fate of water that was on Mars,” said Jeronimo Villanueva, one of the NASA scientists who made the first deuterium measurements.

“It opens up the possibility of a wetter past on the planet and that the rocks on Mars contain more water today than we originally thought.” / Translate TEREZINHA MARTINO

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