The water on Mars disappears. This is probably where he went.

“This means Mars has dried up for a very long time,” said Eva Schiller, a graduate student at the California Institute of Technology and lead author of the science paper.

Today, there is still water equivalent to a global ocean that is 65 to 130 feet deep, but most of it is frozen on the polar ice caps.

Planetary scientists have long admired ancient evidence of water flows etched into the surface of Mars – giant canyons, winding river channel solutions, and deltas as rivers push sediment into lakes. Persistence is NASA’s newest Mars rover robotIt landed in the last month Crater lake, You will head to the river delta on its banks hoping to find signs of a past life.

Without a time machine, there is no way to monitor how much water was on Mars that was younger than three billion years ago. But the hydrogen atoms floating today in the Martian atmosphere retain some of the shadow of the ancient ocean.

On Earth, about one in every 5,000 hydrogen atoms is the version known as deuterium and is twice as heavy because the nucleus contains neutrons and protons. (The nucleus of a typical type of hydrogen atom contains only one proton, and no neutrons.)

But on Mars, deuterium concentrations are significantly higher, about one in 700. Scientists at NASA’s Goddard Space Flight Center I reported this result in 2015 He said this could be used to calculate how much water is on Mars. Mars may have started with a deuterium to hydrogen ratio similar to Earth’s, but the deuterium fraction increases over time as water evaporates and hydrogen is lost in space, because heavier deuterium tends not to escape from the atmosphere.

The problem with this story is that Mars doesn’t lose hydrogen fast enough, said Renew Hu, a scientist at NASA’s Jet Propulsion Laboratory and another author of the current scientific paper. Dr Hu said NASA’s measurements of Mars’ atmosphere and the evolution of its fluctuating orbits, or mavens, show that the current rate, which was extrapolated over four billion years, “could represent a fraction of water loss.” “It’s not enough to explain how dry Mars is.”

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