Mars has lost a staggering amount of water over its 4 billion-year lifetime, leaving scientists puzzled about how it happened. A new study suggests that the planet’s wildly varying tilt may be the key to solving this mystery.
The Red Planet’s rotational axis has oscillated between 0 and 66 degrees in the past few million years, unlike Earth which stabilizes at around 23.5 degrees. This instability caused by the lack of a massive satellite like the Moon allows Mars’ axis to tilt more dramatically, resulting in more sunlight reaching its poles.
As a result, scientists believe that increased temperatures would have melted ice and led to the loss of atmospheric hydrogen. The study’s authors used a computational simulation to model the effects of these changes, revealing that at a 35-degree tilt, an average of 19 more hydrogen atoms escape from Mars’ atmosphere every second.
This translates to a Martian yearly loss of a billion more hydrogen atoms, equivalent to a global layer of water about 260 feet thick. The findings support the idea that the planet’s atmospheric thermal escape played a larger role in drying it out than previously thought.
However, the researchers acknowledge that other factors, such as the planet’s dust composition, may have also contributed to the water loss. Further studies are needed to confirm this hypothesis and understand the complex processes at play on Mars.
Source: https://www.livescience.com/space/mars/mystery-of-mars-missing-water-could-be-solved-by-the-planets-tipsy-tilt