Martian Surface May Have Been Shaped By Large And Heavy Raindrops

Heavy rainfall on the Red Planet may have carved out river-like channels and reshaped the impact craters on its surface billions of years ago, a new research has found out. Changes in the atmosphere of Mars made it pour down quite hard.

According to an IndiaTimes report, researchers Ralph Lorenz and Robert Craddock from the Johns Hopkins University found that the heavy rainfall on Mars, during the planet’s ancient past, was heavy enough to create surface changes. The study was published in the journal Icarus.

“Many people have analyzed the nature of rainfall on Earth, but no one had thought to apply the physics to understanding the early Martian atmosphere,” Craddock said, according to Space.com. The researchers analyzed how the atmosphere of the Red Planet has changed to understand how the rainfall has altered there.

Mars had a much more substantial atmosphere, with a higher pressure 4.5 billion years ago, than it does now. The high pressure influenced the raindrop size and how hard it fell. During that period, the water droplets would have been tiny, creating more of a fog-like effect rather than actual rainfall. This type of rain would not have had the ability to carve out the surface features on the Red Planet.

The raindrops gradually became heavier and bigger as the atmospheric pressure decreased over millions of years. Subsequently, the rain was strong enough to dig into the soil and change the craters, gradually cutting through the surface of Mars and creating valleys.

“By using basic physical principles to understand the relationship between the atmosphere, and raindrop size and rainfall intensity, we have shown that Mars would have seen some pretty big raindrops that would have been able to make more drastic changes to the surface than the earlier fog-like droplets,” Lorenz added.