Mars is believed to have had rivers and lakes of liquid water that disappeared about 3.5 million years ago. NASA researchers have now figured that the culprit behind disappearance of water on the red planet. They think an unusual dust elevator that carried all the water to space.
Scientists analyzed data collected by NASA’s Mars Reconnaissance Orbiter (MRO) during the 2018 global dust storm that ended the Opportunity rover’s mission. Dust storms are common on the Martian surface but sometimes the whole planet is enveloped in dusty storm systems dubbed as Global Dust Storm.
Within the storms, a phenomenon known as dust towers has been observed. Dust towers are concentrated clouds of dust that rise from the surface into the thin Martian atmosphere when heated by sunlight. NASA says on subsiding, the phenomenon leaves behind a 56 kilometers thick layer of dust that is as wide as the continental United States.
Using the heat-sensing Mars Climate Sounder instrument and Mars Context Imager (MARCI) aboard the MRO researchers detected multiple dust towers. The researchers published two papers from their study. They observed that towers would last for over three weeks in global dust storms, much longer than normal dust storms.
The researchers think that these dust towers can act like ‘space elevator’ that carries materials from the surface to the atmosphere. The dust in the atmosphere creates an updraft on heating up carrying gas and small quantity of water vapor.
In a previous paper, researchers described how water molecules could be carried by dust storms to upper atmosphere where solar radiation breaks them down. The researchers think this explains how the red planet became a freezing desert and hope to figure out more with more data as they have only studied a dozen dust storms.
Mars Climate Sounder scientist David Kass of JPL explained: “We really don’t have anything like this on the Earth, “Global dust storms are really unusual, where the entire planet’s weather changes for several months.”