Scientists say they’ve discovered why Mars is red бот лаки джет

With its iconic rusty hue, Mars has long been called the red planet. Now, scientists may have discovered the potential source of that distinctive coloring, overturning a popular theory in the process.

Mars is one of the most well-studied planets in our solar system due to its proximity to Earth and the numerous spacecraft that have visited over the past few decades. Together, orbiters and landers have provided scientists with data showing that Mars’ red color comes from rusted iron minerals within the dust that coats the planet.

At some point, iron within rocks on Mars reacted with water or water and oxygen in the air, creating iron oxide — much in the same way rust forms on Earth. Over billions of years, the iron oxide broke down into dust and settled across the planet after being moved by Martian winds, which still spins up dust devils and massive dust storms.

Previous analyses of iron oxide on Mars, based only on observations by spacecraft, didn’t detect any evidence of water, which led researchers to believe that the iron oxide must be hematite. The dry mineral, a main component of iron ore, was thought to have formed through reactions with the Martian atmosphere in a process that occurred over billions of years. If that was the case, the hematite would have formed later in Mars’ history, after it was suspected of hosting lakes and rivers on its surface.
New research combining data from multiple missions and replicated Martian dust has suggested a mineral that forms in the presence of cool water may be responsible for the red hue, rather than hematite, which could change the way scientists understand what Mars was like millions of years ago — and whether it was potentially habitable. A team of scientists reported the findings Tuesday in the journal Nature Communications.

“Mars is still the Red Planet,” said lead study author Adomas Valantinas, a postdoctoral fellow in the department of Earth, environmental and planetary sciences at Brown University, in a statement. “It’s just that our understanding of why Mars is red has been transformed.”