Mars has achieved its complete planetary form within just 20 million years after the sun was born. This suggests Mars has become habitable much earlier than Earth.
Specifically, the Red Planet had its fully hardened and possibly habitable outer crust about 4.547 billion years ago or approximately 100 million years before Earth becomes habitable according to a new study.
From Dust To Actual Planet
The final stage before any terrestrial world can become actual planets is the hardening of their outermost shell or crust. This process first involves the accumulation of particles originating from the protoplanetary gas disk. The accumulated particles will then become molten materials and will afterward become an ocean of hot magma. As this magma cools and crystallizes, it becomes solid and forms a metallic core until finally becoming the planet's crust.
It was previously thought that all terrestrial planets undergo this whole process 30 million to as long as 100 million years.
Now, a new study found that Mars' crust hardened more rapidly compared to its counterparts. This new information can revise the entire timeline of the Red Planet's early stages. Additionally, the new insight is important for understanding the planetary history of all other rocky planets in the solar system.
Timeline Of Mars' Crust Formation
The new findings, published in the journal Nature on June 27, specified that Mars achieved its current size approximately within less than 100 million years after the formation of the first solids in the gas disk around the sun. The formation of these first solids, which were identified as calcium-aluminum-rich inclusions, around the sun took 4,567.3 million years.
About 20 million years after the formation of the first solids around the sun, Mars partially melted to produce magmas that ascended to its surface. About 70 million years more, these molten magmas solidified to become the planet's crust.
"To put these timescales into perspective, if the Solar System were one day old, Mars would have fully formed in the first 6 minutes," wrote Linda Elkins-Tanton, a planetary scientist at Arizona State University.
"Therefore, in the astonishingly short interval of 90 [million years], Mars grew from dust to a planet, solidified from its initial magma-ocean state and formed a crust containing zircons," Elkins-Tanton explained.
To achieve their new calculation of Mars' early formation, the scientists, led by Laura Bouvier from the University of Copenhagen analyzed the zircons extracted from a meteorite known as Black Beauty.
Black Beauty, the Martian meteorite found in the Saharan Desert in 2011, weighs 320 grams. Bouvier's team was able to analyze 44 grams of Black Beauty, of which 5 grams were crushed into particles enough to extract seven bits of zircons.
As mentioned, Mars' molten magma during its early stages contains these zircons. Hence, by being able to examine these zircons, the scientists were then able to calculate a revised timeline of the actual Mars' crust formation.