Just 20 million years after the solar system formed, the Red Planet already had its outer shell
Mars was a fully formed planet — crust and all — within just 20 million years of the solar system’s birth. That rapid formation means the Red Planet probably got a 100-million-year jump on Earth in terms of habitability, new research suggests.
Geochemical analyses of crystals of the mineral zircon extracted from Martian meteorites reveal that Mars had formed its earliest crust by 4.547 billion years ago, scientists report June 27 in Nature. That’s just 20 million years after the disk of gas around the sun gave birth to the solar system’s planets.
The emergence of a planet’s outermost shell, or crust, is the final stage in the formation of terrestrial planets like Mars, Earth, Venus and Mercury. The process begins with the accretion of particles from the protoplanetary gas disk; eventually, those particles form molten material that makes up a hot magma ocean. As