BBC Science Focus

SOMETHING’S RUMBLING ON THE RED PLANET

Mounting evidence suggests Mars isn’t dead

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Volcanoes on Mars could’ve erupted as recently as 50,000 years ago, a study carried out by researcher­s at the University of Arizona using data from satellites orbiting the planet has found.

Previous studies have suggested that most of Mars’s volcanic activity occurred between three and four billion years ago, with some outlying eruptions continuing in isolated locations until about three million years ago.

“This may be the youngest volcanic deposit yet documented on Mars,” said lead author Dr David Horvath, who worked on the study as a postdoctor­al researcher at the University of Arizona and is now a research scientist at the Planetary Science Institute. “If we were to compress Mars’s geologic history into a single day, this would have occurred in the very last second.”

The volcanic deposit was found in Elysium Planitia, a smooth, flat plain located just north of the equator. The eruption produced an 11km-wide, smooth, dark deposit surroundin­g a 32km-long volcanic fissure, and could have spewed ash and rock up to 10km into the Martian atmosphere. The compositio­n and distributi­on of the material deposited is similar to what would be expected for a pyroclasti­c eruption – an explosive eruption of magma driven by expanding gases, similar to what happens when you open a bottle of sparkling wine.

Some hallmarks of the volcanic deposit also raise the possibilit­y of there being conditions capable of supporting microbial life below the surface of Mars.

“The interactio­n of ascending magma and the icy substrate of this region could have provided favourable conditions for microbial life fairly recently and raises the possibilit­y of extant life in this region,” Horvath said.

The site of the eruption is around 1,600km from NASA’s InSight lander, which has been studying seismic activity on Mars since 2018.

Further study is required to determine the exact nature of the eruption, but two marsquakes (the Martian equivalent of earthquake­s) were found to originate around the Cerberus Fossae system of fissures in Elysium Planitia. Recent work has suggested the fissures could be due to movement of magma deep undergroun­d.

“The young age of this deposit absolutely raises the possibilit­y that there could still be volcanic activity on Mars and it’s intriguing that recent marsquakes detected by the InSight mission are sourced from the Cerberus Fossae,” Horvath said.

The eruption may also have been due to a build-up of gases already present in the magma, or could have happened when the magma came into contact with permafrost, according to the researcher­s. It’s also possible that the eruption was triggered by the asteroid impact that formed the nearby Zunil crater at about the same time.

The volcanic deposit, along with ongoing seismic rumbling in the planet’s interior detected by InSight, and possible evidence for releases of methane into the atmosphere detected by NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN) orbiter, suggest that Mars is far from a cold, inactive world.

“This may be the most recent volcanic eruption on Mars, but I think we can rest assured that it won’t be the last,” said study co-author Jeff Andrews-Hanna, an associate professor at the University of Arizona Lunar and Planetary Laboratory. “All these data seem to be telling the same story – Mars isn’t dead.”

“The interactio­n of ascending magma and the icy substrate of this region could have provided favourable conditions for microbial life”

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 ??  ?? Elysium Planitia on Mars could have experience­d volcanic activity in the last 50,000 years
Elysium Planitia on Mars could have experience­d volcanic activity in the last 50,000 years

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