Martian volcano erupted continuously for 2 billion years

Scientists have uncovered evidence of at least two billion years of volcanic activity on Mars, after analysing a meteorite from the red planet. Discovered in 2012, the 6.9-ounce meteorite known as Northwest Africa 7635 was found to be a type of volcanic rock called a shergottite.

Martian meteorite "Northwest Africa 7635," discovered in Algeria in 2012, has allowed an international team of scientists to gain new insights into the geologic history of Mars.

The finding confirms that some of the longest-lived volcanoes in the solar system may be found on the red planet.

Shield volcanoes and lava plains formed from lava flowing over long distances, similar to the formation of the Hawaiian Islands.

As of now, the exact origination of the meteorite is unknown but fingers are pointing at the largest Martian volcano, Olympus Mons, which is nearly 27.3 kilometres high. That is almost triple the height of Earth's tallest volcano, Mauna Kea, at 10 kilometres.

"We don't know at this point where this particular meteorite came from, whether it was Olympus Mons or some other location," said Marc Caffee, professor of physics and astronomy at Purdue University.

The findings offer new clues to how the planet evolved and insight into the history of volcanic activity on Mars, said Tom Lapen, a professor at the University of Houston in the US.

Much of what we know about the composition of rocks from volcanoes on Mars comes from meteorites found on Earth.

Interestingly, most Martian meteorites are found in Antarctica or North Africa.

"Between Antarctica and other deserts we add more than 1,000 meteorites per year, but only a few of those are interesting, including those originating from Mars and the moon," said Caffee. 

Analysis of different substances provides information about the age of the meteorite, its magma source, length of time in space and how long the meteorite was on Earth's surface.

Something slammed into the surface of Mars one million years ago, hitting a volcano or lava plain. This impact ejected rocks into space. Fragments of these rocks crossed Earth's orbit and fell as meteorites.

The findings conclude that NWA 7635 was found to be 2.4 billion years old, more than half of the Mars' 4.5 billion-year history.

NWA 7635 is one of eleven Martian meteorites that share similar chemical composition and ejection time.

"We see that they came from a similar volcanic source. Given that they also have the same ejection time, we can conclude that these come from the same location on Mars," said Lapen.

Together, these meteorites provide information about a single location on Mars. Previously analysed meteorites range in age from 327 million to 600 million years old.

In contrast, the 2.4 billion years ago meteorite suggests that it was ejected from one of the longest-lived volcanic centres in the solar system.

The study was published in the journal Science Advances.

(With Agency Inputs)