Image courtesy ASU/GSFC/JPL/NASA
Published October 2, 2013
Massive "supervolcanoes" erupted across the northern face of Mars some 3.7 billion years ago, planetary scientists suggest. The eruptions likely blasted lava, sulfur, and ash across the red planet, altering its atmosphere and surface.
The planets of the inner solar system—Earth, Mars, Venus, and Mercury—started their lives as boiling-hot balls of rock, which cooled to feature thin crusts battered by asteroid and comet impacts. On Mars, that early crust was perhaps also punctured by supersize volcanoes with calderas more than 30 miles (50 kilometers) wide, a newly identified kind of volcanism on the red planet. (See "Mars: The Red Planet.")
"We began to find craters that weren't impact craters. So we started to wonder if what we were seeing was volcanic," says Joseph Michalski of the Planetary Science Institute in Tucson, lead author of the study, published today in Nature. "We can make a strong case that these were a kind of very large volcano."
Mars is already known for its volcanic features, notably Olympus Mons, a dormant volcano some 14 miles (22 kilometers) tall and 370 miles (600 kilometers) wide, the largest volcanic mountain in the solar system. (See "New Giant Volcano Below Sea Is Largest in the World.") However, the newly identified supervolcanoes would point to an early era on Mars when volcanic pools spread across its surface like fuming, open wounds.
In the study, Michalski and his colleague, Jacob Bleacher of NASA's Goddard Space Flight Center in Greenbelt, Maryland, analyzed orbital images of the Arabia Terra highlands of northern Mars, reporting signs of at least four massive supervolcanoes stretching across the 2,800-mile (4,000-kilometer) plain.
These were not the familiar shield volcanoes, or mountains tipped by a narrow crater, that are widely seen on Earth and Mars, but broad depressions some 1.1 miles (1.8 kilometers) deep. These broad open plains of magma once would have vented massive amounts of ash and steam to the sky. The closest comparison on Earth might be the broad volcanic caldera beneath Yellowstone National Park, which has erupted three times over the last 2.1 million years.
"We think they would have had a profound effect on the early Martian atmosphere; we're talking more than three billion years ago," Michalski says.
The scientists point to basalt blocks and smooth lava plains surrounding the supervolcanoes that resemble those of caldera features on Earth to make their argument. Evidence from NASA's rover Opportunity shows that the Meridani Planum region of Mars is a broad plain suffused with sulfur that resembles the volcanic fallout that would be seen from supervolcanoes as well, Michalski says.
"Every decade or two someone proposes yet another otherwise previously unrecognized volcano on Mars," says space volcanology expert Larry Crumpler of the New Mexico Museum of Natural History and Science in Albuquerque. He calls the supervolcano "an interesting new idea about Martian highlands volcanism where none had been proposed before."
However, both Crumpler and MIT's Maria Zuber (who calls the observations "well supported") caution that the supervolcanoes idea rests on interpretation of the Martian surface, which has a long history of misleading observers.
"Like most remote-sensing studies it relies principally on circumstantial evidence," Crumpler says. "Nonetheless, it postulates an intriguing direction for future research regarding what was the wettest period in Martian geologic history."
Wetter, Warmer Mars
The effect of greenhouse gases released by these supervolcanoes particularly intrigues Michalski, offering an avenue for investigating how warm Mars was in the early years of the solar system. Although warmer and wetter than today, the era of the supervolcanoes was likely still too early to figure in discussions of life on Mars, he adds. "A lot of people want to look at this from the 'life on Mars' angle, but I don't think that's what is important here," he says.
Zuber says that the supervolcanoes, if they do prove to have once littered the red planet, will only add to the picture that scientists have of the early Martian atmosphere. The massive Tharsis region of Mars, home to Olympus Mons and several other large dormant volcanoes, already has been accounted for in ancient climate studies, Zuber says, "so these [supervolcano] observations do not substantially modify the view of the planet's climatic evolution."
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That life existed on Mars is highly proable but was destroyed when a catestrophic event took place destroying the magnetic field protection which allowed the removal of atmosphere. This life may have been far superior than ours is today and some may have escaped the planet and landed on earth. Cave pictures depict humans wearing astronomic clothing and ancient gold figures that represent space vehicles. These individuals may have genetically altered humans through interalien relations. In short, humans may very well be Martians. Only time will tell, especially when our science advances, and scientists expanding egos return to reason. Of course this assumes that the super volcano at Yellowstone National Park does not destroy us first.
@El Gabilon "interalien" isn't a word as far as I can tell but the idea of swapping fluids with an extraterrestrial is exciting nevertheless especially if they are outfitted in a kinky, sadistic "astronomic" outfit.
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