Andrew Masterson
Andrew Masterson is a former editor of Cosmos.
Mars has long been
considered a geologically inert planet, silent and still since the massive
volcanic eruptions that fashioned much of its surface ended more than three
billion years ago.
However, new findings
derived from images obtained by the Mars Orbiter
Camera aboard the Mars Global Surveyor Mission have raised the intriguing
possibility that lava may one day soon flow fresh across the Red Planet.
A team led by geology
and geophysics graduate researcher David Susko, from the Louisiana State
University, focused on a Martian volcano dubbed Elysium, the second highest on
the planet and more than twice as high as Everest. The findings are published
in Nature Scientific Reports.
Combining the
satellite imagery with data acquired by the Mars Rover, Susko’s team determined
that parts of Elysium’s lava deposits were only three to four million years
old, three orders of magnitude younger than the lava laid down by Mar’s other
volcanoes.
The data also
revealed that Elysium’s more recent deposits were very low in thorium and
potassium when compared to the levels present around other volcanoes and in
non-volcanic sections of the planet’s crust. The paper terms the finding a “major
depletion”.
The reasons for
the big drop in these two radioactive elements remains unknown, but the team
speculate that it may be evidence that Mar’s more recent eruptions have
differed chemically from older ones.
If so, write
the researchers, it’s a conclusion with “major implications for the history of Martian mantle
evolution, such as how volcanic provinces were built up over time, and
motivates future investigations into this province.”
Commenting on
the observation that Elysium had erupted much more recently than the planet’s
other volcanos, Susko says that in geologic terms, three million years is “like
yesterday”.
“At
least, we can’t yet rule out active volcanoes on Mars,” he adds.
“Which is very exciting.”
