Satellite imaging wasn’t enough for Sheridan Ackiss, a PhD student in the
Department of Earth, Atmospheric, and Planetary Sciences.
Ackiss followed up her internationally recognized, NASA-backed findings on
Mars’ ancient volcanic history with a trip to study the volcanoes of Earth.
By studying images retrieved from NASA’s Mars Reconnaissance Orbiter’s
mineral-mapping spectrometer, Ackiss and her team found evidence for volcanoes
in a southern region of the Red Planet known as Sisyphi Montes. Different types
of rocks cover the volcanoes, and her research suggests the rocks tell a story of
volcanic eruptions beneath a sheet of ice. For NASA, this volcanic and icy history
could help reveal more about past Martian climate and the history of its potentially
But getting to see Mars’ ancient, under-ice volcanoes up close is out of the
question, at least for a long time. Ackiss decided to take a trip to Ecuador to compare
and contrast the Mars volcanoes she is researching from afar with some of Earth’s
most active volcanoes within the majestic Andes Mountains.
“I think volcanic processes and behaviors are the same on both planets,” says
Ackiss, who works in EAPS professor Briony Horgan’s laboratory and is a NASA
Earth and Space Science doctoral fellow.
Ackiss, fellow EAPS graduate student Marie McBride and students from other
universities joined the South Dakota School of Mines’ Volcanology Field Camp to
put on their hiking boots, grab their hammers, and investigate lava flows, compositions, deposits and the surrounding rocks of Ecuadorian volcanoes from May 17
to June 3. While her South Dakotan peers concentrated on Earth stones, Ackiss
was still thinking of the Martian minerals.
“I wanted to go and see the deposits firsthand to know what I’m looking at on
Mars,” says Ackiss, who worked for NASA’s Goddard Space Flight Center before
arriving at Purdue. “We can’t look at images from Mars and say ‘This is a layer of
pumice followed by a layer of dirt’ mostly because it’s not that definitive. As plan-
etary scientists, we have to look at all possible angles to verify what we think we
are seeing. Everything has to be non-interpretive. So, we would say something
like, ‘This is a light-toned layer followed by a dark-toned layer.’”
Ecuador, which is about the size of Colorado, has tremendously diverse terrain
— rainforest, mountains, beaches and islands. Fortunately for Ackiss, volcanoes
touch all of these Ecuadorian regions. Ackiss conducted field work at the freezing
Tungurahua and Cotopaxi ( 5,900 meters above sea level) stratovolcanoes in the
Andes Mountains, and Galapagos Islands’ shield volcanoes.
“It was an amazing learning experience for me,” Ackiss says. “It’s made me
really rethink things for my research. For Mars, we look at things from the 5- to
10- to 50-kilometer scales. On Earth, it’s a centimeter scale.”
Horgan and Ackiss are part of the upcoming NASA Mars 2020 rover mission.
Horgan has worked on the science team for the $2.5 billion rover’s camera since
Mars research likely will remain an important part of the planetary sciences
program as NASA, and millions of planetary science fans consistently
have one eye on the Red Planet.
Since the region of Mars that Ackiss studies is near the
planet’s south pole, it’s much too cold, treacherous and remote
for a rover to land. NASA is banking on researchers like Ackiss
to reveal as much as they can about Earth’s neighbor. The
Sisyphi Montes will be inaccessible for many years.
“We’re sending rovers. We’re trying to get samples
returned and we’re trying to send humans,” Ackiss says.
“I think my research is interesting because it’s not accessible to the rovers or the landing sites. We learn so much
from the rovers but we learn about planetwide processes thanks to the satellites.”