Brief presence of water in Arabia Terra on Mars
Team studied thermal inertia to understand how rock layers were formed


Date:
November 30, 2021
Source:
Northern Arizona University
Summary:
Scientists recently discovered that water was once present in a
region of Mars called Arabia Terra.



FULL STORY ==========================================================================
As part of a team of collaborators from Northern Arizona University
and Johns Hopkins University, NAU PhD candidate Ari Koeppel recently
discovered that water was once present in a region of Mars called
Arabia Terra.


========================================================================== Arabia Terra is in the northern latitudes of Mars. Named in 1879 by
Italian astronomer Giovanni Schiaparelli, this ancient land covers
an area slightly larger than the European continent. Arabia Terra
contains craters, volcanic calderas, canyons and beautiful bands of
rock reminiscent of sedimentary rock layers in the Painted Desert or
the Badlands.

These layers of rock and how they formed was the research focus for
Koeppel along with his advisor, associate professor Christopher Edwards
of NAU's Department of Astronomy and Planetary Science along with Andrew
Annex, Kevin Lewis and undergraduate student Gabriel Carrillo of Johns
Hopkins University.

Their study, titled "A fragile record of fleeting water on Mars," was
funded by the NASA Mars Data Analysis Program and recently published in
the journal Geology.

"We were specifically interested in using rocks on the surface of
Mars to get a better understanding of past environments three to four
billion years ago and whether there could have been climatic conditions
that were suitable for life on the surface," Koeppel said. "We were
interested in whether there was stable water, how long there could have
been stable water, what the atmosphere might have been like and what
the temperature on the surface might have been like." In order to get
a better understanding of what happened to create the rock layers, the scientists focused on thermal inertia, which defines the ability of a
material to change temperature. Sand, with small and loose particles,
gains and loses heat quickly, while a solid boulder will remain warm
long after dark.

By looking at surface temperatures, they were able to determine the
physical properties of rocks in their study area. They could tell if
a material was loose and eroding away when it otherwise looked like it
was solid.

"No one had done an in-depth thermal inertia investigation of these really interesting deposits that cover a large portion of the surface of Mars," Edwards said.

To complete the study, Koeppel used remote sensing instruments on orbiting satellites. "Just like geologists on Earth, we look at rocks to try to
tell stories about past environments," Koeppel said. "On Mars, we're a
little bit more limited. We can't just go to a rock outcrop and collect
samples -- we're pretty reliant on satellite data. So, there are a handful
of satellites orbiting Mars, and each satellite hosts a collection of instruments. Each instrument plays its own role in helping us describe the rocks that are on the surface." Through a series of investigations using
this remotely gathered data, they looked at thermal inertia, plus evidence
of erosion, the condition of the craters and what minerals were present.

"We figured out these deposits are much less cohesive than everyone
previously thought they were, indicating that this setting could only
have had water for only a brief period of time," said Koeppel. "For some people, that kind of sucks the air out of the story because we often think
that having more water for more time means there's a greater chance of
life having been there at one point. But for us, it's actually really interesting because it brings up a whole set of new questions. What are
the conditions that could have allowed there to be water there for a brief amount of time? Could there have been glaciers that melted quickly with outbursts of huge floods? Could there have been a groundwater system that percolated up out of the ground for only a brief period of time only to
sink back down?" Koeppel started his college career in engineering and
physics but switched to studying the geological sciences while earning
his master's degree at The City College of New York. He came to NAU to
work with Edwards and immerse himself in the thriving planetary science community of Flagstaff.

"I got into planetary science because of my excitement for
exploring worlds beyond Earth. The universe is astoundingly big,
even Mars is just the tip of the iceberg," Koeppel said. "But
we've been studying Mars for a few decades now, and at this
point, we have a huge accumulation of data. We're beginning to
study it at levels that are comparable to ways we've been able
to study Earth, and it's a really exciting time for Mars science." ========================================================================== Story Source: Materials provided by Northern_Arizona_University. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Ari H.D. Koeppel, Christopher S. Edwards, Andrew M. Annex, Kevin W.

Lewis, Gabriel J. Carrillo. A fragile record of fleeting water
on Mars.

Geology, 2021; DOI: 10.1130/G49285.1 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/11/211130150450.htm

--- up 2 weeks, 5 days, 2 hours, 54 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)