Welcome to GeoUnion, the graduate student body of the Department of Earth, Environmental and Planetary Sciences. GeoUnion strives to supplement the overall graduate student experience at Rice and DEEPS. GeoUnion represents DEEPS in the overall Rice grad student community, acts as a liaison between students and faculty and organizes a number of intra- and inter-departmental events throughout the academic year.
– FEBRUARY 19, 2021
Terror, be gone! This happy landing was pure delight.
It remains to be seen how well the Perseverance rover and its helicopter, Ingenuity, perform as they traverse the surface of Mars, but for the moment NASA and Rice geologist Kirsten Siebach are getting a moment to celebrate with the spacecraft’s long-awaited successful landing on Feb. 18.
Siebach and her colleagues gave an hourlong talk and Q&A session via Zoom before the notorious “seven minutes of terror,” during which the spacecraft would be on its own to execute the complex landing sequence to Jezero Crater.
The action shifted to Rice’s Visualization Laboratory, where Siebach shared her reaction to live reports from mission control at the Jet Propulsion Laboratory at Caltech with Rice video producer Brandon Martin.
The Perseverance work for Siebach is just beginning as she assumes her duties as a mission specialist tasked with helping operate the rover and scout for samples that will ultimately be brought back to Earth. These, she said, will lead to years of study to determine what Mars is made of, and whether life in any form ever existed there.
In the meantime, she is still studying data from the last rover to land, Curiosity, in 2012. She recently issued a paper that concluded the region’s climate was once like Iceland, and just this week was part of a paper that revealed the chemical contents of aqueous processes on a mixture of amorphous materials found at Gale Crater. That evidence suggests water persisted at Gale Crater for about 1 billion years.
Thursday February thee 18th was a big day. From her office in the Keith Wiess Geological Laboratories, EEPS planetary scientist Kirsten Siebach led a Mars 2020 mission virtual landing party. More than 120 participants were treated to a first-hand account of the upcoming landing from one of only 13 scientists chosen to operate the rover and help select samples.
Siebach answered numerous questions about the Mars 2020 mission, the Perseverance Rover and its analytical instrument payload, and the sample collection activities that she will be helping to direct. You can watch both the Q&A and entire landing party zoom meeting HERE.
At about 5 minutes from Mars 2020 atmospheric entry, Kirsten moved to the EEPS Chevron Visualization Laboratory where she watched the final countdown—known as Entry Descent and Landing or EDL, with Rice undergraduate Madison Morris. Morris is working with Siebach on research related to the upcoming rover activities.
The final 7-10 minutes, known as the ‘seven minutes of terror’, is the period during which the spacecraft must operate on its own, with no eyes to see and a 14 minute data delay back to Earth.
During those seven minutes, the spacecraft enters Mars atmosphere at almost 12,000 miles per hour (19,000 kmh). Facing towards the planet, a heat shield is the only protection the rover has as it descends down to an altitude of about 1 mile (1.5 km). The descent module then fires its engines to slow the spacecraft while JPL’s new terrain relative navigation system (TRN) identifies a place to land. The TRN scans the surface and compares it with maps of a landing ellipse that are already loaded into its database. A signal from the TRN triggers the deployment of a 70-foot (21-meter) diameter parachute that slows the craft further, bringing its descent down to a few meters per second. Finally, the hovering-landing sky crane system lowers the rover the rest of the way to the ground.
Siebach sits in silence, listening to the engineers mark each step in the process. At the final minute she stands, looking intently at the screen. As the flight engineers signal a successful deployment of the sky crane, cheers erupt on screen and in the Viz Lab. Perseverance has landed!!!
And the first picture from Jezero crater arrives.
Perseverance is proceeded by four other rovers, Sojourner in 1997, Spirt and Opportunity in 2004, and Curiosity in 2012. Perseverance is the largest, most advanced rover NASA has sent to another world. It traveled 293 million miles (472 million km) – over 203 days – to get to Mars. It will look directly for signs of past life on Mars, test ISRU tools, and collect samples from one of Mars oldest regions—what scientists believe is a river delta. The rocks in this region could tell us about Mars earliest wet history of the Red Planet and thus is a good target for signatures of past life.
– FEBRUARY 12, 2021
Early-career honor goes to fourth Rice U. geochemist in 12 years
Rice University’s Mark Torres has won the Geochemical Society’s top honor for early-career scientists, the F.W. Clarke Award, becoming the fourth Rice faculty member to win the award since 2009.
Torres, an assistant professor in the Department of Earth, Environmental and Planetary Sciences, joined Rice in 2017. He will receive the 2021 Clarke Award at the society’s annual meeting in July in recognition of “his work on the geochemistry of the Earth’s surface focused on interactions between the hydrosphere, cryosphere, atmosphere, biosphere and the crust.”
Torres said the impact of the honor sank in when he looked at the list of previous winners and recognized names from “papers I read as a student that really impressed me and sort of guided or shaped my thinking. To be on that same list is amazing. And then, similarly, to also have this legacy of so many other Rice faculty in my department winning. It’s fun to join the club.”
The Clarke Award honors outstanding contributions to geochemistry or cosmochemistry and is awarded to a single individual each year. Torres joins Rice Clarke Award winners Cin-Ty Lee (2009), Rajdeep Dasgupta (2011) and Laurence Yeung (2016).
Torres’ lab focuses on interactions between rock and water near Earth’s surface, the transport and burial of organic carbon and how the oxidation of sulfide minerals affects atmospheric carbon dioxide levels.
“At Earth’s surface, materials like water and sediment tend to move and chemically react at the same time,” Torres said. “If you think about rivers, for example, there’s chemistry that happens as the river flows. Groundwater flows into the rivers, and there’s chemistry that happens during that process too.
“It turns out, how fast something moves dictates how much chemistry you can do,” he said. “Things happen at a certain rate, and how quickly something goes from point A to point B determines how much it can react. At the same time, the chemistry changes how fast it moves. Do sediment grains get smaller? Do they get bigger? Right? Do we dissolve things? Or do we precipitate new things? So, transport and reaction end up feeding back on each other, resulting in complex patterns. And so a lot of my research is sort of thinking about those kinds of problems.”
Torres grew up in Southern California and was fascinated by dinosaurs as a child. His interest in paleontology and geology continued in high school, when he spent summers hunting fossils and afternoons cleaning dinosaur bones at the Alf Museum of Paleontology on his high school campus. But he also had a growing interest in environmental issues, especially climate change, and he enrolled as an environmental studies major at Pitzer College in Claremont, California.
“For some reason, I thought that despite all my interest in the Earth sciences, that I would do that,” he said. “I got about a semester in, and I was like, ‘Oh, wait. No. Obviously, I want to be a geologist.’ And so, it was like, a really quick switch.”
Torres cited his parents and Alf Museum director Don Lofgren as important early influences, and his Ph.D. advisor at the University of Southern California, Josh West, as a critical late influence. But Torres’ passion for geochemistry emerged in the laboratories of undergraduate mentors Robert Gaines and Jade Star Lackey, both of Pomona College. Torres said Gaines’ research on the geochemistry of Burgess Shale fossils was particularly pivotal.
“It’s a unique type of fossil deposit, and he studies it from the perspective of geochemistry,” Torres said. “Like, what about this place at this time — the seawater — allowed us to have access to these fossils?
“And that little twist on paleontology took,” he said. “In my mind, it was like, ‘Oh. The tools to answer a lot of the questions that interest me — like, what was the Earth like in the past? How will it change in the future? What sets Earth’s climate? — are kind of rooted in chemistry.’ Those questions are fundamentally linked to paleontology, what I thought was originally my passion. But being around (Gaines and Lackey), at that time, really showed me, ‘Oh, no, no. Geochemistry is it.’”
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