Looking for life on Mars: what can the valleys that once flowed into Jezero crater tell us about the best rocks to sample?

Featured image: Artist depiction of the Mars 2020 Perseverance Rover on Mars. Public domain (NASA/JPL-Caltech).

Paper: Fluvial Regimes, Morphometry, and Age of Jezero Crater Paleolake Inlet Valleys and Their Exobiological Significance for the 2020 Rover Mission Landing Site.

Authors: Nicolas Mangold, Gilles Dromart, Veronique Ansan, Francesco Salese, Maarten G. Kleinhans, Marion Masse, Cathy Quantin-Nataf, and Kathryn M. Stack.

On Mars, we see a very different landscape to that on Earth. Although now an arid planet, great scars visible from space – such as the colossal Valles Marineris, which dwarfs Earth’s Grand Canyon – hint at a once watery world. But scientists still aren’t sure whether water on Mars might once have hosted life. On the 30th of July, NASA will launch the Mars 2020 mission, which will gather clues about the planet’s past and seek signs of ancient life on Mars. An essential part of such a space mission is extensive planning, so that scientists can target the most important rocks for study and sampling when the rover gets to Mars. A recent study by Nicolas Mangold and colleagues did just that by looking closely at the landing site for this next Mars mission, known as Jezero crater.

Continue reading “Looking for life on Mars: what can the valleys that once flowed into Jezero crater tell us about the best rocks to sample?”

Small Sediment’s Big Impact on Flash Floods

Featured image by Hans from Pixabay.

Paper: Modeling the Effects of Sediment Concentration on the Propagation of Flash Floods in an Andean Watershed

Authors: María Teresa Contreras and Cristían Escauriaza

Climate change has altered weather patterns around the world and has even led to increased heavy rainfall in some regions.  This, combined with El Niño – a weather pattern produced by unusual winds that can cause some regions to experience heavier than normal rainfall – has led to high numbers of catastrophic flash floods in populated areas near the Andes mountains.  To add insult to injury, climate models predict increases in heavy rainfall events in the future, further worsening the chance for flash floods. New research from scientists working in Chile and the United States aims to model the impact of these floods on communities by simulating realistic flash flood conditions with different amounts of sediment, a potentially dangerous component of flash floods in mountainous regions.

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Ancient microbes engineered sedimentary deposits

Cambrian Stromatolites from New York State

Featured image: Cambrian stromatolites from New York State. Image attribution: James St. John / CC BY 2.0; Wikimedia Commons

Paper: Evidence for microbes in early Neoproterozoic stromatolites

Authors: Zhongwu Lan, Shujing Zhang, Maurice Tucker, Zhensheng Li, Zhuoya Zhao

Stromatolites are ancient, layered deposits of sediments that are characterized by thin, alternating light and dark bands. While microbial fossils have been found in many stromatolites, the biological origin of these structures has been debated. Continue reading “Ancient microbes engineered sedimentary deposits”

What Caused the Flood that (Possibly) Gave Rise to an Empire?

Featured image: The Yellow River Breaches its Course by Ma Yuan, Public Domain

Paper: Uranium isotopic constraints on the nature of the prehistoric flood at the Lajia site, China
Authors: Le Li, Jun Chen, David William Hedding, Yuanhe Fu, Maolin Ye, Gaojun Li

A small sand deposit might hold the key to dating the rise of China’s first dynasty. Continue reading “What Caused the Flood that (Possibly) Gave Rise to an Empire?”