Chicxulub’s small sibling

Featuring image: 66 million years ago, a giant meteorite impact ended the age of the dinosaurs. Artist impression of the impact. Painting by Donald E. Davis, Public Domain (C0)

Paper: The Nadir Crater offshore West Africa: A candidate Cretaceous-Paleogene impact structure

Authors: U. Nicholson, V. J. Bray, S. P. S. Gulick, B. Aduomahor

The appearance of a flaming, 10 km wide meteorite over the Gulf of Mexico must have been striking, literally. But could the meteorite, which killed the dinosaurs, have had a small sibling or even a whole family of smaller space rocks hurtling towards Earth?

The massive meteorite impact at Chicxulub in the Gulf of Mexico ended the era of the dinosaurs 66 million years ago. Now, only a few thousand km apart from it, researchers might have found another, smaller crater of a similar age. And it might show that the Chicxulub meteorite was not alone but part of a cluster of meteorites, bombarding the Earth at the end of the Cretaceous period.

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The rise of Sponges

Featuring image: Venus flower basket glass sponges (Euplectella aspergillum) in the Gulf of Mexico. NOAA Okeanos Explorer Program – Gulf of Mexico 2012 Expedition, CC-BY-2.0

Paper: Palaeoecological Implications of Lower-Middle Triassic Stromatolites and Microbe-Metazoan Build-Ups in the Germanic Basin: Insights into the Aftermath of the Permian–Triassic Crisis

Authors: Y. Pei, H. Hagdorn, T. Voigt, J.-P. Duda, J. Reitner

The Permian-Triassic crisis was the greatest mass extinction in Earth’s history. But an unlikely animal might have benefited from this cataclysm: the sponge.

Microbial mats like stromatolites represent the lithified remains of different slimy accumulations of microorganisms. While there are many different types, Pei and co-workers investigated a special type of microbial mats with a very different internal structure, called microbial-metazoan build-up, mainly consisting of sponges. By comparing these fossil structures to common stromatolites from the Permian-Triassic boundary, the researcher team could show that sponges profited from the mass extinction with the aid of bacteria.

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Dreaming of a green Moon – farming lunar fields

Featuring image: Cress can grow nearly everywhere, but can it also survive on the Moon? Bastet78, Wikimedia Commons, Creative Commons (CC BY-SA 4.0).

Paper: Plants grown in Apollo lunar regolith present stress-associated transcriptomes that inform prospects for lunar exploration

Authors: A.-L. Paul, S. M. Elardo and R. Ferl

Plants surround us everywhere and dominate our planet. We feed from them, we build our homes from them and we need them as a source for oxygen. We couldn’t imagine a world without them. But can we take them with us, when we visit other worlds?

In space science, plants have already played an important role. They are often used as model organisms for experiments and in future space missions they might even be used as important additions to the astronauts’ food and life supply. Thus, they already made their way up to the International Space Station. Now for the first time, Paul and colleagues have tried to grow plants in original lunar soil, finding that we may be able to take our green companions with us to the Moon.

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Ice from fire – When volcanos let it snow

Featuring image: Erruption of the Raikoke Volcano on June 22, 2019. Volcanos can exhaust a large amount of gases and dust during eruptions. Is this enough to create an atmosphere on the Moon? NASA’s Earth Observatory, public domain (CC0).

Paper: Polar Ice Accumulation from Volcanically Induced Transient Atmospheres on the Moon

Authors: A. X. Wilcoski, P. O. Hayne and M. E. Landis

The Moon is a silent and dry, yet beautiful desert. Where it comes from and how much ice exits is still a mystery. It can be found in the darkness of its pole regions as ice. Surprisingly, the eruptions of volcanos might have helped the Moon to keep its water.

The gas that is set free during a volcano eruption contains different volatile molecules, including water. On small celestial objects without an atmosphere like the moon, most of the gases are released to space. A new study suggests that not all water vapour from such eruptions escaped from the Moon during its history. Instead, local and short-lived atmospheres might have formed during eruptions, allowing a part of the water vapour to cool down and deposit as snow and ice.

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How to connect methane in atmosphere to a planets geology and biology

Featuring image: Titan’s atmosphere is rich in organic molecules, but we still don’t know if there is life on Saturn’s icy moon. With JWST and the coming generation of telescopes, we will be able to observe the atmospheres of exoplanets. Is there a way to search for life on these distant worlds? NASA/JPL, public domain (CC0).

Paper: The case and context for atmospheric methane as an exoplanet biosignature

Authors: M. A. Thompson, J. Krissansen-Totton, N. Wogan, M. Telus and J. J. Fortney

Visiting and exploring exoplanets for extraterrestrial life still belong to the realm of science fiction. However, the coming generation of telescopes will enable us to look into the atmospheres of exoplanets and search for possible biosignatures, chemical compounds that could indicate the presence of life.

Searching for life on a planet is not a trivial task. Since the first Mars landing in 1976, scientists still search for recent or ancient traces of life. It becomes even more difficult on planets that we cannot directly visit. The next telescope generation will enable us to observe the atmosphere of distant planets remotely. Are there ways to find evidence of life in a planet’s atmosphere? A new study suggests that the freshly launched James Webb Space Telescope (JWST) could help us to search for life on other worlds.

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Looking into Ceres interior

Featuring image: Ceres is the largest body inside the main asteroid belt. Could this icy dwarf planet be still geological active? NASA/JPL-CalTech/UCLA/MPS/DLR/IDA, public domain (CC0).

Paper: Brine residues and organics in the Urvara basin on Ceres

A. Nathues, M. Hoffmann, N. Schmedemann, R. Sarkar, G. Thangjam, K. Mengel, J. Hernandez, H. Hiesinger, J. H. Pasckert

When you think about asteroids, you might picture an old, cold collection of rocks and dust. But the closer we look at them, the more complex these bodies turn out to be. Could some of them still be geologically active?

Ceres, a major body in the main asteroid belt, is covered by several big impact craters. A group of researchers led by Dr. Nathues from the Max Planck Institute for Solar System Research, used data from a former space mission to investigate the geology of one of the most prominent impact craters. Not only did they find the expected landscape of a post-impact region, but they also found signs of more recent geological processes and evidence for a global brine layer under the surface of Ceres.

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The first mass extinction

Featuring image: Life on during the Ordovician period looked very different then today. Animals like anomalocarididaes were very common, but many species vanished at the end of the Ordovician. A new study sheds light on the first mass extinction event. Model created by Espen Horn, photo: H. Zell, Creative Commons (CC BY-SA 3.0).

Paper: Geochemical Records Reveal Protracted and Differential Marine Redox Change Associated With Late Ordovician Climate and Mass Extinctions

Authors: N. P. Kozik, B. C. Gill, J. D. Owens, T. W. Lyons and S. A. Young

As mountains rise and continents fall apart, it not only changes the face of the Earth, but also drastically affects its inhabitants.

Earth’s biosphere was disrupted by several mass extinction events, often connected to great changes in large geologic cycles. These times of great disasters were also a chance for pioneers and led to great evolutionary leaps. A new study suggests that the oldest of the known major mass extinctions during the Ordovician was caused by a change in climate and the ocean’s circulation system.

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Do we need new types of geology to understand exoplanets?

Featuring image: White dwarf make perfect natural mass spectrometer, more powerful as any instrument on Earth. Can they help us to learn about exoplanets? NOIRLab/NSF/AURA/J. da Silva, Creative Common (CC BY 4.0)

Paper: Polluted white dwarfs reveal exotic mantle rock types on exoplanets in our solar neighborhood

Authors: K. D. Putirka and S. Xu

For a long time, geologist were only able to study rocks on the ground. We extended this knowledge to our neighbouring planets. Now finally, scientist have found a way to study rocks from planets far away, using the light of their host stars. And they look very strange.

Over the last 30 years, exoplanets have evolved from mere theory into a fantastic reality. Today we know that nearly all stars host at least one exoplanet and even exoplanets with an Earth-like mass are relatively common. Still, we know very little about the geology of these worlds. In a new study, Keith Putirka and Siyi Xu were able to observe and compare the mineralogy of exoplanets to that of the rocky planets in the solar system. Surprisingly, these exoplanets exhibit types of mineralogy unlike any we have known before.

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How did giant impacts influence our atmosphere?

Featuring image: Oxygen was not always present in Earth’s atmosphere, but stated to accumulate only around 3.5 billion years ago. Pixabay, Public Domain (CC0)

Paper: Delayed and variable late Archaean atmospheric oxidation due to high collision rates on Earth

Authors: S. Marchi, N. Drabon, T. Schulz, L. Schaefer, D. Nesvorny, W. F. Bottke, C. Koeberl and T. Lyons

Take a deep breath. Your lungs fill with air and vital oxygen. Not only you, but all higher life depends on oxygen. In the Archean aeon, which lasted from 4 to 2.5 billion years before present, Earth’s atmosphere contained no oxygen. How did oxygen accumulate in the atmosphere? A team of researchers discovered that the evolution of our atmosphere was strongly influenced by impacts of large meteorites when our planet was still young.

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Call of Cthulhu — Can we uncover the secret of Pluto’s red spots?

Featuring image: Pluto is an icy object in the outer solar system. Its surface it not only covered by ice, but also by an unidentified red material. The largest of these red areas is the Cthulhu region in the southern hemisphere. NASA/JHUAPL/SwRI, public domain (CC0)

Paper: Testing tholins as analogues of the dark reddish material covering Pluto’s Cthulhu region

Authors: M. Fayolle, E. Quirico, B. Schmitt, L. Jovanovic, T. Gautier, N. Carrasco, W. Grundy, V. Vuitton, O. Poch, S. Protopapa, L. Young, D. Cruikshank, C. Dalle Ore, T. Bertrand, A. Stern

Pluto is an icy object beyond Neptune. Its surface is not only covered by innocent pale ice, but also by mysterious dark-red fields. What lurks in these hellish regions and where do they come from?

Far behind Neptune’s orbit, the icy body Pluto orbits our Sun. Pluto got a lot of attention in 2006, when it lost its status as a planet. Since then, it remained as a trans neptunian objects (TNO) of major interest. In 2015, Pluto presented itself in high resolution pictures for the first time in history, when NASA’s space probe New Horizons explored the outer regions of our solar system. What the pictures showed, was not the expected icy desert, but multiple areas of deep red all over Pluto’s surface. The largest of them is located on the southern hemisphere. As a homage to the master of subtle horror, H. P. Lovecraft, the area is called Cthulhu region, because some of the most mysterious and powerful beings in Lovecraft’s world originate from Pluto (in Lovecraft’s stories called Yuggoth). Fayolle and co-workers tried to better understand the origin of these red materials by using laboratory experiments and numerical modelling in comparison with the data recorded by the New Horizons space probe.

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