Max Winkler – Geobites

May 16, 2023May 16, 2023

Biomolecules on icy worlds

Featuring image: Artists impression of Hayabusa2 approaching Ryugu. Image credit: NASA/JPL, Public Domain (CC0)

Paper: Uracil in the carbonaceous asteroid (162173) Ryugu

Authors: Y. Oba, T. Koga, Y. Takano, N. O. Ogawa, N. Ohkouchi, K. Sasaki, H. Sato, D. P. Glavin, J. P. Dworkin, H. Naraoka, S. Tachibana, H. Yurimoto, T. Nakamura, T. Noguchi, R. Okazaki, H. Yabuta, K. Sakamoto, T. Yada, M. Nishimura, A. Nakato, A. Miyazaki, K. Yogata, M. Abe, T. Okada, T. Usui, M. Yoshikawa, T. Saiki, S. Tanaka, F. Terui, S. Nakazawa, S. Watanabe, Y. Tsuda and Hayabusa2-initial-analysis SOM team

Bringing a space probe to an asteroid is hard. Bringing back a piece of that asteroid to Earth is even harder. Nevertheless, Hayabusa2 successfully brought back samples from the asteroid Ryugu and gives us valuable insight on the abundance of biomolecules in our solar system.

What the Japanese space agency JAXA accomplished is extraordinary. After the successful sample return mission of Hayabusa from asteroid 25143 Itokawa in 2010, the successor mission again was able to bring us back precious, pristine asteroid material, including gas samples. In contrast to Itokawa, the new target Ryugu represents a much more pristine asteroid, chemically connected to a class of meteorites called carbonaceous chondrites. Researchers already detected the very building blocks of life, like amino acids and nucleobases, in these meteorites. The careful analysis of the Hayabusa2 samples revealed that one of the nucleobases, uracil, is also present in Ryugu.

February 24, 2023March 3, 2023

Soot in the water – Understanding oceans’ carbon cycle

Featuring image: soot produced by incomplete burning by fossil fuels. Picture: Pxhere, Public Domain (C0)

Paper: Hydrothermal-derived black carbon as a source of recalcitrant dissolved organic carbon in the ocean

Authors: Y. Yamashita, Y. Mori, H. Ogawa

Earth’s oceans not only harbour a multitude of organisms, they are also a major carbon sink, compensating the increased production of carbon by humans and thus slowing down climate change. But could hydrothermal vents be another source of carbon in the oceans themselves?

A lot of the carbon that is produced on land by organisms and industry is transported into the oceans by rivers and wind. Black carbon (or soot), which is for example produced by incomplete burning of fossil fuels, can be stored in the oceans and remain inaccessible for long periods of time (several thousand years). But is all the stored black carbon coming from land sources? Although scientists already had some hints that not all dissolved black carbon (DBC) in the oceans comes from the land, a reliable evidence for a DBC source within the oceans remained elusive. The research from a group from Japan was able to shine new light on this question by looking at hydrothermal vents in the Pacific Ocean.

January 26, 2023January 26, 2023

How plants left a mark on history

Featuring image: Plants slowly eroding limestone. Picture from Jon Sullivan, public domain (C0).

Paper: Composition of continental crust altered by the emergence of land plants

Authors: C. J. Spencer, N. S. Davies, T. M. Gernon, X. Wang, W. J. McMahon, T. R. I. Morrell, T. Hincks, P. K. Pufahl, A. Brasier, M. Seraine and G.-M. Lu

In the winter of 1990, the first Voyager spacecraft looked over its shoulder and snapped an iconic photo of Earth as a ‘pale blue dot’ in the vast cosmos. But when you look at it from Space, there is another very important colour: green. Plants cover a major portion of the landmasses. Besides bringing their bright chlorophyll colour to the continents, new research by Spencer and co-authors finds that plants have also slowly changed the composition of the Earth’s crust over hundreds of millions of years.

In a recent study, Spencer and co-workers were able to connect the development of land plants to changes in the geochemical composition of crustal rocks through the effects that plants had on landscapes, weathering, and sediments. Land plants arose during the early Ordovician period, about 440 million years ago, and today they cover approximately 84% of Earth’s landmasses. After they spread all over the continents, plants started to heavily influence the sedimentary cycles between continents and oceans.

October 25, 2022October 25, 2022

The seeds of continental crust

Featuring image: Lava lake in Hawaii Volcanoes National Park, May 1954. Photo by J.P. Eaton, Public Domain (C0).

Paper: Did transit through the galactic spiral arms seed crust production on the early Earth?

Authors: C.L. Kirkland, P.J. Sutton, T. Erickson, T.E. Johnson, M.I.H. Hartnady, H. Smithies, M. Prause

Plate tectonics reshape the face of Earth over long periods of time, but how the first continental crust evolved is still unclear. Now, a new investigation of very old rocks showed that Earth structure might have been influenced by the galactic dance of our solar system through the Milky Way.

The dating of old continental crust from the Precambrian (2.8 – 3.6 billion year old rocks) indicates that the formation of continental crust happened in cycles. Scientists discovered these cycles, which indicate that the crust didn’t form continuously, decades ago by dating minerals contained in continental crust all over the globe. Now, new research suggests that these cycles correspond to the periods where Earth passed through the spiral arms of our galaxy, the Milky Way.

September 14, 2022September 14, 2022

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.

August 31, 2022August 31, 2022

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.

July 26, 2022July 26, 2022

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.

June 18, 2022November 23, 2022

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.

April 26, 2022April 26, 2022

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.

March 14, 2022March 14, 2022

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.