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Robin is the founder and owner of The Biogeologist.

Aurora

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Auroras are a natural light phenomenon related to charged particles of solar winds that impact the Earth’s atmosphere at high altitude. Auroras are formed by ionization of atmospheric particles when solar winds result in significant disturbances of the magnetosphere. Subsequently, the energy of these particles is lost to the atmosphere, which emits light in different colors and intensities. Auroras may occur in several forms, but are known best for their green and red bands that illuminate the sky. They can be observed at high latitudes in the Arctic, where they are called Aurora Borealis or the Northern Lights, as well as in the Antarctic, where they are called Aurora Australis or Southern Lights.

Information source: Encyclopaedia Brittannica, Wikipedia

Image: Aurora Borealis as seen from Bear Lake, Alaska, USA. Credit: US Air Force/Joshua Strang.

Fossil pigments reveal that dinosaurs may have laid colored eggs

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Scientists at the University of Bonn have found pigments in fossilized eggs of dinosaurs, which indicates that dinosaurs may have laid colored eggs similar to modern birds. The scientists performed organic geochemical analyses on well preserved, 66 million year old fossil remains of eggshells belonging to the oviraptor Heyuannia huangi and discovered the presence of the pigments protoporphyrin and biliverdin. These pigments are known to be responsible for the blue and green colors in present-day robin and emu eggs, respectively, which suggests that the studied oviraptor eggs may have had blue-green colors as well. It is believed that these oviraptor eggs were laid in partially open ground nests and therefore, their blue-green coloring may have provided a means of camouflage against predators. This study is the first to reconstruct the color of dinosaur eggs and provides a link between the reproductive biology of dinosaurs and the evolutionary traits inherited by modern birds.

Journal reference: Wiemann, J., Yang, T. R., Sander, P. N., Schneider, M., Engeser, M., Kath-Schorr, S., … & Sander, P. M. (2015). The blue-green eggs of dinosaurs: How fossil metabolites provide insights into the evolution of bird reproduction (No. e1323). PeerJ PrePrints.

Image: Reconstruction of Tyrannosaurus rex in Palais de la Découverte, Paris, France. Source: David Monniaux, Wikimedia Commons.

The Twelve Apostles, Victoria, Australia

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The Twelve Apostles is a group of rock structures along the Great Ocean Road in Victoria, Australia. These limestone pillars were formed by wave erosion of caves and arches along the mainland cliffs. Eight pillars of the Twelve Apostles still remain, but there were only nine pillars in total.

Information source: Twelve Apostles Marine National Park Service

Image: The Twelve Apostles along the Great Ocean Road in Victoria, Australia. Source: Mike Lehmann, Wikimedia Commons.

Permian-Triassic mass extinction was caused by ocean acidification

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New findings of scientists from several universities published in Science show that the Permian-Triassic mass extinction (~ 252 million years ago), the greatest extinction event of all time, was caused by ocean acidification. The researchers studied boron isotopes from marine sediments in order to reconstruct seawater pH and subsequently combined these data with quantitative modeling techniques to develop a scenario for the mass extinction. Their results show that seawater pH remained relatively stable during the first phase of the extinction, but rapidly shifted to more acidic values during the second phase, which lasted ~ 10 thousand years. This acidification of the oceans had dramatic consequences for life on Earth and is thought to be associated with the release of massive amounts of carbon, related to the volcanism of the Siberian Traps. Up to 96 % of living marine species became extinct during the Permian-Triassic mass extinction and now, it has been shown for the first time that ocean acidification was the responsible mechanism.

Journal reference: Clarkson, M. O., Kasemann, S. A., Wood, R. A., Lenton, T. M., Daines, S. J., Richoz, S., … & Tipper, E. T. (2015). Ocean acidification and the Permo-Triassic mass extinction. Science, 348(6231), 229-232.

Image: Eruption of the Tavurvur volcano on February 13, 2009 near Rabaul, New Britain, Papua New Guinea. Source: Taro Taylor, Wikimedia Commons.

Mars

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Mars is the second smallest planet in the Solar System and the fourth planet from the Sun. It has a mean radius of ~ 3390 km, a mean distance to the Sun of ~ 228 million km and an orbital period of ~ 687 Earth days. Mars is a terrestrial planet with a reddish color, which is related to dust and rocks at its surface that are enriched in iron oxides. The planet is surrounded by a thin atmosphere and is characterized by impact craters, volcanoes, valleys as well as polar ice. Mars is also known for Olympus Mons, the largest volcano in the Solar System, and Valles Marineris, one of the largest canyons in the Solar System.

Information source: NASA

Image: Mars and the Valles Marineris as seen from the Viking 1 Orbiter. Source: NASA/Jet Propulsion Laboratory-Caltech.

Quartz

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Quartz is a major silicate mineral that consists of a series of silicon-oxygen tetrahedra in which each oxygen atom is shared, resulting in the chemical formula SiO2. It is the second most abundant mineral in Earth’s continental crust and it is relatively hard (Slavic ancestors of the German word quarz translate to “hard” in English). Quartz is often colorless but there are many different varieties in different colors, including semi-precious gemstones such as amethyst, citrine and chalcedony.

Information source: Mindat.org

Image: Quartz crystals found in the USA. Credit: Parent Géry, Wikimedia Commons.

Mercury

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Mercury is the smallest of the eight planets in the Solar System, with a mean radius of ~ 2440 km, a mean distance to the Sun of ~ 58 million km and an orbital period of ~ 88 Earth days. Mercury is a terrestrial planet with a surface characterized by impact craters and basaltic lava plains, similar to Earth’s Moon. Because it is the closest planet to the Sun and has almost no atmosphere, Mercury experiences the largest variations in surface temperatures of all planets in the Solar System.

Information source: NASA

Image: Mercury as seen from MESSENGER. Source: NASA/John Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.

Diamond

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Diamond is a gemstone that consists entirely of carbon (C). It is typically colorless and is the hardest natural mineral on Earth because of its very dense crystal structure (the Greek word adamas translates to ‘unbreakable’ in English). It is formed at high temperatures and pressures in the mantle and as a result it is metastable at Earth’s surface. Diamond is a precious stone commonly used in jewelry, together with sapphire, ruby and emerald.

Information source: Mindat.org

Image: White diamond crystal found in South Africa. Source: Parent Géry, Wikimedia Commons.

Emerald

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Emerald is a gemstone variety of the mineral beryl (Be3Al2(SiO3)6). It generally has a green color (the Greek word smaragdos translates to ‘green gem’ in English), which is related to the presences of trace amounts of chromium or vanadium in the mineral structure. Emerald is a precious stone commonly used in jewelry, together with sapphire, ruby and diamond.

Information source: Mindat.org

Image: Emerald crystals found in Colombia. Source: Parent Géry, Wikimedia Commons.

Ruby

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Ruby is a gemstone variety of the aluminum oxide mineral corundum (Al2O3). The red color from which its name is derived (the Latin word ruber translates to ‘red’ in English) is related to the presence of trace amounts of chromium in the mineral structure. Ruby is a precious stone commonly used in jewelry, together with sapphire, emerald and diamond.

Information source: Mindat.org

Image: Ruby crystals found in Vietnam. Source: Parent Géry, Wikimedia Commons.

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