January 8, 2024: A last-in-a-generation eclipse is happening this spring, rivers in Alaska are turning orange and Brazil's rampant use of agricultural pesticides. —Andrea Gawrylewski, Chief Newsletter Editor | | | On April 8 the moon will pass in front of the sun, turning day to night for up to four minutes for onlookers in North America in the path of the moon's shadow. The next total solar eclipse across the continent won't be until 2044. The brief block of the sun's overwhelming brilliance offers scientists the rare chance to conduct novel kinds of experiments. Dive into some of the studies in this story by Jonathan O'Callaghan.
The sounds: Hundreds of small, microphone-equipped electronic devices dispersed to volunteers around the country will listen for shifts in animal noises while the moon creates a false night.
The corona: The outermost region of the sun's atmosphere can reach millions of degrees. During the eclipse, infrared cameras mounted to NASA aircraft will take images of the corona, hopefully capturing giant magnetic plasma eruptions originating on the surface. Radio waves: Wherever the moon's shadow falls, it creates a "hole" in the ionosphere—the ionized region of Earth's atmosphere 80 to 1,000 km above the planet's surface. Physicists and engineers will be monitoring how this drop in ionization affects the transmission of radio waves.
What the experts say: "This eclipse will be a once-in-a-generation chance for many scientists and members of the public to witness the phenomenon first-hand without traveling internationally," says Lee Billings, senior editor for space and physics. | | | In the last few years, scientists have recorded rivers and streams in pristine regions of Alaska that are as acidic as vinegar and have levels of electrical conductivity, an indicator of dissolved metals or minerals, similar to industrial wastewater. Plus, the waterways are turning orange. Scientists agree that climate change is behind the changes, but aren't yet sure precisely how. The first possible explanation is that thawing permafrost allows bacteria to reduce iron, which is soluble in water. Once in the water, that reduced iron can be oxidized, turning bright orange. The second possibility is that the permafrost thaw lets iron leach out of the bedrock for the first time in thousands of years. The metal gets oxidized in streams and rivers, turning the water orange.
Why this matters: Iron in the water suffocates the invertebrates that fish feed on. And iron and other metals hinder fish respiration. Salmon, in particular, are keystone species in the rivers of Alaska, and their health directly impacts many of the other living organisms in the ecosystem they occupy. Native Alaskans also depend on the rivers for fish and drinking water.
What the experts say: "It's fascinating from a scientific point of view, but from an emotional point of view, it's sad," says U.S.G.S biologist Mike Carey of the changes he's witnessing. "The alarming thing is how far our human reach is, in a big way." | | | Tukpahlearik Creek in northwestern Alaska's Brooks Range runs bright orange where permafrost is thawing. Credit: Taylor Roades | | | • Buying out and razing homes damaged by hurricanes boosts business development, jobs and property values in nearby neighborhoods, research finds. | 3 min read | | | • This scholar of literature discovered a likely pen name for author Louisa May Alcott. | 6 min read | | | • Neurons are highly complex structures that are similar across animal lineages. But recent biological studies suggest that this cell type could have evolved more than once. | 6 min read | | | • A disregard of scientific research has bolstered the rampant approval in Brazil of hundreds of pesticides for agriculture in the last few years. Some estimates attribute 11,000 deaths annually to pesticides in developing countries. "The world's food security cannot do without the health security of consumers and concern for the environment," writes Heslley Machado Silva, a professor and researcher at the University Center of Formiga/MG (UNIFOR/MG) and the State University of Minas Gerais (UEMG) in Brazil. | 5 min read | | | The researchers in Alaska who spoke to our reporter said that melting permafrost around the world is likely having an array of geochemical impacts. Last month I wrote about a new permafrost atlas that details the extent of this frozen land and how it's changing. It's a fascinating compendium worth checking out. | Thank you for reading Today in Science. Reach out any time with feedback or suggestions: newsletters@sciam.com. See you tomorrow! | —Andrea Gawrylewski, Chief Newsletter Editor | | Subscribe to this and all of our newsletters . | | | | Scientific American
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