Science

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com. Why does the Earth spin? Sara H., age 5, New Paltz, New York A globe was the first thing I ever bought with my own money. I was maybe 5 years old, and I was really excited to take it home. As I quickly discovered, you can spin it in the direction that the earth actually spins. There’s an imaginary line between the North Pole and the South Pole. We call it the rotation axis. For the Earth, the rotation axis points toward a bright star, Polaris, which is visible on clear nights in the Northern Hemisphere. Satellite images over one day show Earth rotating on its axis. NASA/EPIC, edit by Tdadamemd If you want to know which way to spin your globe, make the...

Rivers are awash with excess nutrients, chemicals, and other pollutants, including sewage. Globally, roughly 50% of wastewater is treated at facilities before being released into nearby bodies of water. But new research shows that even advanced treatment might not be enough to safeguard the health of freshwater ecosystems. Researchers released dilute, treated wastewater into an unpolluted stream in northern Spain and made a before and after comparison of energy flows through the ecosystem. “We found subtle yet fundamental shifts in ecosystem function.” “We found subtle yet fundamental shifts in ecosystem function after adding wastewater,” said Ioar de Guzman, a freshwater ecologist at the University of the Basque Country in Spain and lead author of the study. By manipulating a pristine ecosystem, she and her colleagues could isolate the effects of wastewater, which can be masked in streams that contain other types of...

Subglacial environments on Earth offer important analogs to Ocean World targets in our solar system. These unique microbial ecosystems remain understudied due to the challenges of access through thick glacial ice (tens to hundreds of meters). Additionally, sub-ice collections must be conducted in a clean manner to ensure sample integrity for downstream microbiological and geochemical analyses. Subglacial environments on Earth offer important analogs to Ocean World targets in our solar system. These unique microbial ecosystems remain understudied due to the challenges of access through thick glacial ice (tens to hundreds of meters). Additionally, sub-ice collections must be conducted in a clean manner to ensure sample integrity for downstream microbiological and geochemical analyses. We describe the field-based cleaning of a melt probe that was used to collect brine samples from within a glacier conduit at Blood Falls, Antarctica, for geomicrobiological s...

A reflection of the planet’s increasingly volatile climate and the enduring influence of industrial interests, North American grasslands find themselves at the epicenter of one of the most severe biodiversity crises on the planet. Formerly a vibrant mosaic of life — teeming with migratory birds, diverse fauna herds and formidable predators — the Great Plains and its dwindling wildlife serve as a reminder of the delicate balance essential to sustain ecosystems while also supporting the success of industries necessary for the regional economy and human coexistence. Data indicates that, in the past century, over 60% of native grasslands, totaling 360 million acres, have vanished. Adding to this, another 125 million acres are at risk in the foreseeable future as warming temperatures create opportunities for expanded agriculture in the Northern Great Plains, while woodland encroaches upon grasslands in the Southern Great Plains. But the implic...

Human trade and transport have led to the intentional and accidental introductions of non-native species outside of their natural range globally. These biological invasions can cause extinctions, cost trillions, and spread diseases. A study from the GEOMAR Helmholtz Centre for Ocean Research Kiel, now published in Global Ecology and Biogeography, has investigated how many of these non-native species already exist worldwide and which species groups are particularly prone to become non-native. “Everything that exists can be introduced somewhere at some point,” says Dr. Elizabeta Briski. The marine biologist is an expert in invasion ecology at GEOMAR Helmholtz Centre for Ocean Research in Kiel. Along with a large international team of renowned ecologists, she has conducted a study to investigate whether non-native species mirror Earth’s patterns of biodiversity and found that greater numbers of non-native species...