A passion for the natural world drives many of our adventures. And when we’re not actually outside, we love delving into the discoveries about the places where we live and travel. Here are some of the best natural history links we’ve found this week.
New images of the heart of the Milky Way: This week, we saw a new image of the heart of our galaxy. Unlike any previous image of outer space, it looks like a piece of modern art. The MeerKAT radio telescope in South Africa combines 200 hours of observation and 20 separate images over three years to produce this accidental oeuvre.
The satellite captured radio waves from different astronomical events. The bottom right-hand side shows the remnants of a supernova, while the bright orange eye in the center is a supermassive black hole. Stronger radio signals register in red and orange. Fainter zones are gray; darker shades indicate stronger emissions.
Accelerated electrons gyrating in a magnetic field create the vertical filaments, but there is no known engine to accelerate the particles. “They were a puzzle. They’re still a puzzle,” says astrophysicist Farhad Yusef-Zade.
Tiger sharks’ quest for cooler oceans may land them in hot water
Tiger sharks are migrating further north: Waters off the northeastern U.S. are warming rapidly. Since the 1980s, the temperature has increased by 1.5˚C. This has rewired the marine ecosystems in the area. Some species have moved into new areas, others have disappeared altogether.
The warmer water has even affected the area’s apex predator, the tiger shark. Tiger sharks are migrating 430km further north than they did 40 years ago. This may have an indirect effect on the shark’s population. Though numbers are currently stable, the new pattern moves them out of marine protected areas. “Tiger sharks reproduce and grow slowly, which makes them more vulnerable to threats like fishing,” explains researcher Neil Hammerschlag.
Tiger Sharks are moving north. Photo: Shutterstock
Switzerland covered in 3,000 tonnes of nanoplastics each year: Across the Alps and lowlands, 3,000 tonnes of nanoplastics cover Switzerland each year. Researchers took snow samples from the top of one peak, Hoher Sonnblick, every day. They analyzed the contamination levels and used weather data to track the origin of the tiny plastic particles. One-third came from urban areas within 200km. Some came from the oceans, where the plastic drifted great distances in the air because of spray from waves — amazing that this reached such a landlocked country. Nanoplastics can pose a serious health threat. Particles smaller than 10 microns can enter our lungs and eventually our bloodstream.
The Antarctic Paradox
Unpredictable sea ice behavior around Antarctica explained: Sea ice loss in the Arctic follows predictable patterns and models, but the ice around Antarctica is more capricious. Antarctic sea ice remains fairly constant, despite warming temperatures. This is known as the Antarctic Paradox, and scientists have been at a loss to explain it.
A new study suggests that ocean eddies may delay sea-ice loss. Previous models suggested that the eddies drove more heat toward Antarctica than they actually do. In fact, the eddies neither help nor hurt. This means that the amount of heat transported north is higher than previously thought, and the Southern Ocean is not warming as quickly as expected.
The Greenland Ice Sheet. Photo: Shutterstock
Greenland ice sheet lost enough water in 20 years to cover U.S.: Since 2002, the Greenland ice sheet has lost 4,700 billion tonnes of ice from global warming. This is enough water to submerge the entire United States. Overall, it has caused a 1.2cm sea-level rise. The climate is warming faster in the Arctic than anywhere else on the planet. Satellite images show the most affected areas are the arctic coasts, especially west Greenland. “The ice is thinning, the glacier fronts are retreating in fiords and on land, and there is a greater degree of melting from the surface of the ice,” said the Danish study.
The International Space Station shows its age
The end of the International Space Station: The 30-year-old International Space station is starting to show its age. Astronauts regularly report technical problems, cracks, and leaks. NASA will keep the ISS running until 2030, but plans to repurpose it for private and commercial missions. They are predicting that the station will cease being useful in January 2031. This is when it will start to fall back towards Earth. Its size means it will not burn up in the atmosphere. NASA will need to control its fall using propulsion built into the station, and by other vehicles. They will guide it to touch down in the South Pacific Ocean, the furthest point on Earth from land.
