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Astronomers discover most-distant Milky Way-like galaxy ever observed

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Aug. 12 (UPI) — Astronomers have discovered a Milky Way lookalike 12 billion light-years from Earth — the most distant Milky Way-like galaxy ever observed — according to a study published Wednesday in the journal Nature.

When scientists study light from so far away, they’re seeing something that is 12 billion years old, revealing the universe as it was just 1.4 billion years after the Big Bang.

Finding such a stable, intact galaxy was a surprise, astronomers said.

“Galaxies in the early universe are expected to be the site of powerful phenomena like supernova explosions, which release a lot of energy into the system,” study co-author Simona Vegetti told UPI.

While most theories of cosmic evolution depict the early universe as a place of turbulence and chaos, the gas found in the newly discovered galaxy — called SPT0418-47 — appears quite uniform.

“It is quietly rotating around the center of the galaxy,” said Vegetti, a researcher at the Max Planck Institute for Astrophysics in Germany. “It is very hard to explain this behavior within the context of the latest state-of-the-art numerical simulations of galaxies.”

The Atacama Large Millimeter/submillimeter Array, or ALMA — located in Chile, it is the largest telescope in the world — was able to image the distant galaxy and its smoothly flowing gas thanks to a phenomenon known as gravitational lensing.

When the gravity of a closer galaxy bends the light of a more distant galaxy, a magnifying lens-like effect enhances the faraway light. The phenomenon often is used to study galaxies that otherwise would be too far away to see.

Because the lensing effect both magnified and distorted the light of SPT0418-47, researchers had to use computer models to realistically depict the galaxy and the movement of its gas. The analysis revealed the newly found galaxy to be similar to the Milky Way.

Appearing circular with a central bulge is where the two galaxies’ similarities end, however, as the new galaxy is smaller and doesn’t have spiral arms, Vegetti said.

“We say that this galaxy is Milky Way-like essentially because it has a regularly rotating disc. Thus, it looks like a so-called ‘disc galaxy’ in the nearby universe,” study co-author Filippo Fraternali told UPI.

Though smaller, the universe looks to be quite mature. Most models of early galaxy evolution suggest it should take longer for galaxies to form stable flows and central bulges.

“A possible interpretation of our results is that both gas discs and bulges form much more rapidly than was thought previously,” said Fraternali, a researcher with the Kapteyn Astronomical Institute at the University of Groningen in the Netherlands.

Researchers now are trying to determine how common galaxies like SPT0418-47 are in the distant, or early, universe.

“Then, we are looking forward to the next generation of telescopes currently being built,” Vegetti said. “These new facilities will bring this type of analysis to the next level, allowing us to observe even younger galaxies with an even greater level of detail.”



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Florida Current study confirms decline in strength of Gulf Stream

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Aug. 7 (UPI) — New research suggests the strength of the Florida Current, which forms the beginning of the Gulf Stream, has weakened considerably over the last century.

The findings, published Friday in the journal Nature Climate Change, corroborate the predictions of several models that suggest the Gulf Stream has slowed over the last several decades.

The Florida Current is a thermal ocean current that flows from west to east around the tip of Florida, joining the Gulf Stream off Florida’s east coast.

Scientists have been tracking the strength of the Florida Current since the early 1980s — not long enough to identify multi-decadal or centennial trends.

To better understand the current’s historical changes, Christopher Piecuch, researcher at the Woods Hole Oceanographic Institution in Massachusetts, decided to study the relationship between coastal sea level and the strength of near-shore currents.

While researchers have only been measuring the Florida Current for a few decades, scientists have been recording sea level data since the early 1900s. Piecuch was able to use the data to predict historic changes in the strength of near-shore currents.

“In the ocean, almost everything is connected,” Christopher Piecuch, sole author of the new study, said in a news release. “We can use those connections to look at things in the past or far from shore, giving us a more complete view of the ocean and how it changes across space and time.”

The statistical analysis performed by Piecuch showed the Florida Current and Gulf Stream are the weakest they’ve been during the last 110 years.

The findings are in agreement with ocean current models that suggest climate change has caused a slowdown of the Atlantic Meridional Overturning Circulation, of which the Gulf Stream is a part.

Piecuch said he hopes his research will help other scientists use coastal current data to study changes in bigger currents like the Gulf Stream.

“If we can monitor something over the horizon by making measurements from shore, then that’s a win for science and potentially for society,” he said.



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SpaceX, ULA win large government launch contracts

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Astronauts make round trip to space station from U.S. soil

NASA astronaut Douglas Hurley (C) waves to onlookers as he boards a plane at Naval Air Station Pensacola to return him and NASA astronaut Robert Behnken home to Houston a few hours after the duo landed in their SpaceX Crew Dragon Endeavour spacecraft off the coast of Pensacola, Fla,, on August 2, 2020. Photo by Bill Ingalls/NASA | License Photo



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High levels of mercury, plastic toxins found in stranded whales, dolphins

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ORLANDO, Fla., Aug. 10 (UPI) — Dolphins and whales stranded on beaches in the southeastern United States had high levels of toxins, including mercury and chemicals found in plastic, according to a study published in the journal Frontiers in Marine Science.

Scientists who led the study said the data provides new, troubling information about the impact of pollution on marine mammals — knowledge that could help save vulnerable and declining species.

The findings also could be a warning for humans, because whales and dolphins eat seafood that people also eat, researchers said.

“We must do our part to reduce the amount of toxicants that enter into our marine environment, which have important health and environmental implications not just for marine life, but for humans,” lead author Annie Page-Karjian said.

“Dolphins eat a variety of fish and shrimp in these marine environments and so do humans,” said Page-Karjian, an assistant research professor of marine wildlife at Harbor Branch Oceanographic Institute in Fort Pierce, Fla.

Besides plastic chemicals, the study found toxins in the animals that included mercury, triclosan — an antibacterial agent used in consumer products like in soap and toothpaste — and atrazine, an herbicide.

The study, published last week, examined tissue from 83 dolphins and whales that became stranded from North Carolina to south Florida and died from 2012 to 2018. Eleven animal species were tested for 17 toxins.

The study is the first to report concentrations of toxicants in a white-beaked dolphin and in Gervais’ beaked whales, species for which the scientific literature remains sparse.

The researchers involved in the study are licensed to retrieve bodies of marine mammals nationally and internationally as part of a network to respond to the stranding of marine animals.

Such science collected from the dead animals is difficult to collect from live animals, and the stranded animals often are in stages of sickness or decay, said Justin Perrault, another study participant, who is director of research at Loggerhead Marinelife Center Juno Beach, Fla.

“Some of the mercury levels we found were the highest found anywhere in the world,” Perrault said. “It is eye-opening. To see the levels of some of these contaminants is alarming.”

Despite those high levels, the study was unable to determine if the toxins caused the animals to beach themselves, said James Sullivan, executive director at Harbor Branch.

“It’s really hard to judge, when an animal strands, if the toxins in the animal were related to why it stranded,” Sullivan said. “But these health problems do stack up. The animal is much more susceptible to succumbing to natural disease and environmental problems, just like humans are more likely to get ill from coronavirus if they have underlying conditions.”

Although the study focused on the Southeast, it has broader implications for marine mammal conservation, said John Calambokidis, senior research biologist with Olympia, Wash.-based Cascadia Research.

“There are many things we do not know about how many contaminants accumulate and might impact marine mammals,” Calambokidis said. “This is valuable especially because there are so many chemicals that are used by humans and enter the environment and many are not tested for.”



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