Pluto’s famous heart powers icy winds on the dwarf planet | Live Science

Pluto’s icy heart is beating.

The dwarf planet’s famous heart-shaped feature, which NASA’s discovered during its epic July 2015 flyby, drives atmospheric circulation patterns on Pluto, a new study suggests.

Most of the action comes courtesy of the heart’s left lobe, a 600-mile-wide (1,000 kilometers) nitrogen-ice plain called Sputnik Planitia. This exotic ice vaporizes during the day and condenses into ice again at night, causing nitrogen winds to blow, the researchers determined. ( is dominated by nitrogen, like Earth’s, though the dwarf planet’s air is about 100,000 times thinner than the stuff we breathe.)  

These winds carry heat, particles of haze and grains of ice westward, staining the ices there with dark streaks.

“This highlights the fact that Pluto’s atmosphere and winds — even if the density of the atmosphere is very low — can impact the surface,” study lead author Tanguy Bertrand, an astrophysicist and planetary scientist at NASA’s Ames Research Center in California, . 

And that westward direction is interesting in itself, considering that Pluto spins eastward on its axis. The dwarf planet’s atmosphere therefore exhibits an odd “retrorotation,” study team members said.

Bertrand and his colleagues studied data gathered by New Horizons during the probe’s 2015 close encounter. The researchers also performed computer simulations to model Pluto’s nitrogen cycle and weather, especially the dwarf planet’s winds.

This work revealed the likely presence of westerly winds — a high-altitude variety that races along at least 2.5 miles (4 kilometers) above the surface and a fast-moving type closer to the ground that follows Sputnik Planitia’s western edge.

That edge is bounded by high cliffs, which appear to trap the near-surface winds inside the Sputnik Planitia basin for a spell before they can escape to the west, the new study suggested.

“It’s very much the kind of thing that’s due to the topography or specifics of the setting,” planetary scientist Candice Hansen-Koharcheck, of the Planetary Science Institute in Tucson, Arizona, said in the same statement. 

“I’m impressed that Pluto’s models have advanced to the point that you can talk about regional weather,” added Hansen-Koharcheck, who was not involved in the new study.

New Horizons’ Pluto flyby revealed that the dwarf planet is far more complex and diverse than anyone had thought, featuring towering water-ice mountains and weird “bladed” terrain in addition to the photogenic heart (whose official name, Tombaugh Regio, honors the discoverer of Pluto, ).

The , which was published online Tuesday (Feb. 4) in the Journal of Geophysical Research: Planets, reinforces and extends that basic message.

“Sputnik Planitia may be as important for Pluto’s climate as the ocean is for Earth’s climate,” Bertrand said. “If you remove Sputnik Planitia — if you remove the heart of Pluto — you won’t have the same circulation.”

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112-Year-Old Bigmouth Buffalo Is World’s Oldest Freshwater Bony Fish

The bigmouth buffalo, a North American species of freshwater fish, can live for more than 100 years – that’s over 80 years longer than previously thought. The fish has now been crowned the longest-lived freshwater teleost (a vast group of bony fishes) and the oldest age-validated freshwater fish on the planet.

Until now, the bigmouth buffalo (Ictiobus cyprinellus) was thought to live to about 26 years of age. That was according to a 1999 study based on fish found in Oklahoma. The team behind the new study, published in Communications Biology, turned to Minnesota’s bigmouth buffalofish (the city of Buffalo in Minnesota is named after the species) and determined their ages using bomb radiocarbon dating.

This involved looking at levels of carbon-14 in the fish’s otoliths, tiny structures found in the inner ear that continue to grow throughout the fish’s life. Levels of carbon-14 can be used to determine age thanks to the atomic bomb tests carried out in the mid-20th century. These tests massively increased the amount of this radioactive isotope in our environment before it declined once more to pre-bomb test levels.

The researchers, led by North Dakota State University, looked at almost 400 fish and found that five were older than 100 years of age. The oldest bigmouth buffalo was 112, while nearly 200 fish were in their 80s or 90s. The fact that so many of the fish studied were very old (85-90 percent were over 80 in multiple populations) suggests that the species has had little success reproducing for many decades. The study authors note that this is likely due to the construction of dams during the 1930s.

Alec Lackmann
A bigmouth buffalo. Alec Lackmann

The largest of the buffalofish, the bigmouth buffalo can grow to an impressive 1.2 meters (4 feet) in length and weigh as much as 29 kilograms (65 pounds). The species is very important to the health of the local ecosystem because it competes with invasive species like the silver carp and bighead carp for resources, keeping these creatures in check. Bigmouth buffalofish also eat invasive zebra mussels in their larval stages, providing an important ecological service as these shellfish cause economic and ecological damage and affect swimmers and boats.

Unfortunately, bigmouth buffalo are struggling to overpower their invasive competitors, and thanks to largely unregulated fishing, the species is in decline. The researchers note that this lack of regulation must be addressed swiftly to preserve this environmentally and economically important species.

“We need to start recognizing bigmouth buffalo for the native, ecological asset that they are,” said lead author Alec R. Lackmann in a statement. “Our neglect of under-appreciated, native species needs to be addressed immediately. Our research has shown that the bigmouth buffalo is one of the longest-lived vertebrates. That alone is something worth preserving and understanding. Among freshwater fish, the bigmouth buffalo is quite exceptional, and they deserve some protection like many other native species in North America have already achieved. The bigmouth buffalo could be treasured one day.” 

Alec R. Lackmann
These large orange spots are a sign of old age. Alec Lackmann

 

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