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Life Might Exist On The New Planet Discovered Around Barnard’s Star

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An artist’s interpretation of what Barnard’s star b, a super-Earth recently discovered just six light-years from Earth, may look like. (Credit: ESO/M. Kornmesser)

An artist’s interpretation of what Barnard’s star b, a super-Earth recently discovered just six light-years from Earth, may look like. (Credit: ESO/M. Kornmesser)

Late last year, astronomers announced that they’d found a super-Earth around Barnard’s star – one of the closest suns to our own. The discovery of a planet just six light-years away was enough to excite astronomers and the public alike. However, the researchers who found the planet said that they suspected the icy world couldn’t support life.

But now, a group of astronomers are saying such pessimism may be premature. On Earth, geothermal vents produce heat and create unique environments where life thrives in places otherwise difficult to eke out a living – like the frigid, dark deep of the oceans. The team says similar processes could be at work on this world, which is officially cataloged as Barnard b.

Barnard’s star is a low-mass red dwarf , which means it’s small, ancient, and only emits a fraction of the energy our sun puts out. The planet itself is about three times the mass of Earth and orbits the star every 233 days. So, because of its distant orbit around a tiny star, the planet should be a pretty frigid place where water would freeze on the surface.

But what about the water below the surface? On Thursday morning at the 233rd Meeting of the American Astronomical Society in Seattle, Washington, a team of astronomers rekindling the planet’s potential for habitability. They said that if the world also has a large iron/nickel core and enough geothermal activity, features such as volcanic plumes and vents could create “life zones” of liquid water under the world’s frozen surface.

In the Zone

These life zones, according to study co-author Edward Guinan of Villanova University, may be “akin to subsurface lakes found in Antarctica” here on Earth. The closest analog, he said, is Lake Vostok, which sits far below the ice in Antarctica, yet doesn’t freeze over because it’s heated by volcanism. Scientists recently found evidence of life there. Guinan also compared these zones to regions near potential hydrothermal vents on Europa, which very likely holds a completely liquid ocean underneath an icy shell.

Europa, however, is heated by the pull of Jupiter’s hulking gravity, as well as gravity from its neighboring moons. On Barnard b, the heat would come from the planet itself. Though the team estimates the age of Barnard’s star – and its planet – to be about twice that of our own sun and solar system, if the planet hosts a large, hot iron core, its greater mass may also give it enhanced and long-lasting geothermal activity. However, Guinan pointed out during the conference that “there’s not a lot known about super-Earths. Our models are all over the place.”

A liquid iron core, the team’s work states, could further offer protection from its sun’s deadly activity, as M-dwarf stars are known to bathe their surroundings with radiation that can strip their planets’ atmospheres away, particularly early in their lifetimes.

Cosmic Calculations

The team targeted Barnard’s star as part of the Villanova Living with a Red Dwarf program, which has been ongoing for the past 20 years. “We were waiting for a planet to be discovered around Barnard’s star,” Guinan said. The researchers determined the age of the star and planet using data stretching back to 2003. Based on measurements of the star’s brightness over time, they determined that it rotates about once every 142 days. From there, they calculated its age – about 8.6 billion years, or roughly twice the sun’s age – using a relationship called the period-age-activity relation for red dwarfs, which links a star’s rotational rate and activity levels to its age.

The team also calculated the amount of X-ray and ultraviolet radiation the star’s planet would receive at its distance of 0.4 astronomical units (1 astronomical unit, or AU, is equal to the Earth-sun distance) to determine the effects on any atmosphere Barnard b might host. They note that this effect is largest when the star is young and more active, and diminishes as the star ages. When an M-dwarf like Barnard’s star is young, they said, it both rotates faster and puts out ultraviolet and X-ray light that is tens to hundreds of times stronger, respectively, than when it is older. Such high levels of radiation would likely damage or destroy the atmosphere on any planets circling it. On the other hand, the young Barnard’s star would have also been more luminous, warming its planet, which was closer in the past, enough for an atmosphere composed of greenhouse gases – however limited in lifetime – to perhaps maintain a surface temperature that could support liquid water, if only briefly.

Currently, Barnard b only receives about 2 percent the radiation Earth receives from the Sun, and is a cold world with a surface temperature of nearly -275 degrees Fahrenheit (-170 degrees Celsius). If it does have any water left today, it would be frozen on the surface, with only the ocean depths potentially habitable in limited zones warmed by vents.

However, there is another possibility: Barnard b could actually be more massive than currently believed. If its mass is truly greater, more than seven Earth masses, it would have enough gravity to hold onto a thick atmosphere of hydrogen and helium, making it not a terrestrial super-Earth, but an ice giant, mini-Neptune instead. An ice giant, Guinan said in the press conference, “would preclude life” unless the planet has a Europa-like moon with tidal heating, which is where life might instead be found in the system, in that case.

Nonetheless, Barnard b remains an excellent candidate for up-and-coming bleeding-edge imaging techniques and the next generation of instruments in development.

“It is on the hairy edge of being imageable,” Guinan said, and “beyond the edge of what can presently be imaged.”

Although more information is needed to determine Barnard b’s mass and potential for habitability, future work may open the door to better understand super-Earths and what their environments – and inhabitants – could be like.

 

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Ecology

Globe Climate: Canada’s resource reckoning is coming

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Good afternoon, and welcome to Globe Climate, a newsletter about climate change, environment and resources in Canada.

This afternoon, the Alberta government announced that it is restoring a coal mining policy it revoked last spring. At the time, the move provoked a widespread public backlash detailed by The Globe. The original decision, which opened up more than 1.4 million hectares to exploration, was made without public consultation. Premier Jason Kenney previously defended the changes.

Lots more on coal and Canada’s resources industry in this week’s newsletter edition.

Now, let’s catch you up on other news.

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Ecology

‘Incredibly destructive’: Canada’s Prairies to see devastating impact of climate change

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As the climate continues to warm at an alarming rate, experts warn if dramatic steps to mitigate global warming are not taken, the effects in Canada’s Prairie region will be devastating to the country’s agriculture sector.

According to Environment and Climate Change Canada, the country is warming, on average, about double the global rate.

Scientists with the National Oceanic and Atmospheric Administration in the U.S. recently found 2020 was earth’s second-hottest year on record, with the average land and ocean surface temperature across the globe at 0.98 of a degree C above the 20th-century average.

However, the agency found the northern hemisphere saw its hottest year on record, at 1.28 degrees C above the average.

“(In Canada) we are looking at about 6.4C degrees of warming this century, which isn’t much less than one degree per decade, which is just a terrifying rate of warming,” Darrin Qualman, the director of climate crisis policy and action at the National Farmer’s Union said.

Qualman said there is “massive change coming” to Canada’s Prairies, which will be “incredibly destructive.”

“It’s not going too far to say that if we made that happen, parts of the Prairies wouldn’t be farmable anymore,” he said.

According to the federal government, in 2018 Canada’s agriculture and agri-food system generated $143 billion, accounting for 7.4 per cent of the country’s GDP.

The sector employed 2.3 million people in 2018. The majority of the 64.2 million hectares of farmland in Canada is concentrated in the Prairies and in southern Ontario.

The effects of climate change are already being felt on the ground in the Prairies, Qualman said, adding that the NFU has already heard from farmers complaining of “challenging weather.”

“People are sharing pictures of flattened crops and buildings, et cetera, that have been damaged,” he said. “And we’re still at the beginning of this.”

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Ecology

Insect-based dog food aims to cut your pet’s carbon pawprint

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Meat has an enormous carbon footprint, with livestock liable for about 15 per cent of worldwide emissions, as we have beforehand mentioned on this e-newsletter. That is prompted specialists to suggest consuming much less meat for sustainability (and well being) causes.

However what about your pet? One research discovered that the methane and nitrous oxide emissions generated by canine and cat meals within the U.S. alone had been equal to about 64 million tonnes of CO2, or roughly the quantity produced by 13.6 million automobiles. And it might be getting worse, with a development towards feeding pets “human-grade” meat.

That is prompted some pet meals makers to look to lower-carbon protein sources — together with bugs.

Research present that producing insect-based meals requires far much less feed, land and water and generates far fewer greenhouse fuel emissions per kilogram than meats comparable to beef, pork or rooster.

That is one of many causes increasingly more pet meals containing insect protein are hitting the market. Purina, a model owned by multinational Nestlé, launched a line of canine and cat meals containing black soldier fly larvae in Switzerland in November.

In Canada, Montreal-based Wilder Harrier began promoting canine treats made with cricket protein in 2015 and pet food made with black soldier fly larvae in 2019. It plans to broaden to launch a line of insect-based cat treats later this yr and cat meals in 2022 due to “a ton of demand,” mentioned firm co-founder Philippe Poirier.

Wilder Harrier initially labored with animal nutritionists on insect-based merchandise to unravel a unique downside — specifically, the founders’ canines had allergy symptoms to frequent meats utilized in canine meals. Poirier mentioned now about half its prospects hunt down the product due to their pets’ allergy symptoms and about half for environmental causes.

Dr. Cailin Heinze, a U.S.-based veterinary nutritionist licensed by the American School of Veterinary Vitamin, has written concerning the environmental influence of pet meals. She mentioned we’re typically “not as involved as we probably ought to [be]” concerning the environmental footprint of pets.

Alternatively, she famous that the longer-term influence of newer diets, comparable to vegan meals and people containing bugs, hasn’t been nicely examined in comparison with conventional pet meals.

Maria Cattai de Godoy, an assistant professor of animal sciences on the College of Illinois who research novel proteins for pet meals (together with bugs, yeast and plant-based substances), mentioned such substances are rigorously examined to find out their security and diet earlier than being added to pet meals. 

“This can be a very extremely regulated trade,” she mentioned, however admitted it is also evolving.

Relating to bugs, she mentioned constructive information “reveals promise in direction of utilizing them increasingly more in pet meals.” Insect-based proteins have additionally earned the endorsement of the British Veterinary Affiliation, which says some insect-based meals could also be higher for pets than prime steak.

However Godoy famous that there isn’t any one-size-fits-all resolution, and pet homeowners ought to take into consideration the wants of their very own particular person pet and analysis whether or not a specific weight loss plan can be appropriate.

She mentioned that other than the kind of protein, issues like packaging and manufacturing strategies may also make a distinction. For instance, utilizing meat byproducts that may in any other case turn into waste would not drive elevated meat manufacturing the identical approach as utilizing human-grade meat.

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