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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

Today’s letters: ‘Visionary’ plans don’t always work in Ottawa

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The opinion piece written by Tobi Nussbaum, CEO of the NCC, declares that a “bold, visionary transit plan” would showcase the capital.

As a long-term resident of Ottawa, I’ve had it with visionary plans. In the 1950s, the streetcars serving Ottawa so well were sent to the scrapyards. In the early ’60s, Queensway construction bulldozed established neighbourhoods and ripped the city apart. Later in the decade, the downtown railway station, which could have formed the hub of a commuter network, was relocated to the suburbs. These actions, in the name of “progress,” were undertaken with the “vision” to make Ottawa a car-reliant city.

Now we have an LRT, built just in time for most people to realize that they do not have to go downtown as they can work from home.

Current thinking is pushing a new “link” between Ottawa and Gatineau, with yet more expensive and disruptive infrastructure projects being touted, including a tramway or another tunnel under the downtown core.

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Ecology

That was then: Biggest earthquake since 1653 rocked Ottawa in 1925

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A regular weekly look-back at some offbeat or interesting stories that have appeared in the Ottawa Citizen over its 175-year history. Today: The big one hits.

The Ottawa Senators were playing a Saturday night game against the Montreal Canadiens at the Auditorium, the score tied 0-0 halfway through the second period. Sens’ rookie Ed Gorman and the Habs’ Billy Boucher had just served penalties for a dustup when the building began to make “ominous creaking sounds.” A window crashed to the ground.

Nearby, at Lisgar Collegiate, all eyes were on teenager Roxie Carrier, in the role of Donna Cyrilla in the musical comedy El Bandido. She had the stage to herself and was singing “Sometime” when the building rocked, the spotlight went out, and someone in the audience yelled “Fire!”

At a home on Carey Avenue, one woman’s normally relaxed cat suddenly arched its back, rushed around the room two or three times, spitting angrily, and climbed up the front-window curtains.

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Ecology

Ottawa delays small nuclear reactor plan as critics decry push for new reactors

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TORONTO — Canadians will have to wait a little while longer to see the federal government’s plan for the development of small nuclear reactors, seen by proponents as critical to the country’s fight against global warming.

Speaking at the opening of a two-day virtual international conference on Wednesday, the parliamentary secretary to the minister of natural resources said the plan will lay out key actions regarding the reactors. Its launch, Paul Lefebvre said, would come in the next few weeks.

“We’re still putting the finishing touches on it,” Lefebvre said. “The action plan is too important to be rushed.”

Small modular reactors — SMRs — are smaller in size and energy output than traditional nuclear power units, and more flexible in their deployment. While conventional reactors produce around 800 megawatts of power, SMRs can deliver up to 300 megawatts.

Proponents consider them ideal as both part of the regular electricity grid as well as for use in remote locations, including industrial sites and isolated northern communities. They could also play a role in the production of hydrogen and local heating.

“SMRs will allow us to take a bold step of meeting our goal of net-zero (emissions) by 2050 while creating good, middle class jobs and strengthening our competitive advantage,” said Lefebvre.

Natural Resources Minister Seamus O’Regan had been scheduled to speak at the conference but did not due to a family emergency.

Industry critics were quick to pounce on the government’s expected SMR announcement. They called on Ottawa to halt its plans to fund the experimental technology.

While nuclear power generation produces no greenhouse gas emissions, a major problem facing the industry is its growing mound of radioactive waste. This week, the government embarked on a round of consultations about what do with the dangerous material.

Dozens of groups, including the NDP, Bloc Quebecois, Green Party and some Indigenous organizations, oppose the plan for developing small modular reactors. They want the government to fight climate change by investing more in renewable energy and energy efficiency.

“We have options that are cheaper and safer and will be available quicker,” Richard Cannings, the NDP natural resources critic, said in a statement.

Lefebvre, however, said the global market for SMRs is expected to be worth between $150 billion and $300 billion a year by 2040. As one of the world’s largest producers of uranium, Canada has to be part of the wave both for economic and environmental reasons, he said.

“There’s a growing demand for smaller, simpler and affordable nuclear technology energy,” Lefebvre said.

Joe McBrearty, head of Canadian Nuclear Laboratories, told the conference the company had signed a host agreement this week with Ottawa-based Global First Power for a demonstration SMR at its Chalk River campus in eastern Ontario. A demonstration reactor will allow for the assessment of the technology’s overall viability, he said.

“When talking about deploying a new technology like an SMR, building a demonstration unit is vital to the success of that process,” McBrearty said. “Most importantly, it allows the public to see the reactor, to kick the tires so to speak, and to have confidence in the safety of its operation.”

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