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Watching the skies: Dal Planetarium forges community connections for Perseid meteor shower

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Here’s something you might not know about meteor showers: those beams of light that you see dashing across the night sky? They’re tiny — no more than specks of dust, really.

“They’re particles about the size of a grain of sand,” says Stephen Payne, senior instructor in the Department of Physics and Atmospheric Science and manager of the Halifax Planetarium at Dalhousie. “When they strike the Earth’s atmosphere, they heat up and give off light.”

This weekend marks the peak of the Perseid meteor shower, perhaps the most popular stargazing event of the year. At times, there may be as many as 60 meteors visible in the sky per hour, making it one of the most active and visible meteor showers of the year.

And for the third year in a row, Payne and his team are hitting the road to Nova Scotia’s Eastern Shore to help others learn more about the meteor shower, the night sky and how to become better star watchers.

Sharing science

The Planetarium team, including Kaja Rotermund and Tolson Winters alongside Dr. Payne, are featured as part of the Sealight Skylight Festival in Ship Harbour on August 11 and 12.

Organized by the Deanery Project (a not-for-profit cooperative focusing on the environment, youth and community, natural building and the arts), the event links together the peak of the Perseid shower with an abundance of bioluminescence in Ship Harbour, making it a great opportunity to experience — and learn about — some of our universe’s natural wonders.

Each evening, the Planetarium team will lead a short presentation on the night sky and the meteor shower itself, prior to the actual observation (complete with telescopes).

“We focus on showing them how they can find things on their own, and how to remember how to find them,” says Rotermund. “It’s called ‘star hopping,’ making it easier for them to find the same things the next night or in the future when they’re doing it on their own.”

Of course, the shower itself is the main attraction: an event caused by the debris of the comet Swift-Tuttle, which orbits the sun every 133 years.

“Comets are basically dirty snowballs,” says Payne, “and their ices partially evaporate near the Sun, leaving solid particles behind. The Earth then passes through that debris field every year in July-August.”

As for why the Perseids seem to capture people’s imaginations each year,  Payne credits the timing. “It’s summertime, people are outside, it’s warm and there’s more time to look up,” he says. “It’s also a fairly active shower event — the count rate of meteors can be quite high.”

Connecting with the natural world

With a good weather forecast for the weekend, the team is hoping for a quality viewing experience. (It’s been somewhat cloudy at the Perseid’s peak the past two years.)

The team will also do a presentation on bioluminescence, paired with a viewing in the harbour, as well as hands-on astronomy activities before dusk and during the daytime on Sunday, perfect for kids and families.

They’re also not the only Dal connection to the festival: recent Master’s of Environmental Studies grad shalan joudry (who also performed as part of the Bicentennial Launch event for Dal 200), is a new addition to the event this year for Sunday’s activities, presenting on Mi’kmaw ecology in the afternoon and sharing a Mi’kmaw night story during the evening.

“I will be talking about my understanding and work as a Mi’kmaw ecologist and what that means to me,” says joudry about her presentation. “I will share some of the teachings that the Elders shared with me through my research process and my work life, but then also describe what I find as differences and complementary ways of seeing and learning, through Mi’kmaw and mainstream science.”

For the Dal Physics team, the festival is an opportunity to engage people of all ages in science.

“It’s great to see the young people engaged, but it’s always interesting to see how enamored the parents are as well,” says Rotermund. “They’re just as excited.”

“It’s a great unifier, too,” adds Winters. “You can do most of the sciences with astronomy. There’s obviously a lot of physics, a lot of chemistry, biology, geography and the list just keeps going. And it really unifies people because everyone loves space.”

The Sealight Skylight Festival takes place on Saturday, August 11 from 7:30-11 p.m. and on Sunday, August 12 from 2:30-11:30 p.m. in Ship Harbour, Nova Scotia. For full details, visit the Deanery Project website. You can also learn more about the Halifax Planetarium at astronomynovascotia.ca.


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Global warming 'pause' about to end, raise Earth's temperatures further

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The past four years have been the hottest on record, but new research shows the Earth was actually in a global warming "hiatus" that is about to end. And when it does, natural factors are likely to help an already warming planet get even hotter over the next four years, according to a new forecasting model.

Rising CO2 levels have caused the temperature of the planet to rise, said lead author of the Nature Communications paper, Florian Sevellec, a professor of ocean and Earth science at the University of Southampton in the United Kingdom and a scientist at France's National Centre for Scientific Research.

Records show 2017 marked the 41st consecutive year with global temperatures at least marginally above the 20th century average, with 2016 being the record-holder. And it's likely that global temperatures in 2018 will be another one for the record books.

However, Earth's natural cycles, which include events like El Nino and La Nina, can also influence global temperatures.

And while Earth seems to have been running a fever for almost a decade straight, the natural cycles have been in their "cooling" phase, Sevellec says — and that's about to shift, raising the global temperature further.

"It will be even warmer than the long-term global warming is inducing," Sevellac said. 

This cooler phase of the planet's natural variability is responsible for what is often referred to as a global warming "pause" or "hiatus." While the planet continued to warm, it seemed to plateau. 

But that had to end sometime.

John Fyfe, senior research scientist at the Canadian Centre for Climate Modelling and Analysis at Environment and Climate Change Canada, says that multiple issues were at play but mainly the natural variability of the planet.

"I'm not at all surprised by the results," Fyfe said of the new study, in which he was not involved. "And the reason for that is that we have gone down this long slowdown period primarily due to internal variability, and the expectation was that we'd come out of it."

With the Earth continuing to warm, the chances increase for events like heat waves. (Yves Herman/Reuters)

Though CO2 levels were still increasing in Earth's atmosphere, natural cycles like the El Nino Southern Oscillation (ENSO) in the Pacific Ocean were cooler than normal and offset rising global temperatures. 

But, Sevellac says, "the long-term trend was building up."

This doesn't mean, however, that we can point to a specific area and better forecast, say, heat waves. Instead, this is a global measurement. But with the Earth continuing to warm, the chances increase for these events.

And global warming doesn't mean that every location on the planet warms uniformly — there are some regions that can be colder than normal — nor does it mean that each year is hotter than the previous one. Instead, it's an overall trend that can play out within a decade or more, with the temperature of the entire planet rising over time.

Probability vs. certainty

In order to test the ability to predict future climate outcomes, the model employs a method that looks backward. In this case, it was able to predict with accuracy the climate slowdown that occurred around 1998 and onward to roughly 2014.

But it's important to note that this is a probability, not a certainty.

The model shows a higher temperature than what was predicted based just on the increased CO2: the probability is 58 per cent for global surface air temperature and 75 per cent for sea surface temperatures.

"Because we tested it over the last century, we know that we are accurate for the likelihood," Sevellac says. "But the likelihood doesn't mean it will occur … there exists a small chance of being cold."

We could already be seeing a shift: after a record-breaking El Nino year just two years ago in 2016 — which caused heat waves, coral bleaching, drought and flooding around the world — the U.S. Climate Prediction Center is forecasting a 70 per cent chance that another one is on its way this winter

There's no telling how long the cycle will last, if it does manifest: it could be five years or 10. But what's important to note, Sevellac says, is that rising CO2 is still the key player in the warming of the planet.

While the study shows that the Earth's natural variability can have an influence in the short term, Sevellac says, "I think it's also a demonstration that global warming will still be there after all this natural variability."

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Scientists Develop Lab-Made Mineral That Will Suck CO2 From The Atmosphere

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Magnesite sample

A dream solution is that humans could develop a way to suck as much CO2 from the atmosphere as we release, and combined with greenhouse gas emission reductions, we could slow or reverse the tide of climate change.

Scientists have found a way to rapidly create the mineral magnesite in a lab both inexpensively and potentially at scale. This could be coupled with carbon sequestration, a process in which carbon is injected and stored underground, typically in depleted oil and gas fields. Reducing the concentration of CO2 in the atmosphere can be both a result of reducing input as well as increasing output of carbon dioxide from the atmosphere.

The research was presented recently at the Goldschmidt conference in Boston by Professor Ian Power of Trent University, Ontario, Canada. Their findings outline a novel way to rapidly produce magnesite inexpensively and at room temperature, allowing for the expansion of the process to an industrial scale.

If implemented at scale, the potential for another tool of CO2 removal via magnesite becomes a possibility, removing carbon dioxide from the atmosphere and storing it long-term in the mineral magnesite.

Below is a breakdown of the potential chemical reaction by which carbon dioxide can be removed from the atmosphere to create magnesite.

CO2+ H2O→H2CO3→ H++ HCO3

Mg+2+HCO3− →MgCO3+H+

To explain the above equations, carbon dioxide from the atmosphere is injected into water, which is then dissociated to form carbonic acid. From there, elemental magnesium combines with the carbonic acid to form magnesite (MgCO3).

At this time, most carbon capture and storage options are difficult to implement at scale due to high costs and difficulties scaling. With this new method, however, the rate of magnesite formation goes from hundreds to thousands of years in nature to within 72 days in a lab and at low temperatures.

Based on previous studies, magnesite can remove about half its weight in carbon dioxide from the atmosphere. Estimates put our current CO2 emissions at about 40 billion tons per year. That would mean to remove the equivalent amount of carbon emitted per year solely through magnesite formation, 80 billion tons would have to be produced per year. It becomes increasingly apparent that this cannot be the only lever we pull in mitigating climate change.

By speeding up the process, magnesite could be a legitimate resource for removing carbon dioxide from the atmosphere. However, the research is still in an experimental phase and will need to be continually tested before it could ever be implemented at industrial scales. In addition, the process will rely on the current price of carbon and financial incentives to remove carbon from the atmosphere.

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Royal Tyrrell research blows swimming dinosaur theory out of the water

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A model of a Spinosaurus is displayed outside the entrance at the National Geographic Society in Washington.


Pablo Martinez Monsivais / AP

New research published by the Royal Tyrrell Museum on Thursday has sunk previous claims that a swimming dinosaur once paddled the rivers of the Earth.

The paper, published in scientific journal PeerJ, uses computer modelling to conclude the Spinosaurus was not adapted to swim as previously thought.

Research published in 2014 by Nizar Ibrahim and others in the journal Science proposed the dinosaur was partly aquatic, meaning it could both swim and walk on land, a first for any dinosaur.

But using different techniques that relied on physics-based testing methods, the Royal Tyrrell Museum’s curator of dinosaurs, Donald Henderson, found that the 95-million-year-old species would not have been able to survive living in water.

Henderson created three-dimensional, digital models of Spinosaurus and other predatory dinosaurs in order to test their centres of mass buoyancy and equilibrium when immersed in water. He also tested the software using models of semi-aquatic animals such as an alligator and emperor penguin, for comparison.


Henderson’s models showed that Spinosaurus could float with its head above water. However, models of other dinosaurs demonstrated similar results.

Courtesy Royal Tyrrell Museum

His models showed the Spinosaurus would have been able to float with its head above water and breath freely, just like other dinosaurs analyzed in the study.

But unlike semi-aquatic animals like alligators, which can easily self-right themselves when tipped to the side in water, the Spinosaurus rolled over onto its side when tipped slightly. The finding implied that the dinosaur species would have easily tipped over in water, forcing it to rely on its limbs to constantly maintain an upright position.

Its centre of mass was also found to be close to its hips, between its hind legs, as opposed to the centre of the torso, which had been proposed by Ibrahim’s 2014 research.


A digital model of the centre of mass of Spinosaurus (illustrated by the black plus symbol located at the hind legs), which is similar to that of other theropods, such as Tyrannosaurus rex.

Courtesy Royal Tyrrell Museum

Henderson’s model found the Spinosaurus to be unsinkable underwater, something that would have severely limited its ability to hunt aquatic prey. This differentiates it from traits commonly demonstrated by living aquatic birds, reptiles and mammals, which can submerse themselves to pursue prey underwater.

The combination of mass close to the hips, an inability to sink underwater, and a tendency to roll onto its side unless constantly resisted by limb use, suggest that Spinosaurus was not specialized for a semi-aquatic mode of life,” the researchers stated.

“Spinosaurus may have been specialized for a shoreline or shallow water mode of life, but it would have still have been a competent terrestrial animal,” added Henderson.

shudes@postmedia.com
Twitter.com/SammyHudes

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