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Canada is coldest when Earth is closest to the sun

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This Saturday and Sunday, Earth will be 147.091 million kilometres from the sun.


Winter scenery at the top of Blue Mountain in Ontario in January 2019.

We continue Postmedia’s annual look at what makes this season special, a time when nature is not just shutting down for three months. Today the Science of Winter asks why the seasons are not all equal.

Here’s a paradox about winter: This is the season that brings us the closest to the sun, and yet it also brings us the deepest cold.

Another oddity: winter is the shortest season. You’d think they would each be one-quarter of 365 days, but no.

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We’ll run some numbers. But, first, take a look at the shape of Earth’s orbit, which is the root cause of the whole business of seasons.

Our axis (from pole to pole) has a tilt when compared to the movement of our planet. In our northern summer, the North Pole is tilted toward the sun. In our winter, it is tilted away from the sun.

But there’s another oddity, too: Earth does not run in a nice, neat circle around the sun. Our orbit is an ellipse, basically an oval much like the capital O on the Ottawa Senators’ sweaters.

Different points along that oval are different distances from the sun.

One time of year — early in Canada’s winter — brings us to the point in our orbit that is closest to the sun. Later we will be farthest from the sun in early summer.


Winter scenery at the top of Blue Mountain in Ontario in January 2019.

Veronica Henri /

Postmedia

So, about those numbers.

This Saturday and Sunday mark the time of our closest approach. Earth will be 147.091 million kilometres from the sun.

By early July, we will be at our farthest point, of 152.095 million kilometres. That’s five million kilometres farther away than we are today.

Another way to see it: Australia is closer to the sun during its summer (i.e. today) than we are in our summer.

As well, the fact that we are tilted away from the sun this month matters far more than our actual distance from the sun. We aren’t getting sunlight, so it’s cold.

(Anyone who wants to check the daily distance from the sun can find a dandy chart at timeanddate.com. It shows distances, length of daylight and height of sun in the sky.)

The second point is that the seasons are all different lengths, as measured by the dates of equinoxes and solstices. Rounding the seasons to the nearest whole day, our (northern) winter is 89 days, while autumn is 90 days, spring is 93 days and summer is 94 days. (This comes to 366 days because of rounding.)


The sun rises over the mountains and the valley of the river Inn near the small village of Telfs, Austria, on New Year’s Day.

CHRISTOF STACHE /

AFP via Getty Images

The reason: During our winter, Earth is close to the sun and this makes it go faster in its orbit. The sun’s gravity is pulling us closer, making us speed up. Our summer is a period when Earth is slowing down in its orbital movement, fighting the sun’s pull as it moves farther away, so it takes longer to go through that season.

An analogy is a comet, which flies a much more exaggerated ellipse than we do. Comets spend decades or even centuries in the outer darkness of the solar system and then, when they approach the sun, they accelerate all the way in, loop around the sun like Captain Kirk’s ship in Star Trek IV and are often gone far away in a few weeks.

 

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Marine plankton could act as alert in mass extinction event: UVic researcher – Langley Advance Times

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A University of Victoria micropaleontologist found that marine plankton may act as an early alert system before a mass extinction occurs.

With help from collaborators at the University of Bristol and Harvard, Andy Fraass’ newest paper in the Nature journal shows that after an analysis of fossil records showed that plankton community structures change before a mass extinction event.

“One of the major findings of the paper was how communities respond to climate events in the past depends on the previous climate,” Fraass said in a news release. “That means that we need to spend a lot more effort understanding recent communities, prior to industrialization. We need to work out what community structure looked like before human-caused climate change, and what has happened since, to do a better job at predicting what will happen in the future.”

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According to the release, the fossil record is the most complete and extensive archive of biological changes available to science and by applying advanced computational analyses to the archive, researchers were able to detail the global community structure of the oceans dating back millions of years.

A key finding of the study was that during the “early eocene climatic optimum,” a geological era with sustained high global temperatures equivalent to today’s worst case global warming scenarios, marine plankton communities moved to higher latitudes and only the most specialized plankton remained near the equator, suggesting that the tropical temperatures prevented higher amounts of biodiversity.

“Considering that three billion people live in the tropics, the lack of biodiversity at higher temperatures is not great news,” paper co-leader Adam Woodhouse said in the release.

Next, the team plans to apply similar research methods to other marine plankton groups.

Read More: Global study, UVic researcher analyze how mammals responded during pandemic

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Scientists Say They Have Found New Evidence Of An Unknown Planet… – 2oceansvibe News

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In the new work, scientists looked at a set of trans-Neptunian objects, or TNOs, which is the technical term for those objects that sit out at the edge of the solar system, beyond Neptune

The new work looked at those objects that have their movement made unstable because they interact with the orbit of Neptune. That instability meant they were harder to understand, so typically astronomers looking at a possible Planet Nine have avoided using them in their analysis.

Researchers instead looked towards those objects and tried to understand their movements. And, Dr Bogytin claimed, the best explanation is that they result from another, undiscovered planet.

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The team carried out a host of simulations to understand how those objects’ orbits were affected by a variety of things, including the giant planets around them such as Neptune, the “Galactic tide” that comes from the Milky Way, and passing stars.

The best explanation was from the model that included Planet 9, however, Dr Bogytin said. They noted that there were other explanations for the behaviour of those objects – including the suggestion that other planets once influenced their orbit, but have since been removed – but claim that the theory of Planet 9 remains the best explanation.

A better understanding of the existence or not of Planet 9 will come when the Vera C Rubin Observatory is turned on, the authors note. The observatory is currently being built in Chile, and when it is turned on it will be able to scan the sky to understand the behaviour of those distant objects.

Planet Nine is theorised to have a mass about 10 times that of Earth and orbit about 20 times farther from the Sun on average than Neptune. It may take between 10,000 and 20,000 Earth years to make one full orbit around the Sun.

You may be tempted to ask how an entire planet could ‘hide’ in our solar system when we have zooming capabilities such as the new iPhone 15 has, but consider this: If Earth was the size of a marble, the edge of our solar system would be 11 kilometres away. That’s a lot of space to hide a planet.

[source:independent]

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Dragonfly: NASA Just Confirmed The Most Exciting Space Mission Of Your Lifetime – Forbes

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NASA has confirmed that its exciting Dragonfly mission, which will fly a drone-like craft around Saturn’s largest moon, Titan, will cost $3.35 billion and launch in July 2028.

Titan is the only other world in the solar system other than Earth that has weather and liquid on the surface. It has an atmosphere, rain, lakes, oceans, shorelines, valleys, mountain ridges, mesas and dunes—and possibly the building blocks of life itself. It’s been described as both a utopia and as deranged because of its weird chemistry.

Set to reach Titan in 2034, the Dragonfly mission will last for two years once its lander arrives on the surface. During the mission, a rotorcraft will fly to a new location every Titan day (16 Earth days) to take samples of the giant moon’s prebiotic chemistry. Here’s what else it will do:

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  • Search for chemical biosignatures, past or present, from water-based life to that which might use liquid hydrocarbons.
  • Investigate the moon’s active methane cycle.
  • Explore the prebiotic chemistry in the atmosphere and on the surface.

Spectacular Mission

“Dragonfly is a spectacular science mission with broad community interest, and we are excited to take the next steps on this mission,” said Nicky Fox, associate administrator of the Science Mission Directorate at NASA Headquarters in Washington. “Exploring Titan will push the boundaries of what we can do with rotorcraft outside of Earth.”

It comes in the wake of the Mars Helicopter, nicknamed Ingenuity, which flew 72 times between April 2021 and its final flight in January 2023 despite only being expected to make up to five experimental test flights over 30 days. It just made its final downlink of data this week.

Dense Atmosphere

However, Titan is a completely different environment to Mars. Titan has a dense atmosphere on Titan, which will make buoyancy simple. Gravity on Titan is just 14% of the Earth’s. It sees just 1% of the sunlight received by Earth.

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The atmosphere is 98% nitrogen and 2% methane. Its seas and lakes are not water but liquid ethane and methane. The latter is gas in Titan’s atmosphere, but on its surface, it exists as a liquid in rain, snow, lakes, and ice on its surface.

COVID-Affected

Dragonfly was a victim of the pandemic. Slated to cost $1 billion when it was selected in 2019, it was meant to launch in 2026 and arrive in 2034 after an eight-year cruise phase. However, after delays due to COVID, NASA decided to compensate for the inevitable delayed launch by funding a heavy-lift launch vehicle to massively shorten the mission’s cruise phase.

The end result is that Dragonfly will take off two years later but arrive on schedule.

Previous Visit

Dragonfly won’t be the first time a robotic probe has visited Titan. As part of NASA’s landmark Cassini mission to Saturn between 2004 and 2017, a small probe called Huygens was despatched into Titan’s clouds on January 14, 2005. The resulting timelapse movie of its 2.5 hours descent—which heralded humanity’s first-ever (and only) views of Titan’s surface—is a must-see for space fans. It landed in an area of rounded blocks of ice, but on the way down, it saw ancient dry shorelines reminiscent of Earth as well as rivers of methane.

The announcement by NASA makes July 2028 a month worth circling for space fans, with a long-duration total solar eclipse set for July 22, 2028, in Australia and New Zealand.

Wishing you clear skies and wide eyes.

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