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Photos: Total lunar eclipse, last until 2025, wows space watchers

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On Tuesday, the Moon passed through the shadow of the Earth, creating a total lunar eclipse.

For space watchers down on the ground, it was a rare but exciting opportunity to see a phenomenon that has fascinated humans for millennia.

Where skies were clear, the eclipse was visible throughout North America in the predawn hours, with prime viewing in the West, and across parts of East Asia, Australia and the rest of the Pacific after sunset.

The total phase of the eclipse lasted about one-and-a-half hours. The whole event took about six hours from start to finish.

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A total eclipse occurs when the Sun, Earth and the Moon line up perfectly, casting Earth’s shadow on the Moon. Known as the blood moon, the reddish-orange colour is the result of sunlight scattering off Earth’s atmosphere.

At the peak of the eclipse, the Moon was 390,653km (242,740 miles) away, according to NASA scientists.

It was the second total lunar eclipse this year, with the first one taking place in May. The next total lunar eclipse is in March 2025 but there will be plenty of partial eclipses in the meantime.

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Asteroid's sudden flyby shows blind spot in planetary threat detection – The Globe and Mail

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NASA revealed an asteroid, about the size of a truck, was discovered mere days before it passed Earth on Jan. 26. This diagram made available by NASA shows the asteroid’s estimated trajectory in red, affected by the earth’s gravity, and the orbit of geosynchronous satellites, in green.The Associated Press

The discovery of an asteroid the size of a small shipping truck mere days before it passed Earth on Thursday, albeit one that posed no threat to humans, highlights a blind spot in our ability to predict those that could actually cause damage, astronomers say.

NASA for years has prioritized detecting asteroids much bigger and more existentially threatening than 2023 BU, the small space rock that streaked by 2,200 miles (3,500 kilometres) from the Earth’s surface, closer than some satellites. If bound for Earth, it would have been pulverized in the atmosphere, with only small fragments possibly reaching land.

But 2023 BU sits on the smaller end of a size group, asteroids 5-to-50 metres in diameter, that also includes those as big as an Olympic swimming pool. Objects that size are difficult to detect until they wander much closer to Earth, complicating any efforts to brace for one that could impact a populated area.

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The probability of an Earth impact by a space rock, called a meteor when it enters the atmosphere, of that size range is fairly low, scaling according to the asteroid’s size: a 5-metre rock is estimated to target Earth once a year, and a 50-metre rock once every thousand years, according to NASA.

But with current capabilities, astronomers can’t see when such a rock targets Earth until days prior.

“We don’t know where most of the asteroids are that can cause local to regional devastation,” said Terik Daly, a planetary scientist at the Johns Hopkins Applied Physics Laboratory.

The roughly 20-metre meteor that exploded in 2013 over Chelyabinsk, Russia, is a once-every-100-years event, according to NASA’s Jet Propulsion Laboratory. It created a shockwave that shattered tens of thousands of windows and caused US$33-million in damage, and no one saw it coming before it entered Earth’s atmosphere.

Some astronomers consider relying only on statistical probabilities and estimates of asteroid populations an unnecessary risk, when improvements could be made to NASA’s ability to detect them.

“How many natural hazards are there that we could actually do something about and prevent for a billion dollars? There’s not many,” said Mr. Daly, whose work focuses on defending Earth from hazardous asteroids.

One major upgrade to NASA’s detection arsenal will be NEO Surveyor, a US$1.2-billion telescope under development that will launch nearly a million miles from Earth and surveil a wide field of asteroids. It promises a significant advantage over today’s ground-based telescopes that are hindered by daytime light and Earth’s atmosphere.

That new telescope will help NASA meet a goal assigned by U.S. Congress in 2005: detect 90 per cent of the total expected number of asteroids bigger than 140 metres, or those big enough to destroy anything from a region to an entire continent.

“With Surveyor, we’re really focusing on finding the one asteroid that could cause a really bad day for a lot of people,” said Amy Mainzer, NEO Surveyor principal investigator. “But we’re also tasked with getting good statistics on the smaller objects, down to about the size of the Chelyabinsk object.”

NASA has fallen years behind on its congressional goal, which was ordered for completion by 2020. The agency proposed last year to cut the telescope’s 2023 budget by three-quarters and a two-year launch delay to 2028 “to support higher-priority missions” elsewhere in NASA’s science portfolio.

Asteroid detection gained greater importance last year after NASA slammed a refrigerator-sized spacecraft into an asteroid to test its ability to knock a potentially hazardous space rock off a collision course with Earth.

The successful demonstration, called the Double Asteroid Redirection Test (DART), affirmed for the first time a method of planetary defense.

“NEO Surveyor is of the utmost importance, especially now that we know from DART that we really can do something about it,” Mr. Daly said.

“So by golly, we gotta find these asteroids.”

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‘Green Comet’ Begins Closest Approach To Earth As A ‘Snow Moon’ Shines Near Mars: The Night Sky This Week – Forbes

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Each Monday I pick out the northern hemisphere’s celestial highlights (mid-northern latitudes) for the week ahead, but be sure to check my main feed for more in-depth articles on stargazing, astronomy, eclipses and more.

What To See In The Night Sky This Week: January 30-February 5, 2023

With the possibility of Comet C/2022 E3 (ZTF) becoming a naked-eye object and a full moon occulting the red planet Mars it’s arguably one of the most interesting weeks of 2023 so far, sky-wise. The sight of a comet and a planetary disappearance (though only for some) is also joined by the second full moon of winter and the planet Mercury becoming visible in the predawn sky.

However, don’t forget to observe Venus, which is now shining very brightly in the western sky right after sunset. Venus observing aside, get ready for some early mornings and late evenings, stargazers!

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Monday, January 30, 2023: Moon near Mars

Look high in the southwestern sky tonight and you’ll see a 72%-lit waxing gibbous moon alongside reddish Mars. Slightly to its side will be the sparkling open cluster of stars called the Pleiades or “Seven Sisters.” However, if you live in some southern US states or central America then you will also see the weird sight of the moon occulting the red planet, though only its disappearance—it will reappear only for those in the Pacific region.

Tuesday, January 31, 2023: Mercury in the morning

Today sees Mercury at its Greatest Western Elongation, the point when the innermost planet in the solar system reaches its farthest from the sun from our point of view. Use binoculars to find it in low in the southeastern sky just before sunrise. It will actually be visible slightly higher in the sky on Wednesday and Thursday.

Wednesday, February 1, 2023: A comet at its brightest?

In theory, tonight should see comet C/2022 E3 (ZTF) at its brightest simply because it will be closest to Earth. It should be visible through binoculars and small telescopes and, just maybe, with the naked eye—though likely only under very dark skies.

Sunday, February 5, 2023: Snow Moon

At 18:29 UTC today our natural satellite in space reaches its full phase. It will be best viewed at moonrise where you are tonight when it will appear on the eastern horizon in a blaze of orange.

Once it’s risen and darkness creeps up have a look close at Capella, the brightest star in the constellation Auriga, for comet C/2022 E3 (ZTF).

Constellation of the week: Cassiopeia

This constellation is located near the North Star and is visible throughout the year in the northern hemisphere. It is represented by a “W” shaped pattern of stars and is easily identifiable by its distinctive shape. Cassiopeia is named after the queen of Ethiopia in Greek mythology and is located in the direction opposite the Big Dipper, which is part of the constellation Ursa Major.

Object of the week: M52

An open cluster of stars in the northern part of the constellation of mCassipoei, M52 is about 5,000 light-years from Earth. It’s visible to the naked eye under dark-sky conditions as a small, diffuse patch of light, though it’s best observed through binoculars.

Times and dates given apply to mid-northern latitudes. For the most accurate location-specific information consult online planetariums like Stellarium and The Sky Live. Check planet-rise/planet-set, sunrise/sunset and moonrise/moonset times for where you are.

Wishing you clear skies and wide eyes.

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Regular old rock? Think again. Here’s your guide to erratic boulders in Alberta

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If you’re taking a walk just east of Calgary’s Coventry Hills neighbourhood, you may dismiss it as a regular old rock covered in graffiti.

But to Lincoln Friske, it’s a local treasure.

A large erratic boulder sits just past Nose Creek Park. Friske visits the massive rock on his daily dog walks, and he decided recently to create a digital 3D model of it so others could appreciate it, too.

“It’s set up just like an anomaly in the middle of this massive park,” he said in an interview on the Calgary Eyeopener. “Most people didn’t even know there was this graffiti erratic in our own backyard.”

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Erratics are stones, boulders or big blocks picked up and moved by glaciers from one place to another during the last ice age.

There are thousands dotting the Foothills, part of a 600-kilometre section known as the Foothills Erratics Train. It runs from about Hinton, Alta., all the way down to the Montana border.

Eva Enkelmann, an associate professor in the University of Calgary’s department of geoscience, says the boulders typically look out of place.

“It almost looks like it fell out of the sky. What that means is it doesn’t really match with the rocks you find in that area,” she said.

The stones are typically white, grey or slightly pink.

They’re made of quartzite — or cemented sand grains — dating back some 500 million years, according to Dale Leckie, geologist and author of The Scenic Geology of Alberta: A Roadside Touring And Hiking Guide.

This large boulder sits in Nose Hill Park, part of the Foothills Erratics Train. (Submitted by Dale Leckie)

Researchers have traced the material back to Mount Edith Cavell in Jasper National Park, about 300 kilometres northwest of Calgary.

“They are a very distinctive type of rock,” Leckie said.

“You can see features inside them, which geologists call cross-beds. They’re structures from the waves and the tides when they were deposited.”

So how did they get here?

About 20,000 years ago, a landslide occurred in Jasper National Park.

The tumbling boulders fell onto valley glaciers in the Athabasca River valley. They floated north, then east, then bumped into the Laurentide ice sheet, which covered most of Canada at the time, and were redirected southward, Leckie said.

Over time, they became scattered across the Foothills.

“When the ice melted, eventually it just let them down, I’ll say almost gently, onto the landscape, slipping, sliding back and forth,” Leckie said.

A map illustrates where the Foothills Erratics Train runs along the Rockies.
The Foothills Erratics Train runs from about Hinton, Alta., all the way down to the Montana border. (Government of Alberta)

Most of the erratic boulders landed in their current resting spots about 16,000 years ago.

Another distinctive feature is how solid the erratics are, Enkelmann said.

“Only rocks that are very, very hard actually survive such a long transport,” she said. “The river would usually round the boulders and eventually they turn into pebbles.”

If you look closely, though, some of the boulders do have some round edges along their lower portions.

That’s because hundreds of years ago, bison used to rub up on the boulders to get rid of their winter coats, Leckie said, creating more polished bits. They also created depressions around the boulders known as buffalo wallows.

Where are they?

You can stumble upon an erratic boulder in many farmers’ fields running along the Rocky Mountains, Leckie said, but some of the rocks have become famous landmarks.

The largest and most well-known example would be the Okotoks erratic — also known as Big Rock — which is about the size of a three-storey apartment building. A 3D model of the erratic is also available courtesy of the University of Calgary.

Blue signs describing the history of the rock sit on sidewalks, with the massive Okotoks erratic in the distance.
The Okotoks erratic is protected by the Government of Alberta for its geological and cultural importance. (Submitted by Dale Leckie)

The province designated Big Rock a provincial historic resource in 1978 to protect its geological and cultural importance.

“I think they’re so interesting because they’re just giant blocks,” Leckie said.

“They really grab your attention … they just jump out in the landscape because they’re standing high almost like sentinels.”

Several notable erratics are located in Calgary, including the one documented near Coventry Hills.

One sits on top of Nose Hill Park. Another, known as Split Rock, is in the city’s northeast, just off Harvest Hills Boulevard and Beddington Trail N.W.

A large rock split in half sits in a park.
Split rock can be found in Confluence Park in Calgary’s Beddington Heights neighbourhood. (Submitted by Dale Leckie)

Leckie has seen others in a McKenzie Lake playground and a Tuscany rest area. In Panorama Hills, there’s an erratic — sometimes referred to as crater rock — in a small park.

There are hundreds more, says Enkelmann, and once you’re aware of them, you’ll start to notice them everywhere.

“For me, it’s fascinating that you can weave this whole story by looking at these erratics here in the city, where we are relatively far away from the mountains but we have this evidence,” she said.

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