100 full moons: Blazing fireball lights up Arctic sky

In this March 17, 2013 file photo, the Aurora Borealis bright up the sky at twilight between the towns of Are and Ostersund, Sweden. AFP PHOTO/JONATHAN NACKSTRAND
Updated 18 November 2017
0

100 full moons: Blazing fireball lights up Arctic sky

COPENHAGEN, Denmark: A blazing fireball lit up the dark skies of Arctic Finland for five seconds, giving off what scientists said was “the glow of 100 full moons” and igniting hurried attempts to find the reported meteorite.
Finnish experts were scrambling to calculate its trajectory and find where it landed, according to Tomas Kohout of the University of Helsinki’s physics department, who said Thursday night’s fireball “seems to have been one of the brightest ones.”
It produced a blast wave that felt like an explosion about 6:40 p.m. and could also be seen in northern Norway and in Russia’s Kola peninsula, he told The Associated Press on Saturday.
It might have weighed about 100 kilograms (220 pounds), according to Nikolai Kruglikov of Yekaterinburg’s Urals Federal University.
“We believe it didn’t disintegrate but reached a remote corner of Finland,” Kohout said, adding that any search plans for the meteorite must face the fact that “right now we don’t have much daylight” — four hours, to be precise.
The Norwegian meteorite network said the fireball “had the glow of 100 full moons” and likely was going northeast, perhaps “to the Norwegian peninsula of Varanger,” north of where the borders of Russia, Finland and Norway meet.
Kohout said scientists looked forward to any space debris they can get their hands on.
“We are happy to recover (it) since this is a unique opportunity to get otherwise inaccessible space material,” said Kohout. “This is why it’s worth it to search for them.”
Viktor Troshenkov of the Russian Academy of Sciences told the Tass news agency that the fireball could be part of a prolific meteor shower known as the Leonids, which peaks at this time of year. He said he felt Thursday’s fireball likely wasn’t the sole meteorite but others maybe were not seen due to thick clouds elsewhere.
Troshenkov told Tass that meteor showers can be even stronger. The Leonids reach their maximum once every 33 years — and the last time that happened was in 1998, he said. Amateur astronomers in the Arctic then saw about 1,000 meteors, 40 meteorites and one fireball in just one night.
In 2013, a meteorite streaked across the Russian sky and exploded over the Ural Mountains with the power of an atomic bomb, its sonic blasts shattering countless windows and injuring about 1,100 people. Many were cut by flying glass as they flocked to windows, curious about what had produced such a blinding flash of light.
The 2013 Chelyabinsk meteorite was estimated to be about 10 tons when it entered the Earth’s atmosphere at a hypersonic speed of at least 54,000 kph (33,000 mph). It shattered into pieces about 30-50 kilometers (18-32 miles) above the ground but some meteorite chunks were found in a Russian lake.
A meteoroid is smaller than a kilometer (0.62 mile), and often so small that when it enters the Earth’s atmosphere it vaporizes and never reaches the ground. A meteor is a flash of light caused by a meteoroid that fails to get through the Earth’s atmosphere. If part of it does survive, that’s called a meteorite.
Asteroids are generally larger chunks of rock that come from the asteroid belt located between the orbits of Mars and Jupiter.


Scientists amazed as Canadian permafrost thaws 70 years early

General view of a landscape of partially thawed Arctic permafrost near Mould Bay, Canada, in this handout photo released June 18, 2019. (Reuters)
Updated 19 June 2019
0

Scientists amazed as Canadian permafrost thaws 70 years early

  • “This premature thawing is another clear signal that we must decarbonize our economies, and immediately”

LONDON: Permafrost at outposts in the Canadian Arctic is thawing 70 years earlier than predicted, an expedition has discovered, in the latest sign that the global climate crisis is accelerating even faster than scientists had feared.
A team from the University of Alaska Fairbanks said they were astounded by how quickly a succession of unusually hot summers had destabilized the upper layers of giant subterranean ice blocks that had been frozen solid for millennia.
“What we saw was amazing,” Vladimir E. Romanovsky, a professor of geophysics at the university, told Reuters by telephone. “It’s an indication that the climate is now warmer than at any time in the last 5,000 or more years.”
With governments meeting in Bonn this week to try to ratchet up ambitions in United Nations climate negotiations, the team’s findings, published on June 10 in Geophysical Research Letters, offered a further sign of a growing climate emergency.
The paper was based on data Romanovsky and his colleagues had been analizing since their last expedition to the area in 2016. The team used a modified propeller plane to visit exceptionally remote sites, including an abandoned Cold War-era radar base more than 300 km from the nearest human settlement.
Diving through a lucky break in the clouds, Romanovsky and his colleagues said they were confronted with a landscape that was unrecognizable from the pristine Arctic terrain they had encountered during initial visits a decade or so earlier.
The vista had dissolved into an undulating sea of hummocks — waist-high depressions and ponds known as thermokarst. Vegetation, once sparse, had begun to flourish in the shelter provided from the constant wind.
Torn between professional excitement and foreboding, Romanovsky said the scene had reminded him of the aftermath of a bombardment.
“It’s a canary in the coalmine,” said Louise Farquharson, a post-doctoral researcher and co-author of the study. “It’s very likely that this phenomenon is affecting a much more extensive region and that’s what we’re going to look at next.”
Scientists are concerned about the stability of permafrost because of the risk that rapid thawing could release vast quantities of heat-trapping gases, unleashing a feedback loop that would in turn fuel even faster temperature rises.
Even if current commitments to cut emissions under the 2015 Paris Agreement are implemented, the world is still far from averting the risk that these kinds of feedback loops will trigger runaway warming, according to models used by the UN-backed Intergovernmental Panel on Climate Change.
With scientists warning that sharply higher temperatures would devastate the global south and threaten the viability of industrial civilization in the northern hemisphere, campaigners said the new paper reinforced the imperative to cut emissions.
“Thawing permafrost is one of the tipping points for climate breakdown and it’s happening before our very eyes,” said Jennifer Morgan, Executive Director of Greenpeace International. “This premature thawing is another clear signal that we must decarbonize our economies, and immediately.”