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Large ancient impact event discovered in Southeast Asia

Impact on Earth
© John R. Foster/Science SourceAn artist’s representation of a large impact on Earth.
A kilometer-size asteroid slammed into Earth about 800,000 years ago with so much force that it scattered debris across a 10th of our planet's surface. Yet its impact crater remains undiscovered. Now, glassy remains believed to have come from the strike suggest the asteroid hit southeast Asia as our close ancestors walked the Earth.

"This impact event is the youngest of this size during human evolution with likely worldwide effects," says Mario Trieloff, a geochemist at the University of Heidelberg in Germany not involved in the research. Large impacts can disrupt Earth's climate by spewing dirt and soot high into the atmosphere, where it can block sunlight for months or even years.

Putative remains from this impact have been found before. Researchers have recovered chunks of glassy debris known as tektites across Asia, Australia, and Antarctica, and their distribution pattern suggests the asteroid struck Southeast Asia: The largest tektites-weighing more than 20 kilograms and presumably ejected the shortest distances from the impact-have been found there.

Question

Mystery boom shakes Michigan village blamed on 'frost quake'

Michigan mystery boom
Most days, the Ionia County community of Pewamo is a about as peaceful as it gets. You may hear the rumble of the occasional semi-truck rolling through the village. Otherwise it's pretty quiet.

That was not the case about 4 p.m. New Year's Day.

"We just heard what sounded like an explosion ... It shook the entire house," Bethanie Kramer, who lives outside of the village. "It was not subtle at all. It was 'boom!'"

Kramer wasn't alone. Post after post on the "wassup IONIA?" Facebook page described reactions to the event from all over northeast Ionia County.

"Carson City, down to Westphalia, Lyons, Muir - they all heard it," Kramer said.

Ionia County 911 received four or five calls about the boom, but no reports of injuries or damage.

So far, there are no definitive answers as to what caused it. Speculation ranged from someone playing with dynamite to an earthquake to an attack by North Korea.

One possible explanation that seems to make the most sense has to do with the cold weather that has gripped West Michigan. The sound could have come from a phenomenon known as a frost quake.

Comment: This is what cryoseisms or frost quakes sound like, nothing like "an explosion ... It shook the entire house."

Given that meteor fireball activity is increasing dramatically, isn't it far more likely these folks are hearing overhead meteor explosions? See also:


Comet 2

Did comet impacts kill lots of animals in Alaska?

impact-related microspherules
© Hagstrum et. al/Scientific Reports
To laypeople, the "muck" found in certain areas of Alaska and Yukon is just dirt - dark, silty, often frozen, and full of plant material. To miners, it is somewhat of a nuisance. When dug out and left to thaw, the muck lets loose a fetid stench due to its high organic content. To scientists, however, the muck is a graveyard, and a fascinating one at that. Over the years, thousands of remains of bison, mammoth, horse, musk ox, moose, lynx, lion, mastodon, bear, caribou, and even camel have been uncovered.

More interesting than the mere presence of this zoological gold mine is the actual condition of the remains. Cached inside the frozen mucks for as long as 48,000 years, the remains are remarkably well preserved, with some carcasses mostly intact and effectively mummified. Even more curious, many animals show no signs of predation, scavenging, or decomposition, and despite disarticulated bones, seemed to be in relatively good health at the time of their demise.

This made Jonathan Hagstrum, a research geophysicist at the U.S. Geological Survey, wonder... What killed all of these animals? He and colleagues Richard Firestone, Allen West, James Weaver, and Ted Bunch share an intriguing hypothesis.

They think the seemingly sudden deaths of many of these animals in the Alaskan and Yukon mucks could be explained by airbursts and impacts from comet debris that struck Earth during the Late Pleistocene, between 11,000 and 46,000 years ago. Hagstrum and his colleagues recently presented new evidence for this idea in the journal Scientific Reports.

Fireball 4

Dazzling green meteor fireball seen flying above Peterborough, UK

A photo of the meteor taken by E.Ground which was tweeted to the Peterborough Telegraph
A photo of the meteor taken by E.Ground which was tweeted to the Peterborough Telegraph
It is normally fireworks which light up the sky on New Year's Eve, but incredibly the last few hours of 2017 were graced by a dazzling green meteor which passed through the sky above Peterborough.

The green fireball was spotted in and around the city, with many of you taking to social media in an excited state to share the discovery.

One of the people to spot the meteor was our own photographer David Lowndes who tweeted: "Reports of a very bright meteorite with long tail over sky near Sawtry at 5.30 today. Anyone see it?"

Many people then responded to the tweet to say they had seen the meteor, including Lou whose friend E.Ground had managed to snap a picture of it near Guyhirn.


Fireball 5

Meteor fireball lights up night sky over New England

The webcam at Mount Agamenticus in southern Maine captured an image of a fireball as it streaked across the sky just before 6 p.m. Tuesday.
© www.agamenticus.orgThe webcam at Mount Agamenticus in southern Maine captured an image of a fireball as it streaked across the sky just before 6 p.m. Tuesday.
People in New Hampshire and other parts of New England and the Northeast were treated to an unexpected light show early Tuesday night when a bright fireball that appeared to be a meteor shot across the night sky.

Many reported seeing the fireball just before 6 p.m.

Greg Kretschmar, host of WHEB's "Greg & the Morning Buzz" radio show, was one of those lucky enough to catch the sight as he was driving north on Route 16 in Newington.

Kretschmar said it streaked along the side of him from south to north and he saw what appeared to be "sparks" in the tail with a hint of green. He said the fireball lasted about four or five seconds.


Fireball

Meteor fireball explodes over Crimea

Meteorite
© an-crimea.ru
A powerful explosion occurred in the sky over the city of Simferopol, the Crimea, on December 26. The origin of the explosion remains unknown; EMERCOM officials are trying to look into circumstances.

Local residents have posted a few photos taken in first minutes after the explosion. The photos depict a white trail in the sky, which usually remains behind a flying plane, but it is not straight.

Some people assumed that the explosion could be related to fighter aircraft and their aerobatic stunts.

Fireball 2

Slow-moving meteor fireball filmed over Spain

fireball
© NASA stock image
This beautiful meteor, which resembles a Christmas star, was spotted over Spain on Dec. 23, at 22:07 local time (21:07 universal time). It was produced by a fragment from a comet that hit the atmosphere at about 43000 km/h. The meteor overflew the Mediterranean Sea.

It began at a height of around 93 km, and ended at an altitude of about 60 km over the sea.

It was recorded in the framework of the SMART Project (University of Huelva) from the astronomical observatories of Calar Alto (Almería), Sierra Nevada (Granada), La Sagra (Granada), La Hita (Toledo) and Sevilla.


Fireball 2

Meteor fireball flashes across Finnish skies; more than 200 sightings

fireball path
Fireball path
An especially bright meteor streaked through the sky at around 8 pm on Friday evening. The Ursa Astronomical Association has logged more than 230 sightings of the southbound fireball.

The phenomenon is known as a bolide, an extremely bright meteor that usually explodes in Earth's atmosphere.

A local Oulu man, Markku Paaso, managed to hastily record the atmospheric ball of light with his car dashboard video camera as the bolide fell in its horizontal trajectory.

"It was like a slow-moving, super-bright shooting star," one Yle reader recounts in their sighting.


Friday's bolide is the second bright aerial anomaly logged in Finland this winter. In November a rare fireball was sighted in Lapland that caused a stir in the skywatching community for its fierce brightness. The undestroyed refuse from that earlier meteorite fell to the Earth in Northern Lapland, where it still remains.


Fireball 3

Meteor fireball with sonic boom reported over Townsville, Queensland

Queensland meteor fireball
© Mt Stromlo ObservatoryAn image captured by the Mt Stromlo Observatory on Friday night.
Residents of the Australian city of Townsville, Queensland have reported seeing a meteor overnight according to the Daily Telegraph.

One resident Melissa Kruse described a brilliant flash in the sky.
"It was a matter of seconds from first sight to it falling out of sight.

"It was pretty spectacular. There was only one."
Ms Kruse added that it looked similar to the Chelyabinsk meteor which flew over Russia in 2013.

The Townsville phenomenon was witnessed by numerous other people who described seeing a "massive light over The Strand".

The Canberra Times stated that cameras at Mt Stromlo Observatory did capture a somewhat blurry picture of the fragment emitting a bright blue-green light.

It left a blue-green light trail behind it and travelled about 80,000 to 120,000 kilometres per hour, creating a sonic boom that was heard and felt by people below.

Fireball 2

Bright meteor fireball explodes over southern Norway

Norwegian meteor fireball
© IMO/Tore MyrhenNorwegian meteor fireball on December 18, 2017
On December 18, 2017, at 16:37:07 UT, a bright meteor fireball lit up the southern regions of Norway. The event was registered by cameras of the Norwegian Meteor Network on a partially cloudy sky.

A video of the event was recorded by Tore Myhren from Lillehammer, and shows the fireball through some clouds near the horizon.

"The meteor was of sporadic origin, with a radiant located at R.A. = 331,3°, Dec. = 62,2°," writes Kai Gaarder of the Norwegian Meteor Network, as reported by the International Meteor Organization.

Some eyewitness reports describing the phenomena include:

Ørjan Solheim:
"Saw an insane powerful flash of light in Rosendal. The whole valley and the mountains lighted up. A lot of times stronger than lightning. Lasted longer and was smoother than lightning. Stopped the car and went out, but could hear no sound."