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Sat, 24 Oct 2020
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Comets

Fireball

Bright meteor fireball streaks over Edmonton, Canada

Rain wasn't the only thing falling in our city this evening, social media was flooded with reports of a sighting of what appears to be a meteor over Edmonton.
Blazing Meteor
© Pete Saloutos

Comment: More views from social media:



The American Meteor Society (AMS) received 106 reports about the meteor fireball, which was seen over Alberta, MT and Saskatchewan on Sunday, September 1st 2019 around 04:28 UT.

"This fireball would have been seen for 600km from either side of it, probably," said Mike Hankey, operations manager for the American Meteor Society, who speculated that the object was likely a bolide, a very bright meteor, based on the reports he has received.

The meteor spectrum ranges from meteor, to fireball, to bolide and super bolide, which is brighter than the Moon and almost as bright as the Sun.


Comet 2

Dr. Napier fingers fragmented comet in Younger Dryas and Bronze Age impacts

Comet 332P Fragmenting
© NASA, ESA, D. Jewitt (UCLA)
This image, captured on January 27 2016 by the Hubble Space Telescope, is one of three showing Comet 332P fragmenting as it nears the sun.
Folks, I am sorry to have been so scarce in recent months. Among other excuses for the inexcusable, the auto-mailer for subscribers to the site went down, and I felt I needed to repair it before posting. Fixing it turned into a mess which led to my continued procrastination. Much has happened in recent months in our subject though, and I look forward to catching up and posting more, as the year closes out.

First up is a fabulous new paper from Tusk friend and Scottish astronomer William Napier. Bill is a member of the Comet Research Group and contributes his world class knowledge on the behavior of comets in support of the Younger Dryas Impact Hypothesis. In this contribution he further refines the culprit in our favorite cataclysm, a fragmenting comet. But keep in mind, as sometimes others have not, that the subject comet is fragmenting IN SPACE over thousands of years, not in the earth's atmosphere. See The Bos misdirecting the nature and context of the fragmentation events here and here, and the CRG response here.

Meteor

It's called Apophis. It's 390m wide. And it could hit Earth in 31 years time

apophis asteroid
In Egyptian myth, Apophis was the ancient spirit of evil and destruction, a demon that was determined to plunge the world into eternal darkness.

A fitting name, astronomers reasoned, for a menace now hurtling towards Earth from outerspace. Scientists are monitoring the progress of a 390-metre wide asteroid discovered last year that is potentially on a collision course with the planet, and are imploring governments to decide on a strategy for dealing with it.

Nasa has estimated that an impact from Apophis, which has an outside chance of hitting the Earth in 2036, would release more than 100,000 times the energy released in the nuclear blast over Hiroshima. Thousands of square kilometres would be directly affected by the blast but the whole of the Earth would see the effects of the dust released into the atmosphere.

Comment: 15 years later, they're still reporting about Apophis as if it's breaking news.

As we said at the time...

sott.net meteor fireballs



Info

Lascaux Shaft Scene and cometary impacts

The Lascaux shaft scene is perhaps the most iconic of all European Palaeolithic cave artworks (see below). It shows a bison and human, apparently both dying and normally interpreted as a hunting scene. But we now know, beyond any reasonable doubt, the animal symbols represent constellations, and the Shaft Scene in particular very likely represents a date using precession of the equinoxes.
Lascaux Shaft Scene
© Copy of the Lascaux Shaft Scene, courtesy of Alistair Coombs
Using the zodiacal method and our ancient zodiac, the date 'written' in the scene is between 15,300 and 15,000 BC (see Prehistory Decoded). The similarity of this scene to Pillar 43 at Gobekli Tepe suggests it documents another asteroid or comet strike, this time from the direction of Capricornus (represented by the aurochs). It so happens that the Taurid meteor stream would rave radiated from this direction at this time, suggesting this artwork memorialises another strike from the Taurid system. Given the presence of a giant comet in the inner solar system at this time, such frequent impacts are entirely expected.

Very interestingly, this time span also corresponds to a sudden temperature fluctuation in the North Atlantic region (see Prehistory Decoded), documented by a Greenland ice core, and to a major cultural transition: the Magdalenian to Azillian.

Fireball 5

Perseids meteor shower to peak Monday night with stunning FIREBALL displays

Perseids meteor shower
© NASA/Ron Garan (@Astro_Ron)
Perseid meteor shower as seen from the International Space Station
It's that time of year again, when the spectacular Perseid meteor shower rains fire across the night sky. The days-long fireball fiesta is expected to peak this evening with an estimated 80 shooting stars per hour at its height.

Widely seen as one of the most entertaining celestial events of the year, the Perseids meteor shower is caused by meteoroids from the debris trail of the Comet 109P/Swift-Tuttle which orbits the sun once every 133 years.

Those in the Northern Hemisphere will be treated to the best views, provided they can escape the light pollution from towns and cities. The moon will frustrate proceedings somewhat as a full moon is due on Thursday, meaning the sky will likely be washed out for the majority of viewers, but fear not, as the Perseids have an ace up their sleeve.

Instead of shooting stars, stargazers can hunt for bright 'fireballs' which can last up to a second rather than merely fractions of a second like their shooting star brethren.

"...[T]he Perseids are rich in bright meteors and fireballs, so it will still be worth going out in the early morning to catch some of nature's fireworks," NASA says.

Fireball 4

'I thought it was Armageddon' - Perth residents stunned by early morning meteor fireball

Early risers around the Perth metropolitan area were stunned by a bright green light filling the night sky on Wednesday morning, but what looked like Armageddon was most likely a meteor, according to a Perth Observatory staffer.
Meteor Fireball
© Brisbane Times
Just before 6am 6PR News director Lisa Barnes was out for her morning run near Ellenbrook when she saw the phenomenon light up the sky.

"It was so amazing to see, it lit up the whole sky, a quick flash of light and then it drew my eyes to where I was heading (...) and then it was like a ball of light and I watched it fall."

Mrs Barnes said it was much bigger and brighter than a shooting star.

Comet 2

Spectacular Delta Aquariids meteor shower set to light up skies tonight

Meteor shower
© National Park Service
An annual meteor shower is set to peak tonight in a stunning night sky display that could see up to 20 flaming by per hour. Here's everything you need to know to catch the spectacular celestial show.

What?

The Delta Aquariids meteor shower is a spectacular display of what is essentially space dust and bits of debris from a comet (or comets) in our orbital path that flew close to the Sun.

The comet sheds particles that then smash into our atmosphere - around 60 miles above Earth - and zoom across our skies at about 90,000mph (150,000kph), at times vaporizing into shooting stars and leaving a trail of blazing light behind.

Comet 2

Impact hazard from disintegrating comets

Comet 73P
© NASA/JPL-Caltech/W.Reach [SSC/Caltech]
Last month, Bill Napier (co-creator of the coherent catastrophism theory, with Victor Clube) published his latest paper (MNRAS, vol. 488, p 1822-1827) on the impact hazard from disintegrating comets in the inner solar system. His focus is on a large 100 km comet in an Encke-like orbit. It is a sophisticated work that extends his earlier estimates, this time by combining explicit orbital simulations with a calibrated model of comet fragmentation (published by de Sisto et al. in 2009).

His aim, like mine in Prehistory Decoded, is to estimate the hazard to Earth from the kind of comet thought to have become trapped in our inner system a few tens of thousands of years ago. We know, pretty much, that this happened because of the massive zodiacal dust cloud and correlated fragments that remain in orbit.

He concludes that we can expect one or two impact collisions over the last 20,000 years, or so, with energy over 6000 Mt, and that this energy will likely be unevenly distributed across a hemispherical region. This is roughly 600 times the energy of the Tunguska impact, which itself was large enough to demolish one of our biggest modern-day cities (like Greater London).

This broadly supports my own estimates in Prehistory Decoded, based on simple fragmentation pathways and Opik's collision formula, where I find that we can expect one or two collisions with an energy of at least 10,000 Mt, and perhaps another ten with energy over 1,000 Mt, from the same sized comet over the same timescale. Great!

Fireball 5

Suspected meteorite crashes into rice field in India

Suspected Meteorite
© STR/AFP/Getty Images
The object was spotted ‘coming down from the sky’ and then excavated from a 150cm-deep hole by residents of Mahadeva village.
Madhubani/Patna: Farmers working in a paddy field at a village in Madhubani district were left shaken when a meteorite-like object weighing around 15kg fell from the sky, leaving a crater at the spot where it crashed.

Madhubani DM Shirsat Kapil Ashok told TOI that the incident took place around 2.30pm on Monday. "Agriculture labourers working the paddy field where the meteorite struck claimed that they saw a fireball-like object coming down from the sky and made a deep crater where it hit the ground. The farmers also saw smoke coming out from the spot in the water-filled agriculture field," Shirsat said.

Displaying the 'meteorite' wrapped in a red cloth on Tuesday morning, the Madhubani DM said the stone-like object has magnetic properties. He added that the mysterious object was kept secure in the treasury office at the Madhubani collectorate.

"I have written a letter to the principal secretary of the science and technology department along with a copy to the principal secretary of state art, culture and youth affairs department," Shirsat said, adding the sample was sent to Patna on Tuesday evening.

"The science and technology department will take a decision regarding further action. The object might be sent to space research organisations like ISRO or any museum," Shirsat said.

Fireball

Meteor fireball streaks across Australian skies

Fireball over Australia
© Screenshot YouTube
A screenshot from a YouTube video that is reportedly of the meteor that flew across the South East sky on the night of July 5.
Social media is buzzing with reports of a meteor spotted over the South Coast on Friday night.

On the Facebook group Australian Meteor Reports, administrator David Finlay said the meteor was spotted about 9pm on July 5 and believed it had come to ground somewhere in Victoria.

"I have reports of sonics from Forest Hill (Melbourne) to Mallacoota Vic. That's a distance of 400km. I've never heard of sonics being reported so far apart," he said in a Facebook post to the group.

He said sightings had been reported from as far north as Sydney and Orange.

"From these reports, and as long as this object was over land and not the ocean, I'm already predicting there are now meteorites on the ground somewhere in Victoria from this fall," he said.