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New formation theory explains the mysterious interstellar object 'Oumuamua

'Oumuamua-like objects
© NAOC/Y. Zhang
This illustration shows the tidal disruption process that can give rise to 'Oumuamua-like objects.
Since its discovery in 2017, an air of mystery has surrounded the first known interstellar object to visit our solar system, an elongated, cigar-shaped body named 'Oumuamua (Hawaiian for "a messenger from afar arriving first").

How was it formed, and where did it come from? A new study published April 13 in Nature Astronomy offers a first comprehensive answer to these questions.

First author Yun Zhang at the National Astronomical Observatories of the Chinese Academy of Sciences and coauthor Douglas N. C. Lin at UC Santa Cruz, used computer simulations to show how objects like 'Oumuamua can form under the influence of tidal forces like those felt by Earth's oceans. Their formation theory explains all of 'Oumuamua's unusual characteristics.

"We showed that 'Oumuamua-like interstellar objects can be produced through extensive tidal fragmentation during close encounters of their parent bodies with their host stars, and then ejected into interstellar space," said Lin, professor emeritus of astronomy and astrophysics at UC Santa Cruz.

Comet 2

New Comet C/2020 F8 (SWAN)

CBET 4750 & 4752 & MPEC 2020-G94, issued on 2020, April 13, announce the discovery of a comet (total magnitude ~8.5) by M. Mattiazzo in the low-resolution public website hydrogen Lyman-alpha images obtained with the Solar Wind Anisotropies (SWAN) camera on the Solar and Heliospheric Observer (SOHO) spacecraft. The new comet has been designated C/2020 F8 (SWAN).

We performed follow-up measurements of this object while it was still on the PCCP webpage through the Telescope Live network.

Stacking of 3 unfiltered exposures, 30 seconds each, obtained remotely on 2020, April 11.4 from X02 (Telescope Live, Chile) through a 0.6-m f/6.5 astrograph + CCD, shows that this object is a comet with a compact coma about 5' in diameter and a tail 6' long in PA 220. Total magnitude 8.4.
Stacking of 3 unfiltered exposures, 120 seconds each, obtained remotely on 2020, April 11.7 from Q56 (Telescope Live, Australia) through a 0.1-m f/3.6 astrograph + CCD, shows that this object is a comet with a compact coma about 8' in diameter and a tail 25' long in PA 220.

Our confirmation images (click on it for a bigger version):

Comet C/2020 F8 Swan
© Remanzacco Blogspot

Comet 2

The Younger Dryas Impact - Armageddon at 10,000 BCE

Fragments of a comet likely hit Earth 12,800 years ago, and a little Paleolithic village in Syria might have suffered the impact.
The Paleolithic settlement of Abu Hureyra
© Jennifer Rice, CometResearchGroup Org
The Paleolithic settlement of Abu Hureyra, in what is now Syria, may have been destroyed by the airburst of an impacting comet about 12,800 years ago.
Abu Hureyra is an important archaeological site in Syria, known for artifacts documenting early adoption of agriculture in the region. It may also be recognized as the only known human settlement to have been hit by a fragment of a comet.

The site, now under the waters of Lake Assad, was quickly excavated between 1972 and 1973 before construction of the Tabqa Dam flooded the area. During the excavation, archaeologists realized that there were really two sites, one on top of the other. The first was a Paleolithic settlement of hunter-gatherers, and the second was a farming town, with new buildings of a different style.

A new analysis of samples of soil and artifacts salvaged from the original excavation has revealed a surprising finding: The Paleolithic village at Abu Hureyra was indirectly hit and destroyed by fragments of a comet that slammed into Earth about 12,800 years ago.

The researchers think that upon entering Earth's atmosphere, the already-fractured comet likely broke up into several more pieces, many of which didn't reach the ground. Instead, they produced a string of explosions in the atmosphere known as airbursts. Each airburst was as powerful as a nuclear blast, instantaneously vaporizing the soil and vegetation underneath and producing powerful shock waves that destroyed everything for tens of kilometers around. The village at Abu Hureyra was hit by one of these shock waves.

Comet 2

New Comet C/2020 F5 (MASTER)

CBET 4746 & MPEC 2020-G73, issued on 2020, April 08, announce the discovery of a comet (magnitude ~15.8) in images taken with the "Mobile Astronomical System of the Telescope-Robots" (MASTER) auto-detection system (0.40-m f/2.5 reflector) near San Juan, Argentina. Additional pre-discovery observations from Mar. 17.0 UT (mag 15.8-15.9), Mar. 22.0 (mag 15.8), and Mar. 23.0 (mag 15.7-15.8) were found on images taken with the MASTER 0.40-m reflector at the South African Astronomical Observatory (Sutherland). The new comet has been designated C/2020 F5 (MASTER).

We performed follow-up measurements of this object while it was still on the PCCP webpage.

Stacking of 22 unfiltered exposures, 60 seconds each, obtained remotely on 2020, April 05.7 from Q62 (iTelescope network) through a 0.43-m f/6.8 astrograph + CCD, shows that this object is a comet with a compact coma about 10" in diameter and a tail 30" long in PA 290.

Our confirmation image (click on it for a bigger version)
Comet C/2020 F5 MASTER
© Remnanzacco Blogspot

Attention

Shark kills Australian wildlife worker on Great Barrier Reef

Shark attacks
A shark fatally mauled a young Australian wildlife worker on the Great Barrier Reef, officials said Tuesday.

Queensland state Premier Annastacia Palaszczuk said the 23-year-old victim worked for the Queensland Parks and Wildlife Service.

"Once again a family out there is grieving for a young man who tragically has lost his life in this horrific shark attack," she told reporters.

Police said the man was in the water, returning to a vessel chartered by the service when he was attacked Monday near North West Island, 75 kilometers (47 miles) northeast of Gladstone. He suffered extensive injuries to his leg and arm and died at a hospital hours later.

Comet 2

New Comet C/2020 F3 (NEOWISE)

CBET 4740 & MPEC 2020-G05, issued on 2020, April 01, announce the discovery of a comet (magnitude ~17) in infrared images obtained with the Near-Earth Object Wide-field Infrared Survey Explorer (or NEOWISE; formerly the WISE earth-orbitingsatellite; cf. CBET 4225). The new comet has been designated C/2020 F3 (NEOWISE).

We performed follow-up measurements of this object while it was still on the PCCP webpage.

Stacking of 14 unfiltered exposures, 60 seconds each, obtained remotely on 2020, March 31.5 from Q62 (iTelescope network) through a 0.50-m f/6.8 astrograph + CCD + focal reducer, shows that this object is a comet with a diffuse coma about 1 arcmin in diameter and a tail 20" long in PA 115.

Our confirmation image (click on it for a bigger version)
Comet C/2020 F3 NEOWISE
© Remanzacco Blogspot

Comet 2

New Comet C/2020 F2 (ATLAS)

CBET 4739 & MPEC 2020-G04, issued on 2020, April 01, announce the discovery of a comet by R. Wainscoat on CCD images obtained on Mar. 22.6 UT with the Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala, which he then noticed (via posting at the Minor Planet Center's NEOCP webpage) was apparently identical with an apparently asteroidal object (magnitude ~19) discovered on CCD images taken the previous night with a 0.5-m f/2 Schmidt reflector at Haleakala, Hawaii, in the course of the "Asteroid Terrestrial-Impact Last Alert System" (ATLAS) search program. The new comet has been designated C/2020 F2 (ATLAS).

I performed follow-up measurements of this object while it was still on the PCCP webpage. Stacking of 15 unfiltered exposures, 120-sec each, obtained remotely, from Telescope Live (El Sauce, Chile) on 2020, March 25.3, through 0.6-m f/6.5 astrograph + CCD, shows that this object appears slightly diffuse compared to the nearby field stars of similar brightness.

My confirmation image (click on it for a bigger version)

Comet C/2020 F2 ATLAS
© Remanzacco Blogspot

Fireball 5

Scientists agree: Younger Dryas impact event wiped out ancient civilization

Meteor
© iStockphoto
The Earth was hit by a fragmented comet around 13,000 years ago at the end of the Pleistocene Era and scientists are now starting to agree.

A new research paper has been published in Scientific Reports regarding an ancient civilisation in what is modern-day Syria that was wiped out by the cataclysm, as academics finally come round to the idea that yes this event did happen.

Even the sceptic Michael Shermer, who famously debated Graham Hancock on the Joe Rogan podcast has tweeted Graham saying:

"Ok Graham, I shall adjust my priors in light of more research like this, and modify my credence about your theory."


Comet 2

Comet Y4 ATLAS brightening, could become naked-eye bright by spring

Comet ATLAS
© Michael Jäger (main) and Gianluca Masi
Comet ATLAS looked like a misty ball of light with a brighter core (nucleus) on March 11. Hints of a tail are visible in both photos.
Not since December 2018 when Comet 46P/Wirtanen passed near the Pleiades star cluster has a naked-eye comet graced the night sky. It reached 5th magnitude at the time and looked like a small wad of glowing fuzz from a dark sky site. Wirtanen never developed a bright tail, one of the most distinguishing and beautiful aspects of a comet. Since then plenty of comets have passed by, but only a few have been visible in binoculars and most have required a telescope.

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The Great Lake Tahoe comet tsunami

Lake Tahoe
© Epoque
One of the best things about the Younger Dryas Impact Hypothesis is finding catastrophic features that may date to the event, but have not yet been directly connected with it. Today I submit one of the finest examples: The Great Lake Tahoe Comet Tsunami.

Its is a well-published and uncontroversial fact that in the recent prehistoric past a gargantuan rock shelf on the western shore of Lake Tahoe collapsed. FIVE SQUARE MILES of rock and sediment slipped into the gin-clear waters of the deep alpine lake and vomited a 300′ high tsunami wave that raced across the lake in five minutes, crashed on the eastern shore, ran up a 1000 feet high, and retreated leaving scars on the landscape visible today. The oscillating "seiche waves," rocked back and forth and in and out of the lake for half an hour of lacustrine hell.

Lake Tahoe was a bad place on a bad day.

When was the bad day? As determined in the most recent detailed study by James Moore et al. (2014) link below, the youngest estimate for the catastrophic event is our favorite geological and cultural milestone of 12,000 years ago, and the outer limit is 21,000. This range is supported by two sets of data. The older limit is defined by dating a glacial moraine no older than 21,000 years, which was breached by the debris flow. (If it happened today, and was studied thousands of years in the future, it would also be constrained by this early date).