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Wed, 14 Apr 2021
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Fireballs


Comet 2

Ancient impactor that created the Moon may still be inside Earth

Theia
© Jurik Peter/Shutterstock
Researchers are fairly certain that we gained our favorite satellite, the Moon, after a planet, Theia, collided with the proto-Earth 4.5 billion years ago. What's not certain are the details surrounding Theia's fate. Was it a hit-and-run, or did the mantles of the two planets merge?

Qian Yuan, Earth scientist at Arizona State University, and his colleagues recently suggested a new line of evidence to support the latter hypothesis, suggesting that Theia not only merged with Earth, but we might know right where the remnants of its mantle reside in Earth.

Giant impact hypothesis

"Compared to the Moon, there is much less [known] about Theia," says Yuan. "The Moon is there. You have samples. People have been there ... few people care too much about the impactor."

A lot of the work around the giant impact hypothesis involves comparing isotopes found on the Moon with those found on Earth. Their similarities in composition suggest that the Moon is made of a hunk of ancient Earth, meaning something like a giant impact knocked it off our Pale Blue Dot.

Original models estimated that the impactor, Theia, was about the size of Mars (half the size of Earth today). Though, some recent studies suggest it might've been more like four times the size of Mars, or roughly the size of the proto-Earth. Either way, most researchers agree that the core — the densest part — of Theia merged with the core of Earth incredibly quickly after the impact, in a matter of hours.

Fireball 2

Impact event in Antarctica 430,000 years ago discovered

Impact on Antarctica
© Mark A. Garlick
Mocked up illustration of touchdown impact on Antarctica by Mark A. Garlick.
A research team of international space scientists, led by Dr Matthias van Ginneken from the School of Physical Sciences' Centre for Astronomy and Planetary Science, has found new evidence of a low-altitude meteoritic touchdown event reaching the Antarctic ice sheet 430,000 years ago.

Extra-terrestrial particles (condensation spherules) recovered on the summit of Walnumfjellet (WN) within the Sør Rondane Mountains, Queen Maud Land, East Antarctica, indicate an unusual touchdown event where a jet of melted and vaporised meteoritic material resulting from the atmospheric entry of an asteroid at least 100 m in size reached the surface at high velocity.

This type of explosion caused by a single-asteroid impact is described as intermediate, as it is larger than an airburst, but smaller than an impact cratering event.

The chondritic bulk major, trace element chemistry and high nickel content of the debris demonstrate the extra-terrestrial nature of the recovered particles. Their unique oxygen isotopic signatures indicate that they interacted with oxygen derived from the Antarctic ice sheet during their formation in the impact plume.

The findings indicate an impact much more hazardous that the Tunguska and Chelyabinsk events over Russia in 1908 and 2013, respectively.

This research, published by Science Advances, guides an important discovery for the geological record where evidence of such events is scarce. This is primarily due to the difficulty in identifying and characterising impact particles.

Fireball

'What Is That In The Sky?' Floridians catch meteor fireball's close brush with Earth

Residents captured the asteroid streaking through the sky on Monday night
It wasn't a bird or a plane that gave Floridians a shock late Monday night.

It wasn't even Superman.

A meteor shot across the sky around 10 p.m. Monday.

On social media, residents along the state's Atlantic coast, from West Palm Beach south to Miami, shared videos on Twitter of the surprising sight.

Dashcam footage and security videos showed a still, dark night suddenly lit up by what appeared to be a large fireball streaking diagonally across the sky. In just a few seconds, it was over.


Fireball 4

Bright meteor fireball turns the Central Asian night sky green

fireball
The fall of the celestial object, probably a meteorite, was observed in several countries in the region, including Kyrgyzstan and Uzbekistan.

On Tuesday, residents of the Chui and Bishkek region in Kyrgyzstan, a nation located in Central Asia, were surprised by a bright flash that illuminated the night sky intensely as it fell towards Earth. The phenomenon, presumably caused by a meteorite, is already being investigated by the corresponding authorities, local media report .

In the videos of the event, a bright white object can be observed falling towards our planet and illuminate, at least for a few moments, the clouds in the night sky with an intense light green color, before continuing its journey towards the earth's surface.


Comet 2

New Comet C/2019 U5 (PANSTARRS)

CBET 4953 & MPEC 2021-G80, issued on 2021, April 07, announce that an apparently asteroidal object (magnitude ~21.0) discovered on CCD images obtained with the F51 Pan-STARRS 1 survey's 1.8m Ritchey-Chretien on 2019, October 22.22 and designated A/2019 U5 (cf. MPEC 2019-V10) has been found to show cometary appearance by other CCD observers over the past half year. The new comet has been designated C/2019 U5 (PANSTARRS).

Stacking of 20 unfiltered exposures, 120 seconds each, obtained remotely on 2021, April 02.1 from Z08 (Telescope Live, Oria) through a 0.7 m f/8 Ritchey Chretien + CCD, shows that this object is a comet with a compact coma about 15" arcsec in diameter (Observers E. Guido, M. Rocchetto, E. Bryssinck, M. Fulle, G. Milani, C. Nassef, G. Savini, A. Valvasori).

Our confirmation image (click on it for a bigger version; made with TYCHO software by D. Parrott)

Comet C/2019 U5 (PANSTARRS)
© Remanzacco Blogspot

Fireball 2

Meteor fireball observed over Scotland

Meteor fireball
© Alamy (STOCK IMAGE)
Many Scots saw the meteor in the sky
A HUGE meteor lit up the skies of Scotland tonight.

Weatherman Sean Batty told fans he spotted a "fireball dropping out of the sky".

The STV weather presenter took to social media to ask other Scots whether they had seen the very bright meteor.

He said: "Oh wow, did anyone else just spot that fireball dropping out of the sky there? Very bright meteor by the looks of it!"

It is understood to have come crashing through the atmosphere around 8.30pm tonight.

Sightings were reported from all over the country including in Fife and Inverclyde.

Many Scots took to Twitter to report similar sightings of the firework-like flash.

Fireball 2

Meteor fireball over Sevilla and Cádiz, Spain (4 April)

fireball
This bolide was spotted over Spain on 4 Abril 2021, at about 23:42 local time (equivalent to 21:42 universal time). The event was generated by a rock from an asteroid that hit the atmosphere at about 57,000 km/h. The fireball began at an altitude of about 81 km over the south of the province of Sevilla, and ended at a height of around 30 km over the north of the province of Cádiz.

This bright meteor was recorded in the framework of the SMART project, operated by the Southwestern Europe Meteor Network (SWEMN) from the meteor-observing stations located at Sevilla, La Hita (Toledo), La Sagra (Granada), and Madrid (Universidad Complutense). The event has been analyzed by the principal investigator of the SMART project: Dr. Jose M. Madiedo, from the Institute of Astrophysics of Andalusia (IAA-CSIC).


Fireball 2

Meteor fireball over Toledo, Spain (April 1)

fireball
On 1 April 2021, at about 23:05 h local time, a very bright fireball was spotted over Spain. This bolide was generated by a rock from an asteroid that hit the atmosphere at about 72,000 km/h. The fireball, that could be seen over the whole Iberian Peninsula because of its high brighness, overflew the province of Toledo. It began over that province at an altitude of about 92 km, and ended at a height of around 43 km.

This bright meteor was recorded in the framework of the SMART project, operated by the Southwestern Europe Meteor Network (SWEMN), from the meteor-observing stations located at Sevilla, La Hita (Toledo), La Sagra (Granada), Calar Alto (Almería), and Madrid (Jaime Izquierdo, Complutense University of Madrid). The event has been analyzed by the principal investigator of the SMART project: Dr. Jose M. Madiedo, from the Institute of Astrophysics of Andalusia (IAA-CSIC).


Fireball 2

Fireball spotted over Oshkosh, Wisconsin

A fireball is seen on our Oshkosh Skycam. March 29, 2021
© WBAY
A fireball is seen on our Oshkosh Skycam. March 29, 2021
Action 2 News This Morning viewers spotted a possible meteor live on air Monday.

The fireball shot across the sky as we put up our Oshkosh Skycam.

The fireball comes from the right of the screen. It's faint, so you'll have to watch closely. The video is located above.

The American Meteorological Society meteor website shows multiple fireball reports in the United States Monday morning. Someone spotted it in North Fond du Lac. Did you see one? Click here to enter the report.

(View video here)

Fireball 5

Bright meteor fireball blazes over Denmark

Event 1950-2021 observers map
© AMS (screen capture)
Event 1950-2021 observers map
The American Meteor Society (AMS) received 100 reports (event 1950-2021) about a meteor fireball seen over Brandenburg, Drenthe, Mecklenburg-Vorpommern, Nordrhein-Westfalen, Schleswig-Holstein, Västra Götalands län and Zuid-Holland on Saturday, March 27th 2021 around 19:54 UT.