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Tue, 21 Aug 2018
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Comets

Fireball

Loud boom over North Carolina caused by meteor fireball

Meteor over NC
© American Meteor Society
The American Meteor Society received about 50 reports about a fireball seen over the Southeast late Thursday night. This map shows places that reported seeing the fireball.
The American Meteor Society received about 50 reports about a fireball seen over the Southeast late Thursday night.

AMS said the fireball was seen shortly after 10 p.m. in North Carolina, South Carolina, Alabama, Tennessee, Georgia, Virginia and Kentucky and Tennessee.

Because there was nothing other than the fireball reported in the area at the time of the boom, speculation is that the boom was likely a meteor breaking up in the atmosphere.

Click here to see the AMS report.

Comet 2

Bizarro comet challenging researchers

llustration of Echeclus
© Florida Space Institute at UCF
llustration of Echeclus.
Scientists pursue research through observation, experimentation and modeling. They strive for all of these pieces to fit together, but sometimes finding the unexpected is even more exciting. That's what happened to University of Central Florida's astrophysicist Gal Sarid, who studies comets, asteroids and planetary formation and earlier this year was part of a team that published a study focused on the comet 174P/Echeclus. It didn't behave the way the team was expecting.

"This is another clue that Echeclus is a bizarre solar system object," said University of South Florida physics research Professor Maria Womack, who leads the team.

Comets streak across the sky and as they get closer to the sun look like bright fuzz balls with extended luminous trails in their wake. However, comets are actually bulky spheres of mixed ice and rock, many of them also rich in other frozen volatile compounds, such as carbon monoxide, carbon dioxide, hydrogen cyanide and methanol.

Comets heat up as they get closer to the sun, losing their icy layers by sublimation and producing emission jets of water vapor, other gases and dust expelled from the comet nucleus, Sarid said. Once they move away from the sun, they cool off again. But some comets start showing emission activity while still very far from the sun, where heating is low.

Fireball 4

Possible fast moving meteor fireball sighted over South Australia

Meteor Over Adelaide
© Herald Sun, Australia
Meteor Shower Adorns Southern Lights Over Tasmania.
A bright "fast-moving" light with a green trail across the sky Friday night has captured the imaginations of at least a few locals who are this morning trying to get to the bottom of what it is they saw - or think they saw.

Advertiser.com.au has received and read a smattering of reports about the strange light, which one expert says could have been a meteor or space junk re-entering the earth's atmosphere.

A Reddit user reported seeing "what I can only guess was a meteor" pass over Henley Beach.

"Saw it from the city, fast moving bright light, green trail, bright flash."

Another Reddit user responded that the same phenomenon was witnessed by "a lot of people" on the Eyre Peninsula.

Salisbury East man Bradley Cousins said he was driving home from work in Tanunda around midnight when he looked up at the moon because it "looked strange".

Archaeology

Tree rings pinpoint eruption of Iceland's Katla volcano to half a century before human settlement

Katla volcano tree rings
An international group of researchers has dated a large volcanic eruption in Iceland to within a few months. The eruption, which is the oldest volcanic eruption to be precisely dated at high northern latitudes, occurred shortly before the first permanent human settlements were established, when parts of the now mostly treeless island were still covered with forest.

The team, which included volcanologists, climatologists, geographers and historians among others, used a combination of scientific and historical evidence to pinpoint the eruption date of the Katla volcano between late 822 CE and early 823 CE, decades before the earliest settlers arrived. Their results are reported in the journal Geology.

In a similar way to how fossils can be used to understand the development and evolution of life on Earth, different types of environmental evidence can be used to understand what the Earth's climate was like in the past and why. The 'fingerprints' contained in tree rings and ice cores help scientists to estimate past climatic conditions and extend our understanding of the interaction between humans and the environment hundreds and thousands of years back in time.

Fireball 2

Potential new meteor shower from Comet Borisov

Meteor Shower
© Scott MacNeill
Peter Jenniskens and Esko Lyytinen report that the dust trail of 700-year comet Borisov, who just passed perihelion in 2014, will be in the Earth's path on 2017 July 29 at 00:22 UT. Earth will pass only 0.0006 AU inside the comet's orbit at a time when the comet has just passed perihelion, both favorable circumstances for detecting meteors. Observers in South Africa will have a chance to see a glimpse of this new 1-2 hour duration meteor shower.

Fireball 4

Mystery solved: Wow! signal from 1977 was generated by a comet

Wow! Signal
© The Ohio State University Radio Observatory and the North American Astrophysical Observatory (NAAPO)
A team of researchers with the Center of Planetary Science (CPS) has finally solved the mystery of the "Wow!" signal from 1977. It was a comet, they report, one that that was unknown at the time of the signal discovery. Lead researcher Antonio Paris describes their theory and how the team proved it in a paper published in the Journal of the Washington Academy of Sciences.

Back in August of 1977, a team of astronomers studying radio transmissions from an observatory at Ohio State called the "Big Ear" recorded an unusual 72-second signal—it was so strong that team member Jerry Ehman scrawled "Wow!" next to the readout. Since that time, numerous scientists have searched for an explanation of the signal, but until now, no one could offer a valid argument. Possible sources such as asteroids, exo-planets, stars and even signals from Earth have all been ruled out. Some outside the science community even suggested that it was proof of aliens. It was noted that the frequency was transmitted at 1,420 MHz, though, which happens to be the same frequency as hydrogen.

Fireball

Possible meteorite impact in Jaipur, India

Possible Meteorite Impact
© TopYaps
The universe has its own peculiar ways to establish contact with the planet Earth. Although we have been quite lucky for the past hundreds of years that nothing as destructive as the extinction of dinosaurs has happened, however, every now and then, the cosmic bodies give us a visit in the form of meteorites.

Monday night turned into a nightmarish experience for the people of Mukundpura village when a mysterious object resembling a fireball fell on the farm of Banshi Bagha. Scared and skeptical of the object, people spent the night fearing an explosion. The area is situated on the outskirts of city of Jaipur.

Comet 2

New Comet: C/2017 K4 (ATLAS)

CBET nr. 4397, issued on 2017, June 01, announces the discovery of a comet (magnitude ~17) by the "Asteroid Terrestrial-impact Last Alert System" (ATLAS) Team on CCD exposures taken on May 26.5 with the ATLAS 0.5-m f/2.0 Schmidt telescope at Haleakala. The new comet has been designated C/2017 K4 (ATLAS).

I performed follow-up measurements of this object, while it was still on the neocp. Stacking of 10 unfiltered exposures, 120 seconds each, obtained remotely on 2017, May 29.4 from Q62 (iTelescope network) through 0.43-m f/6.8 reflector + CCD, shows that this object is a comet with a diffuse coma nearly 10 arcsec in diameter

My confirmation image (click on it for a bigger version)
C/2017 K4 (ATLAS)
© Remanzacco Blogspot

Fireball

Meteor fireball lights up southern English coast

A fireball brighter than the moon lit up the skies over Dawlish on Thursday night - and a video shows the spectacular ball of light plummeting down to earth.

An amazing video, shot by Dawlish Beach Cam, shows the fireball, otherwise known as a meteor, at 11.38pm. It is reported that over 50 members of the public reported seeing phenomenal light ball to the UK Meteor Network.

The operators of the Dawlish Beach Cam reported the sighting to the UK Meteor Network.

A spokesman from Dawlish Beach Cam said: "This particular type is known as a Bolide fireball which means that it is brighter than the moon.

"The team are still collating information on this particular event but they do have some other footage and the trajectory they believe the fireball took.

Fireball 4

Asteroids which could wipe out an entire continent are hidden by the Taurids meteor shower, astronomers claim

asteroid collision with Earth
The annual Taurids meteor shower is one of the highlights of the stargazing calendar. But the comet that causes this natural wonder could be hiding gigantic asteroids which are large enough to wipe out whole continents.

That's the warning from a team of academics at the Astronomical Institute of the Czech Academy of Science, who have been keeping a close eye on the Taurids.

Each year in late October and November, Earth's skies light up with shooting stars when the Earth passes through debris called the Taurids which is left behind by comet Encke.

However, the Czech astronomers claimed that asteroids called 2015 TX24 and 2005 UR are "direct members" of an undiscovered "branch" of the Taurids.