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Mon, 13 Jul 2020
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Fireball 5

Impact of meteorites led to life-giving amino acids on Earth

Meteorite Impact
© Provided byTohoku University associate professor Yoshihiro Furukawa
An illustration of how a meteorite struck Earth 4 billion years ago.
A simulation of how substances essential for living creatures were formed on Earth reinforces the theory that life started after meteorites rained down on the planet.

Living organisms are said to have emerged on Earth 4 billion years ago. A large number of meteorites are believed to have bombarded the planet 200 million years before and after the birth of life.

"Materials needed for the start of life may have been generated over long periods, offering a chance for life to appear," said Yoshihiro Furukawa, an associate professor of geochemistry at Tohoku University.

Furukawa and his colleagues primarily from the university put carbon dioxide, nitrogen, water and iron in a container to reproduce conditions of primordial times. The vessel was then struck with a piece of metal to simulate the impact from a meteorite.

Fireball 2

Newly detected chi Phoenicids meteor shower

The ongoing night-time video surveillance of the night sky called "CAMS" has discovered a meteor shower caused by yet another unknown long-period comet that passed close to Earth's orbit in a past return. SETI Institute meteor astronomer Peter Jenniskens reports that this shower was briefly seen on June 10 by southern hemisphere networks of the CAMS project in New Zealand, Namibia and Chile (see the map for June 10 at this project website.
New Meteor Shower
The meteoroid stream is unusual in that its orbit is nearly exactly perpendicular to the plane of the planets, having an inclination of 90.2 +/- 1.0 degrees. The shower has received the name "chi Phoenicids" and has been added as number 1036 to the list of meteor shower names maintained by the International Astronomical Union. A telegram announcing the discovery (CBET 4798) was issued today.

Fireball 2

Krakatoa And The Great Comet of 1882: Exploring The Real Engine of 'Climate Change'

Eruption of Perbuatan volcano on Krakatoa Island, 26 August 1883.
© Dea Picture Library/De Agostini/Getty Images
Eruption of Perbuatan volcano on Krakatoa Island, 26 August 1883.
In May 1883, the captain aboard the German ship Elizabeth observed ash spewing above Krakatoa, an island in the Sunda Strait between Java and Sumatra in Indonesia. In the following weeks, other vessels reported hearing thunder and seeing incandescent clouds. Locals would also report earthquakes as small volcanic eruptions rumbled across the island.

Little did they know that these were the early signs of what would become one of the biggest volcanic eruptions in recorded history. Krakatoa erupted on Sunday August 26th 1883, sending volcanic dust as high as 24km (15miles) into the atmosphere. The following day on August 27th, two enormous explosions were heard as far away as Australia, with the final eruption destroying two-thirds of the island and triggering a powerful tsunami that wiped away entire settlements and was felt all the way across the Indian Ocean in South Africa. It's estimated that 36,000 people died in this natural disaster.

The eruption also had a marked impact on the global climate, sending a very large amount of sulfur dioxide (SO2) into the stratosphere, which led to a global increase in sulfuric acid concentration. This in turn increased cloud coverage that dimmed sunlight, sending global temperatures down by at least 0.4°C the following year. As submarine telegraph cables were already in use, news about the eruption was relayed rapidly across the globe, hitting the newspapers in New York, London and Paris by August 28th.

Comet 2

New Comet C/2020 K8 (CATALINA-ATLAS)

CBET 4796 & MPEC 2020-L46, issued on 2020, June 12, announce the independent discovery of a comet (magnitude ~19) of an apparently asteroidal object made on CCD images taken with the 0.68-m Schmidt telescope of the Catalina Sky Survey (on May 25, 28, and 29) and the 0.5-m f/2 Schmidt reflector at Haleakala, Hawaii, in the course of the "Asteroid Terrestrial-Impact Last Alert System" (ATLAS) search program (on June 7). Then on June 8, R. Weryk reported the linkage of all of these tracklets, suggesting it might possibly be a comet based upon the astrometry. The object has been found to show cometary appearance subsequently by numerous CCD astrometrists at other observing sites after the object was posted on the Minor Planet Center's PCCP webpage. The new comet has been designated C/2020 K8 (CATALINA-ATLAS).
We performed follow-up measurements of this object while it was still on the PCCP webpage.

Stacking of 29 unfiltered exposures, 60 seconds each, obtained remotely on 2020, June 09.4 from X02 (Telescope Live, Chile) through a 0.6-m f/6.5 astrograph + CCD, shows that this object is a comet with a diffuse irregular coma about 10" in diameter (Observers E. Guido, M. Rocchetto, E. Bryssinck, M. Fulle, G. Milani, C. Nassef, G. Savini).

Stacking of 24 unfiltered exposures, 57 seconds each, obtained remotely on 2020, June 10.4 from U69 (iTelescope, Auberry California) through a 0.61-m f/6.5 astrograph + CCD, shows that this object is a comet with a diffuse coma about 15" in diameter slightly elongated toward PA 358 (Observers A. Valvasori, E. Guido).

Our confirmation images (click here for a bigger version)
Comet C/2020 K8 Catalina-Atlas
© Remanzacco Blogspot


India's Lake Lonar turns pink baffling scientists and locals

Maharashtra's Lonar Lake has turned pink overnight, leaving scientists and locals baffled about the reasons behind this change. Located in the Buldana district about 500 km from Mumbai, the Lonar crater had formed due to a meteorite, which hit the earth about 50,000 years ago.
Lonar Lake, India
© Outlook India
Water in the Lonar Lake, which has now turned Pink
This is the world's third-largest crater formed due to a meteorite strike. People in the area were considerably surprised when the lake's normal bluish-green water turned a pinkish red.

Comet 2

New Comet C/2020 K7 (PANSTARRS)

CBET 4790 & MPEC 2020-L09, issued on 2020, June 02, announce the discovery of a comet (magnitude ~20) in four 45-s w-band CCD images obtained with the Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala. The new comet has been designated C/2020 K7 (PANSTARRS).

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

Stacking of 8 unfiltered exposures, 180 seconds each, obtained remotely on 2020, June 02.2 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 6" in diameter and a tail 3" long in PA 306 (Observers E. Guido, M. Rocchetto, E. Bryssinck, M. Fulle, G. Milani, C. Nassef, G. Savini).

Our confirmation image (click here for a bigger version)

Comet C/2020 K7
© Remanzacco Blogspot

Fireball 3

Ancient accounts of 'Death from Above'

Meteorite Barage
© John Martin/Wikimedia Commons
Evidence suggests that a devastating barrage of meteorites rained down on the Dead Sea city of Tall el-Hammam in what is now Jordan. And, according to some researchers who think Tall el-Hammam was the biblical city of Sodom, that scenario could explain its destruction.
When we stargaze, we bask in photons that have traveled for many millennia before reaching our eyes. To us, the stars appear fixed on a so-called celestial sphere that encapsulates our entire earthly existence.

The truth, of course, is that no such sphere exists. Instead, stars and galaxies are scattered through the cosmos at distances so great they're incomprehensible to us.

But not all celestial phenomena exist so far away. Every day, shooting stars fail to recognize a boundary between space and Earth, dropping rocks from above — and often with dramatic results.

Our planet is vast, so meteorites typically don't concern us. But every once in a while, these objects actually strike humans and our property. Based purely on statistics, researchers estimate that a space rock should strike a human roughly once every nine years. And with those odds, you'd expect people to get killed by meteorites fairly often.

"I do strongly suspect that stats on 'death by asteroid' have been severely undercounted through human history," NASA Planetary Defense Officer Lindley Johnson told Astronomy via email. "It's only been in the last half century or so that we've even realized that such a thing could happen."

However, researchers still have not found a single confirmed case of death by space rock. But that's not to say we haven't come close. Modern history is full of near misses. On many occasions, space rocks have exploded over populated areas and sent thousands of meteorites raining down.

One of the most recent and well-known examples occurred in Chelyabinsk, Russia, in 2013, when a house-sized asteroid exploded over the city and injured some 1,200 people. Further back, on Jan. 30, 1868, a meteor exploded outside a town called Pultusk, near Warsaw, Poland, creating a literal meteor shower: More than 100,000 stones fell from the sky. The biggest recovered meteorite (a fragment of a space rock that makes it to the ground) weighed 20 pounds. It's the largest meteorite fall on record.

Fireball 5

Meteor fireball caught on camera over Armenia

Meteor Fireball
Videos of the suspected meteor's fall appear to suggest that it went down somewhere in the vicinity of the Armenian town of Hrazdan.

Residents of Armenia's Kotyak province were likely in for quite a surprise on the evening of 27 May as a flying object, which Public Radio of Armenia suggests might've been a meteor, flashed across the sky.

According to the media outlet, videos of this event that started emerging online show the object falling in the vicinity of the town of Hrazdan which is located about 45 kilometers northeast of the capital Yerevan.


Residents in New Zealand report mystery fireball 'crashing' into river

Waipuna bridge
© BBR Contech
Waipuna bridge: did a meteorite crash land into the Tamaki River?
Several Pakuranga residents reported seeing a bright flash of light or a "fireball" above the Tamaki River in the vicinity of Waipuna Bridge at around 6:47 pm on Monday 25 May. According to some eyewitnesses, the object was alleged to have then crashed into the water.

Reports of a "bright light" and "an explosion" flooded the east Auckland grapevine page as local people recounted what they had seen. Many speculated a meteor, a rocket from nearby Rocket Lab, or even a flare was responsible.

Corinne Hill, whose property on Pakuranga Rd backs on to the river saw "A Bright orange-red (object) about the size of 3 full moons joined together. It (sic) was travelling at speed over the water till it appeared to hit the water and disappeared."

According to Hill, the object made no sound, and by the time she "went to get binoculars out" it had gone.

Ms Hill also stated the object "It appeared to grow in size as it travelled, so my initial thought was it looked like a ball of fire but then I got wondering what it was. There were cars on the bridge at the time commuting, so I was thinking one of them may have also seen it."

Police, The Civil Aviation Authority (CAA), and Stardome observatory were approached for comment.


Chicxulub simulations reveal trajectory of impact

Chicxulub Crater
© Gareth Collins/Imperial College London
Asymmetries of the Chicxulub crater.
The asteroid that most believe wiped out the dinosaurs struck at the deadliest possible angle, according to new analysis combining 3D numerical impact simulations and geophysical data from the site.

The 66-million-year-old Chicxulub crater in Mexico was formed by a steeply inclined impact of between 45 and 60 degrees to the horizontal, the researchers suggest, which maximised the amount of climate-changing gases thrust into the upper atmosphere.

Such a strike likely unleashed billions of tonnes of sulphur, blocking the Sun and triggering the nuclear winter that killed 75% of life on Earth.

The researchers - from Imperial College London (ICL), the University of Freiburg, Germany, and the University of Texas, US - say their models are the first fully 3D simulations to reproduce the whole dramatic event, from the initial impact to the crater formation.

Reproducing the final stage, in which the transient crater collapsed to form the final structure, allowed them to make the first comparison between 3D simulations and the present-day structure of the crater.

"Our simulations provide compelling evidence that the asteroid struck at a steep angle, perhaps 60 degrees above the horizon, and approached its target from the northeast," says ICL's Gareth Collins, lead author of a paper in the journal Nature Communications.