100m-Wide Meteor Hit Antarctica 430,000 Years Ago

 In a photo taken 10/22/17, near Malaga, Spain, a meteor is seen
streaking past the constellation Canis Minor during the annual Orionid
meteor showers. (Reuters)
In a photo taken 10/22/17, near Malaga, Spain, a meteor is seen streaking past the constellation Canis Minor during the annual Orionid meteor showers. (Reuters)
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100m-Wide Meteor Hit Antarctica 430,000 Years Ago

 In a photo taken 10/22/17, near Malaga, Spain, a meteor is seen
streaking past the constellation Canis Minor during the annual Orionid
meteor showers. (Reuters)
In a photo taken 10/22/17, near Malaga, Spain, a meteor is seen streaking past the constellation Canis Minor during the annual Orionid meteor showers. (Reuters)

Research led by a Kent-based space scientist has uncovered new evidence of meteor particles reaching the Antarctic ice sheet 430,000 years ago. The team said the findings highlight the importance of reassessing the threat of medium-sized asteroids, with the potential for destructive consequences, reported The Metro.

Researchers recovered extra-terrestrial particles on the summit of Walnumfjellet within the Sor Rondane Mountains in east Antarctica. The discovery indicated a so-called low-altitude meteoritic touchdown event – where a jet of melted and vaporized material from an asteroid at least 100 meters in size reached the surface at high velocity.

The impact covered a circular area of around 2,000km – an almost-continental scale distribution, said Dr. Matthias van Ginneken from the University of Kent's School of Physical Sciences.

The research, published in the Science Advances journal, said finding evidence of such events remains critical to understanding the impact history of Earth and estimating hazardous effects of asteroid impacts.

Ginneke said while it is highly unlikely that such an event would happen over a densely-populated area – with less than 1 percent of the surface of the earth considered densely populated – its effects can be widespread.

"Severe effects of such an impact can be felt over hundreds of kilometers. Therefore, even if such an impact were to occur hundreds of kilometers away from a densely populated area, the amount of devastation would not be negligible and would need to be taken into account", he said.

Ginneken said the study could help improve knowledge of the rate of such impacts in the past and therefore how often these might happen in the future. The paper states that these events are potentially entirely destructive over a large area, corresponding to the area of interaction between the hot jet and the ground.



Latest Tests Show Seine Water Quality Was Substandard When Paris Mayor Took a Dip

 Boats carrying members of delegations sail along the Seine during the opening ceremony of the Paris 2024 Olympic Games on July 26, 2024. (AFP)
Boats carrying members of delegations sail along the Seine during the opening ceremony of the Paris 2024 Olympic Games on July 26, 2024. (AFP)
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Latest Tests Show Seine Water Quality Was Substandard When Paris Mayor Took a Dip

 Boats carrying members of delegations sail along the Seine during the opening ceremony of the Paris 2024 Olympic Games on July 26, 2024. (AFP)
Boats carrying members of delegations sail along the Seine during the opening ceremony of the Paris 2024 Olympic Games on July 26, 2024. (AFP)

Tests results released Friday showed the water quality in the River Seine was slightly below the standards needed to authorize swimming — just as the Paris Olympics start.

Heavy rain during the opening ceremony revived concerns over whether the long-polluted waterway will be clean enough to host swimming competitions, since water quality is deeply linked with the weather in the French capital.

Paris Mayor Anne Hidalgo took a highly publicized dip last week in a bid to ease fears. The Seine will be used for marathon swimming and triathlon.

Daily water quality tests measure levels of fecal bacteria known as E. coli.

Tests by monitoring group Eau de Paris show that at the Bras Marie, E. coli levels were then above the safe limit of 900 colony-forming units per 100 milliliters determined by European rules on June 17, when the mayor took a dip.

The site reached a value of 985 on the day the mayor swam with Paris 2024 chief Tony Estanguet and the top government official for the Paris region, Marc Guillaume, joined her, along with swimmers from local swimming clubs.

At two other measuring points further downstream, the results were below the threshold.

The statement by Paris City Hall and the prefecture of the Paris region noted that water quality last week was in line with European rules six days out of seven on the site which is to host the Olympic swimming competitions.

It noted that "the flow of the Seine is highly unstable due to regular rainfall episodes and remains more than twice the usual flow in summer," explaining fluctuating test results.

Swimming in the Seine has been banned for over a century. Since 2015, organizers have invested $1.5 billion to prepare the Seine for the Olympics and to ensure Parisians have a cleaner river after the Games. The plan included constructing a giant underground water storage basin in central Paris, renovating sewer infrastructure, and upgrading wastewater treatment plants.