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.



Climate Change Causing More Change in Rainfall, Fiercer Typhoons, Scientists Say 

People and vehicles wade through the water along a street that was flooded by Typhoon Gaemi in Kaohsiung on July 25, 2024. (AFP)
People and vehicles wade through the water along a street that was flooded by Typhoon Gaemi in Kaohsiung on July 25, 2024. (AFP)
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Climate Change Causing More Change in Rainfall, Fiercer Typhoons, Scientists Say 

People and vehicles wade through the water along a street that was flooded by Typhoon Gaemi in Kaohsiung on July 25, 2024. (AFP)
People and vehicles wade through the water along a street that was flooded by Typhoon Gaemi in Kaohsiung on July 25, 2024. (AFP)

Climate change is driving changes in rainfall patterns across the world, scientists said in a paper published on Friday, which could also be intensifying typhoons and other tropical storms.

Taiwan, the Philippines and then China were lashed by the year's most powerful typhoon this week, with schools, businesses and financial markets shut as wind speeds surged up to 227 kph (141 mph). On China's eastern coast, hundreds of thousands of people were evacuated ahead of landfall on Thursday.

Stronger tropical storms are part of a wider phenomenon of weather extremes driven by higher temperatures, scientists say.

Researchers led by Zhang Wenxia at the China Academy of Sciences studied historical meteorological data and found about 75% of the world's land area had seen a rise in "precipitation variability" or wider swings between wet and dry weather.

Warming temperatures have enhanced the ability of the atmosphere to hold moisture, which is causing wider fluctuations in rainfall, the researchers said in a paper published by the Science journal.

"(Variability) has increased in most places, including Australia, which means rainier rain periods and drier dry periods," said Steven Sherwood, a scientist at the Climate Change Research Center at the University of New South Wales, who was not involved in the study.

"This is going to increase as global warming continues, enhancing the chances of droughts and/or floods."

FEWER, BUT MORE INTENSE, STORMS

Scientists believe that climate change is also reshaping the behavior of tropical storms, including typhoons, making them less frequent but more powerful.

"I believe higher water vapor in the atmosphere is the ultimate cause of all of these tendencies toward more extreme hydrologic phenomena," Sherwood told Reuters.

Typhoon Gaemi, which first made landfall in Taiwan on Wednesday, was the strongest to hit the island in eight years.

While it is difficult to attribute individual weather events to climate change, models predict that global warming makes typhoons stronger, said Sachie Kanada, a researcher at Japan's Nagoya University.

"In general, warmer sea surface temperature is a favorable condition for tropical cyclone development," she said.

In its "blue paper" on climate change published this month, China said the number of typhoons in the Northwest Pacific and South China Sea had declined significantly since the 1990s, but they were getting stronger.

Taiwan also said in its climate change report published in May that climate change was likely to reduce the overall number of typhoons in the region while making each one more intense.

The decrease in the number of typhoons is due to the uneven pattern of ocean warming, with temperatures rising faster in the western Pacific than the east, said Feng Xiangbo, a tropical cyclone research scientist at the University of Reading.

Water vapor capacity in the lower atmosphere is expected to rise by 7% for each 1 degree Celsius increase in temperatures, with tropical cyclone rainfall in the United States surging by as much as 40% for each single degree rise, he said.