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.



Should You Stretch before Exercise? After? Never? Here’s What to Know

 Philadelphia Eagles stretch as they get ready during practice at NFL football training camp, Thursday, July 25, 2024, in Philadelphia. (AP)
Philadelphia Eagles stretch as they get ready during practice at NFL football training camp, Thursday, July 25, 2024, in Philadelphia. (AP)
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Should You Stretch before Exercise? After? Never? Here’s What to Know

 Philadelphia Eagles stretch as they get ready during practice at NFL football training camp, Thursday, July 25, 2024, in Philadelphia. (AP)
Philadelphia Eagles stretch as they get ready during practice at NFL football training camp, Thursday, July 25, 2024, in Philadelphia. (AP)

For many people of a certain age, high school gym class began with reaching for their toes. Then, over the years, we were told it was better to stretch after exercise.

It turns out, both those things can be true, but the differing advice has created some confusion.

Stretching can help make you more flexible, improve range of motion in your joints — and feel good. David Behm, who researches human kinetics at Memorial University of Newfoundland in St. John’s, Canada, offers this advice on when to stretch and how to do it safely:

Warm up first

It’s almost always good to stretch, but it’s better if you warm up first, said Behm, author of "The Science and Physiology of Flexibility and Stretching." He recommends a light aerobic activity such as jogging, walking or cycling for five or 10 minutes.

Follow that with some static stretching, the traditional way of reaching and holding a position (think back to that gym class). You can then do activity-specific dynamic stretching, in which you warm up the muscles with repetitive movements like leg lifts.

Behm says one minute is "the magic number" for how long to do static stretching per muscle group without fatigue.

Expand your definition of 'stretching'

Should you always stretch before exercising? If it's traditional stretching, not necessarily.

The better question, Behm says, is, "Should people increase their range of motion? Should people have better flexibility? And that is yes, because it helps prevent injuries. It helps with health. But you don’t have to stretch to achieve that."

Resistance training, for instance, can be an effective form of stretching, he said. Doing a chest press increases range of motion in your deltoids and pecs, whether with barbells, dumbbells or machines, so there is no need to stretch beforehand. Just make sure to start with a small amount of weight to warm up and then add more to train.

"You probably don’t have to do extra stretching unless you’re a gymnast, a figure skater, or even a golfer who needs a great range of motion through that swing," Behm said.

Nor do you need to stretch first if you’re going for a leisurely run. Simply start with a slow jog to warm up and then increase the pace.

Don't do it if it hurts

After exercise, "light stretching is OK, as long as you don't reach a point where you're feeling pain," Behm said. Since your muscles will be warm by that point, overdoing it makes you more likely to injure yourself.

Foam rollers can help with muscle recovery and have been shown to increase range of motion as well as stretching.

Do some static stretching before sports

If you’re playing a sport, Behm said, static stretching beforehand helps reduce muscle and tendon injury.

"If you’re going to do an explosive movement, change of direction, agility, sprint, any of these explosive activities that involve your muscles and tendons," he said, "you’re going to be stronger if you do static stretching."

People can especially get in trouble when they go back to a sport they used to play, whether it's tennis, surfing or any sort of team activity.

Also, stretch both sides equally. Lacking flexibility on one side also can lead to injury.

Sounds simple. Why all the confusion? Different studies over the years have either encouraged or discouraged stretching before exercise. Behm says that partly because some studies didn't reflect real-life conditions, or were designed with elite athletes in mind, not regular people.

"If you’re Usain Bolt, it makes a difference," said Behm. Not so much for the rest of us.