Category Astronomy/Space

Scientists find increase in Asteroid Impacts on ancient Earth by studying the Moon

Image depicts the change in impact rate modeled in this paper. Some of the craters used in the study on both the moon and Earth are highlighted in the background.
Credit: Data from NASA GSFC / LRO / Arizona State University; Artwork by Rebecca Ghent

A team of scientists has determined the number of asteroid impacts on the Moon and Earth increased by two to three times starting around 290 million years ago. Previous theories held that there were fewer craters on both objects dating back to before that time because they had disappeared due to erosion. The new findings claim that there were simply fewer asteroid impacts during that earlier period.

“Our research provides evidence for a dramatic change in the rate of asteroid impacts on both Earth and the Moon that occurred around the e...

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Waves in Saturn’s rings give precise measurement of planet’s rotation rate

This image of Saturn’s rings was taken by NASA’s Cassini spacecraft on Sept. 13, 2017. It is among the last images Cassini sent back to Earth.
Credit: NASA/JPL-Caltech/Space Science Institute

Saturn’s distinctive rings were observed in unprecedented detail by NASA’s Cassini spacecraft, and scientists have now used those observations to probe the interior of the giant planet and obtain the first precise determination of its rotation rate. The length of a day on Saturn, according to their calculations, is 10 hours 33 minutes and 38 seconds.

The researchers studied wave patterns created within Saturn’s rings by the planet’s internal vibrations. In effect, the rings act as an extremely sensitive seismograph by responding to vibrations within the planet itself.

Similar to Earth’s vibrations...

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Feathers: Better than Velcro?

You may have seen a kid play with a feather, or you may have played with one yourself: Running a hand along a feather’s barbs and watching as the feather unzips and zips, seeming to miraculously pull itself back together. That “magical” zipping mechanism could provide a model for new adhesives and new aerospace materials, according to engineers at the University of California San Diego.
Credit: University of California San Diego

Engineers detail bird feather properties that could lead to better adhesives (and aerospace materials). You may have seen a kid play with a feather, or you may have played with one yourself: Running a hand along a feather’s barbs and watching as the feather unzips and zips, seeming to miraculously pull itself back together.

That “magical” zipping mechanism coul...

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From Emergence to Eruption: Comprehensive Model Captures Life of a Solar Flare

Still image from an animated visualization of the solar flare modeled in the new study. The violet color represents plasma with temperature less than 1 million Kelvin. Red represents temperatures between 1 million and 10 million Kelvin, and green represents temperatures above 10 million Kelvin. See video at: https://youtu.be/kyhsBqB2x_Y
Credit: Courtesy Mark Cheung, Lockheed Martin, and Matthias Rempel, NCAR

A team of scientists has, for the first time, used a single, cohesive computer model to simulate the entire life cycle of a solar flare: from the buildup of energy thousands of kilometers below the solar surface, to the emergence of tangled magnetic field lines, to the explosive release of energy in a brilliant flash.

The accomplishment, detailed in the journal Nature Astronomy...

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