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Like Earth sail through the solar system, the wind is never at our back; with each turn, torrents of hot, charged particles called solar wind emerge from the sun, crashing into our planet at around 1 million mph (1.6 million km / h).
Lucky for us, Earth’s magnetic shield deflect and dismantle the strongest of these winds, allowing little more than a warm breeze to enter the planet’s atmosphere. For our troubles, we even have the opportunity to see a colorful light show – the northern Lights and australis, which sparkle in the sky as fleeing solar particles dance toward Earth’s magnetic poles.
It’s a good situation for now. But new research suggests that our planet magnetic shield may not always be this strong – and the solar wind will only get more and more powerful as our local star nears its ultimate demise.
Related: 15 unforgettable pictures of stars
In a study published on July 21 in the journal Monthly notices from the Royal Astronomical Society, a team of astronomers have calculated how the intensity of the sun’s solar wind will change over the next 5 billion years, when our star runs out of hydrogen fuel to burn and balloons in a huge red giant. By then, the sun’s wind will become so strong that it will erode the Earth’s magnetic shield, the researchers found. From there, much of the planet’s atmosphere will be projected into space – and with it, all remaining protection from harsh stellar radiation.
Any life on Earth that has managed to survive this long will be quickly eradicated, the authors said.
“We know that the solar wind in the past has eroded the Martian atmosphere, which unlike Earth does not have a large-scale magnetosphere, “study co-author Aline Vidotto, an astrophysicist at Trinity College Dublin, Ireland, said in a statement.” What we do not we did not expect to find is that the solar wind in the future could be as damaging even to planets that are protected by a magnetic field. “
The last breaths of the sun
Billions of years from now, our sun (like all stars in the universe) will eventually run out of hydrogen that powers nuclear reactions in its nucleus. Without this fuel, the solar core will start to contract on its own gravity, while the outer layers of the star begin to expand. Eventually, the sun will become a red giant – a huge red orb whose radius extends millions of miles beyond its current limits.
As the sun’s outer atmosphere expands, it will set all the planets in its path ablaze. Mercury and Venus will almost certainly be erased – and Earth can be too, according to NASA.
After about a billion years of expansion, the sun will collapse into a shriveled white dwarf, smoldering weakly for another few billion years before the lights go out completely.
If Earth can survive the sun’s violent transformation into a red giant, our planet will remain in a very different solar system than it is today. As the sun’s core contracts, its gravitational drive over the planets will weaken, causing all the planets that are not engulfed to drift about twice as far from the sun as they are today. , according to NASA. The radiation oozing from the giant red sun will also be much more intense than it currently is.
The authors of the new study wanted to know: what will be the intensity of this radiation and can the Earth’s magnetosphere survive the assault? In their work, the researchers modeled the winds of 11 different star types with masses varying from one to seven times the mass of the sun. The researchers found that as the diameter of the sun increases towards the end of its life, the speed and density of the solar wind fluctuates dramatically, alternately increasing and contracting the magnetic fields of all neighboring planets.
Ultimately, however, in the models, each planet’s magnetosphere was always “choked” by the intensity of the wind, the authors wrote in their study. According to the researchers, the only way for a planet to maintain its magnetic field throughout stellar evolution is for that planet to have a magnetic field 100 times stronger than that of Jupiter today – or more than 1,000 times stronger. stronger than that of Earth.
“This study demonstrates the difficulty of a planet in maintaining its protective magnetosphere throughout the giant branch phases of stellar evolution,” said lead author of the study, Dimitri Veras, astrophysicist at the University of Warwick in the UK, in the press release.
As well as being a fun reminder that life on Earth is doomed, this research has implications for the search for alien life. Some astronomers believe that white dwarf stars could potentially host habitable planets in their orbit, in part because these “dead” stars do not create solar winds. So, if life exists on an Earth-like planet around a white dwarf star, then that life must have evolved after the star’s violent red giant phase ended, the researchers wrote.
In other words, it is extremely unlikely that life on a planet could survive the death of its sun, but new life could arise from the ashes of the old once the sun shrivels and stops its strong winds. So the wind may be against us now, but one day it will be gone. Hopefully for some worlds in the universe it means new life and smooth navigation.
Originally posted on Live Science.
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