{"id":48388,"date":"2024-06-10T11:55:57","date_gmt":"2024-06-10T10:55:57","guid":{"rendered":"https:\/\/www.innovationnewsnetwork.com\/?p=48388"},"modified":"2024-06-10T11:55:57","modified_gmt":"2024-06-10T10:55:57","slug":"how-interstellar-clouds-altered-earths-climate","status":"publish","type":"post","link":"https:\/\/www.innovationnewsnetwork.com\/how-interstellar-clouds-altered-earths-climate\/48388\/","title":{"rendered":"How interstellar clouds altered Earth\u2019s climate"},"content":{"rendered":"
Around two million years ago, Earth\u2019s climate had fallen into a deep freeze, with multiple ice ages coming and going until about 12,000 years ago.<\/p>\n
Scientists theorise that ice ages occur for a number of reasons, including the planet\u2019s tilt and rotation, shifting plate tectonics, volcanic eruptions, and carbon dioxide levels in the atmosphere.<\/p>\n
But what if drastic changes like these are not only a result of Earth\u2019s environment but also the Sun\u2019s location in the galaxy?<\/p>\n
In a new paper published in Nature Astronomy<\/em><\/a>, lead author and astrophysicist Merav Opher\u2014an astronomy professor at Boston University and fellow at Harvard Radcliffe Institute\u2014 found evidence that some two million years ago, the solar system encountered an interstellar cloud so dense that it could have interfered with the Sun\u2019s solar wind<\/a>.<\/p>\n The authors believe this shows that the Sun\u2019s location in space might shape the history of Earth\u2019s climate more than previously considered.<\/p>\n Our Solar System is covered in a protective plasma shield that emanates from the Sun, known as the heliosphere.<\/p>\n It protects us from radiation and galactic rays that could alter DNA, and scientists believe it\u2019s part of the reason life evolved on Earth as it did.<\/p>\n According to the latest paper, the interstellar cloud compressed the heliosphere in such a way that it briefly placed Earth and the other planets in the Solar System outside of the heliosphere\u2019s influence.<\/p>\n Opher, who\u2019s an expert on the heliosphere, said: \u201cThis paper is the first to quantitatively show there was an encounter between the sun and something outside of the Solar System that would have affected Earth\u2019s climate.\u201d<\/p>\n Now, she\u2019s shedding new light on how the heliosphere \u2013 where the Sun moves through space \u2013could affect Earth\u2019s atmospheric chemistry.<\/p>\n \u201cStars move, and now this paper is showing not only that they move, but they encounter drastic changes,\u201d Opher explained.<\/p>\n To study this phenomenon, the team looked back in time, using sophisticated computer models to visualise where the Sun was positioned two million years in the past.<\/p>\n They also mapped the path of the Local Ribbon of Cold Clouds system, a string of large, dense, very cold clouds mostly made of hydrogen atoms. Their simulations showed that one of the clouds close to the end of that ribbon, named the Local Lynx of Cold Cloud, could have collided with the heliosphere.<\/p>\n If that had happened, Earth would have been fully exposed to the interstellar medium, where gas and dust mix with the leftover atomic elements of exploded stars, including iron and plutonium.<\/p>\n \u201cThe outside pressure from the Local Lynx of Cold Cloud could have continually blocked out the heliosphere for a couple of hundred years to a million years,\u201d said Opher.<\/p>\n \u201cBut as soon as the Earth was away from the cold cloud, the heliosphere engulfed all the planets, including Earth.\u201d<\/p>\n It\u2019s impossible to know the exact effect the cold clouds had on Earth\u2019s climate, such as whether they could have spurred an ice age.<\/p>\n However, the sun has likely encountered a couple of other cold clouds in the interstellar medium in the billions of years since its birth.<\/p>\n Opher and her collaborators are now working to trace the Sun’s location seven million years ago and even further back.<\/p>\nInterstellar clouds placed our Solar System outside the heliosphere<\/h3>\n
Studying the patterns of cold clouds<\/h3>\n
Will we ever discover how cold clouds affected Earth\u2019s climate?<\/h3>\n