Yes, this is what will happen to our Solar System in the future<\/a>, but this planet-sterilising red giant phase won\u2019t begin for another 5 billion years or so<\/p>\n So a natural question might be what could we do in the distant future to try to preserve the habitability of our world?<\/p>\n Various high-concept proposals have been put forward, including a carefully orchestrated programme of flinging asteroids<\/a> past Earth to boost the planet into a more distant orbit as the Sun brightens, exploiting the same physics as the gravitational slingshot method used to propel space probes.\u00a0<\/span><\/p>\n Matthew Scoggins and David Kipping, both at Columbia University\u2019s department of astronomy<\/a> in New York, have been investigating another ultra-long-term, high-tech possibility.<\/p>\n One way for an advanced civilisation to counteract the brightening of their star as it ages is to progressively remove mass from it and so slow the rate of fusion reactions in its core.<\/p>\n Scoggins and Kipping dub such artificially engineered suns \u2018Lazarus stars\u2019, after the biblical figure raised from the dead.<\/p>\n Although they note that this method of \u2018star-lifting\u2019 was proposed by David Criswell back in 1985, here the authors have actually done the numerical calculations to work out exactly what would be needed.<\/p>\n So, could this be done? The astronomers considered two slightly different scenarios.<\/p>\n The first keeps the Sun at a constant brightness, or isoluminosity, by stripping mass from it and then storing it in orbit between Earth and the Sun.<\/p>\n The second approach maintains the same amount of sunlight falling on Earth \u2013 isoirradiance \u2013 by removing less solar mass at first but then ejecting it out of the Solar System so that the orbit of the planet also drifts outwards with the reduced gravitational hold.\u00a0<\/span><\/p>\n Scoggins and Kipping calculate that changing the planet\u2019s orbit with the isoirradiance approach can extend the Sun\u2019s lifetime on the main sequence \u2013 and thus the potential for life on Earth \u2013 by around 6 billion years.<\/span><\/p>\n![\"""\"](\""https:\/\/images.immediate.co.uk\/production\/volatile\/sites\/25\/2022\/10\/hubble-halloween-image-cw-leonis-1c23b0a.jpg?quality=90&resize=620%2C413"\" "\\"\"\"\\"\/")
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<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>How to remove mass from the Sun<\/strong><\/h2>\n
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