The future of the universe looks bleak, but before it dies it will consume everything within it – including Earth and all life.
Geraint Lewis, an Astrophysicist at the University of Sydney, gave a timeline of how Earth, life and the universe will end.
He told an audience at New Scientist Live: “In about five billion years, something spectacular is going to happen.”
Prof Lewis states that Andromeda – the nearest galaxy to the Milky Way – is approaching us at around five million kilometres a year meaning that “in about three billion years, Andromeda will collide with ours.
“The collision will shake-up the Milky Way and it will be lit up like a Christmas Tree as new stars are created.
“The gas available in this collision gets used up very quickly. New stars will form and die. The gas will be swallowed up by a supermassive black hole.”
Prof Lewis said that our sun and the solar system could be “flung out in to intergalactic space”
But for any life still clinging on at this point, that could be the least of their worries.
This is because within that time scale, our sun is going to die.
Prof Lewis said: “The burning of helium in the sun will cause the sun to expand and within about three billion years, the Earth will be scorched by the growing sun.
“It will swallow Mercury, then Venus and then Earth.”
To survive this, any potential surviving humans will have to leave the solar system, or potentially the Milky Way galaxy altogether.
However, Prof Lewis said: “But the problem is that dark energy is causing the expansion of the universe to accelerate.
“And all of the distant galaxies will one day disappear from us completely – we will never be able to see them again.”
After this, in about 10 trillion years, new stars will be unable to form as the universe runs out of gas and raw material to make new stars
Prof Lewis: “As stars like the sun die, all we are left with are red dwarfs.”
Red dwarf stars are about 20 percent the size of the sun and it would be difficult for any planets orbiting these stars to sustain life as they are cold and temperamental, expelling harsh solar flares packed with radiation.
At this point, no life will be able to form and all that is left are dying stars and black holes.
And Prof Lewis stated that 100 trillion years from now: “The last star will go out, and the universe will finally go dark.”