British researchers from Durham University made the startling discovery that a satellite galaxy – a smaller galaxy which orbits a more massive one, in this case the Milky Way – is heading inwards. When the satellite galaxy, dubbed the Large Magellanic Cloud (LMC), finally reaches the inside of the Milky Way, it could knock Earth off of its perch and shove our planet out of the Goldilocks Zone – the region in the solar system where temperatures are perfect for life to thrive. The consequences of this will be dire, and life on Earth will cease to exist at that point.
It will not be the LMC itself which will wreak havoc on Earth and our solar system, but the chain of events which will follow.
A gravitational push and shove will occur across the Milky Way, and the leaders of the study warn it could awaken a monster supermassive black hole at the centre of our galaxy.
Lead author Marius Cautun, a cosmologist at Durham University, said: “The destruction of the Large Magellanic Cloud, as it is devoured by the Milky Way, will wreak havoc with our galaxy, waking up the black hole that lives at its centre and turning our galaxy into an ‘active galactic nucleus’ or quasar.”
However, this is still along way off – but much sooner than expected.
Scientists believed that eventually the sun would expand to such a point that it consumes the Earth, before our host star dies in a massive supernova – this was not believed to be for around four billion years.
But new estimates suggest that the LMC will affect life on Earth within two billion years.
Dr Cautun added: Any such change is very dangerous for life, since even small variations in the distance between the Earth and the Sun can move our planet outside the Goldilocks zone and make it either too hot or too cold for life.
“While two billion years is an extremely long time compared to a human lifetime, it is a very short time on cosmic timescales.
“We don’t fully know how this will affect life on Earth, but we can make a few predictions.
“Our descendants will see a very different night sky, much darker than currently with only a small bright patch that will correspond to the Milky Way galaxy.
“Furthermore, it will be tremendously more difficult for our descendants to travel to other stars. Currently, the nearest star is four light years away.
“However, if our Solar System would be outside the Milky Way, the nearest star would be hundreds or even thousands of light years away.”