While it may not be of particular concern to us right now, future humanity (that is if they survive that long) will have to contend with the possibility of our galaxy, the Milky Way colliding with its immediate neighbour, the galaxy Andromeda.
This was confirmed by NASA scientists using the Hubble telescope, saying that in around 4 billion years or so, the Milky Way will collide with Andromeda but according to NASA this collision will not have catastrophic results, as the sun and the planets will not be affected owing to the fact that the distances between the respective celestial bodies is great. It has been further theorised that 2 billion years after the collision, the Milky Way and Andromeda will stand fused as a single galaxy and because of the increased gravitational forces, our solar system will be displaced. The NASA researchers also put forward the possibility of new star formations after the collision and even Andromeda’s consort galaxy, the Triangulum Galaxy, or M33, also fusing into this super-galaxy.
Commenting upon the findings, Roeland van der Marel, lead rsearcher on the study from Space Telescope Science Institute in Baltimore, US, said, "Today, the Andromeda Galaxy appears to us on the sky as a small fuzzy object that was first seen by ancient astronomers more than one thousand years ago. Few things fascinate humans more than to know what our cosmic destiny and future fate will be. The fact that we can predict that this small fuzzy object will one day come to engulf and enshroud our Sun and Solar System is a truly remarkable and fascinating finding."
At present the two galaxies are at a distance of 2.5 billion light years apart but are moving towards one another at a speed of around 400,000km/h. Dr Van der Marel continued, "It's necessary to know not only how Andromeda is moving in our direction but also what its sideways motion is, because that will determine whether Andromeda will miss us at a distance or whether it might be heading straight for us. Astronomers have tried to measure the sideways motion for over a century. However, this was always unsuccessful because the available techniques were not sufficient to perform the measurement,” adding that, “For the very first time, we've been able to measure the sideways motion - in astronomy, also known as proper motion - of the Andromeda Galaxy using the unique observational capabilities of the Hubble Space Telescope.”
Dr Van der Marel also spoke about the sun, saying that in 4 billion years time it would have spent most of its energy, expanding and heating up, also making life on earth quite difficult but he added that he doubted that humanity would still be around by then.