The end of the Milky Way - concluded
It has now been officially confirmed that our galaxy will collide with Andromeda galaxy in approximately 4 billion years. If our earth survived throughout the 4 billion years (ignoring global warming and other destructive cosmic events), it’d be quite a site to witness.
Explained to us by Ron Cowen at Nature Journal:
“For decades, scientists have known that Andromeda is falling towards our home Galaxy at a rate of 110 kilometres per second and that the two might eventually collide as a result of their mutual gravity. But because astronomers could easily measure Andromeda’s velocity only along the line of sight to Earth, no one could be sure whether the future encounter would constitute a major merger, a near-miss or a glancing blow.
Hubble’s visual acuity in recording the transverse or sideways motion of 15,000 stars in different parts of Andromeda has now provided the missing components of the galaxy’s motion. In determining that the overall sideways velocity of Andromeda is much smaller than its line-of-sight speed, van der Marel and his colleagues have shown that a merger of Andromeda and the Milky Way is inevitable. Four billion years from now, the two galaxies will pass through each other and, 2 billion years after that, they will fall back in a permanent embrace to form a single galaxy, the team’s simulations show…
The Milky Way–Andromeda collision will almost certainly move the Sun outwards from its current position 8,000 parsecs (26,000 light years) away from the Galactic centre. The simulations show a 10% chance that the Solar System will be exiled to a Galactic Siberia, more than 50,000 parsecs (160,000 light years) from the centre of the merged bodies.”
