Astronomers finally know when our Milky Way galaxy will slam into the neighboring monster galaxy Andromeda. Andromeda also known as M31 is a spiral galaxy approximately 2.5 million light years away from Earth. It is the nearest major galaxy to Milky Way and is moving towards us at an insane speed of 110 km/s.
Astronomers have long suspected that one day Andromeda and Milky Way would collide with each other. The earlier estimates suggested that the collision would occur in about 3.9 billion years.
However, according to latest measurements from European Space Agency’s Gaia spacecraft, astronomers have determined that the collision would occur later than previously expected.
Gaia is a spacecraft specially designed to measure the positions, distances and motions of stars. The aim of the mission is to build the most precise 3D map of the stars in the nearby Universe.
Recently, Gaia focused on the stars in the two nearby major galaxies i.e. the Andromeda and the Triangulum galaxy. Using the data, astronomers were able to determine the three dimensional movements of these galaxies relative to ours.
Using the data, Astronomers were able to estimate that the head-on collision between Andromeda and Milky Way would begin in about 4.5 billion years which is 600 million years later than previously thought. Once the collision begins, simulations show that it would last for around 2 billion years and completely reshape our cosmic neighborhood.
The study also found out the possibility that either Triangulum is on an incredibly long six-billion-year orbit around Andromeda and has already fallen into it in the past, or it is currently on its very first infall.
You can check more details about this study here.