In the realm of space events, a collision of galaxies may be on the horizon. Andromeda, the Galaxy-twin of our Milky Way, is hurtling towards us at a speed of 110 kilometers per second. Currently visible in the night sky as a faint spot, Andromeda will continue to grow in size until it dominates the entire sky, potentially leading to a physical clash with our galaxy. This collision could cause chaos, disrupting stars, including our sun, and sending them into intergalactic space.
Despite numerous studies suggesting the inevitability of this cosmic collision, its probability remains uncertain. Recent data from an international group of European scientists estimates the likelihood of a clash at only 50%. Taking into account the influence of other nearby galaxies, researchers have concluded that this event is not a foregone conclusion.
The Milky Way is a flat disc galaxy spanning about 120 thousand light years, housing billions of stars, gas and dust clouds, and an ultra-massive black hole at its center. Andromeda, located 2.5 million light years away, is also one of the largest galaxies in the local group, which includes around a hundred galaxies such as the Triangulum galaxy (M33) and the Large Magellanic Cloud, a Milky Way satellite.
Galactic collisions are not uncommon in space. Interactions between galaxies can lead to their fusion, forming a larger galaxy. This process alters star orbits significantly and can result in the creation of new star systems. Massive gas clouds in galaxies can also trigger the formation of numerous stars and the release of vast amounts of energy.
The relative movements of the Milky Way and Andromeda are a key factor in the potential collision. Unlike most galaxies in the universe, Andromeda is moving towards us, creating a “blue shift.” However, despite this motion, Andromeda’s lateral movement can potentially lead to a near miss with the Milky Way, avoiding a direct collision.
Recent studies have indicated that the likelihood of a collision is around 50% when considering only the Milky Way and Andromeda. However, factoring in other galaxies like the Triangulum galaxy and the Large Magellanic Cloud alters these odds. The presence of the Large Magellanic Cloud reduces the collision probability to 30% as it may divert the Milky Way. Conversely, the inclusion of the Triangulum galaxy brings the probability back up to 50%.