When I was a nine-year-old, I distinctly remember worrying about the most irrelevant of things. These things ranged from quicksand to the far-fetched idea of alien abductions. But after retrospection, I am glad to have had these unusual worries. It made me curious and thirsty for knowledge.
Out of those seemingly huge dilemmas, the prospect of the Andromeda-Milky Way Collision appeals to me, even now. It is fascinating to understand the theoretical origin of human life and the extent to which we may go until it finally ends in nullity.
Andromeda, also known as Messier 31 (M31), is a spiral galaxy located about 2.5 million light-years from Earth, making it the most distant thing visible to your unaided eye. The Andromeda galaxy and our Milky Way galaxy reign as the two most massive and dominant galaxies within the Local Group of Galaxies. The studies also suggest that M33, the Triangulum Galaxy—the third largest and third-brightest galaxy of the Local Group—will participate in the collision event, too.
Galaxy collisions are a normal part of the universe’s evolution. Both Andromeda and the Milky Way bear signs of having already crashed into other galaxies. Andromeda boasts a large ring of dust in its center, giving it an interesting shape. Astronomers believe this dust may have formed when it swallowed an existing galaxy.
The two galaxies are hurtling toward one another at 402,000 kilometers per hour. But even at that speed, they will not meet for another four billion years. And when they meet, the two galaxies will collide head-on and fly through one another, leaving gassy, starry tendrils in their wakes. For eons, the pair will continue to come together and fly apart, scrambling stars and redrawing constellations until eventually, after a billion or so years have passed, the two galaxies will merge.
Then, the solar system will have a new cosmic address: A giant elliptical galaxy known as Milkomeda or Milkdromeda, formed by the collision and merger of the Milky Way and Andromeda.
Based on current calculations, scientists predict a 50% chance that in the merged galaxy, the Solar System will be swept out three times farther from the galactic core than its current distance. They also predict a 12% chance that the Solar System will be ejected from the new galaxy sometime during the collision.
How about life on Earth? Will earthly life survive the merger? Astronomers say that the luminosity, or intrinsic brightness, of our sun, is due to increase steadily over the next 4 billion years. As the sun’s luminosity increases, the amount of solar radiation reaching the Earth will also increase, making the surface temperature of the earth hot enough to melt lead. Hence, it seems likely that life on Earth will not exist 4 billion years from now.
The mortality of humans never ceases to overwhelm me. Everything that we have accomplished, our materialistic gains, all that we are today could be wiped away in a single second, owing to an unexpected cosmic catastrophe. It is time to give in to the fact that we are ephemeral according to the cosmic calendar and be grateful for every passing moment in our journey through this universe.
– Joanna Jose, 1 PUC (B)