Crash of the Titans: Milky Way and Andromeda Galaxy

Milky Way and Andromeda Galaxy

The event, which will take place within 4,000 million years, will forever change the face of the sky and, the story of our solar system and its planets.

Researchers from NASA have after many years of studies, been able to calculate exactly the titanic collision between the Milky Way galaxy (our galaxy) and its nearest neighbor, Andromeda. The event, which will take place within 4,000 million years, will forever change the face of the sky and, the story of our sun and its planets.

In fact, we have long known that the Milky Way and its neighbor Andromeda were attracted to each other, and like any other love story, they are approaching each other in a sort of “cosmic dance” due to the force of gravity from the two giants. However, so far no one has been able to say with certainty whether the two galaxies end up in a giant collision, but instead, would pass very close to each other.

Now, thanks to very precise data on the movement of Andromeda obtained with the Hubble Space Telescope, the collision hypothesis becomes a fact. The two galaxies are in direct route and a collision is therefore inevitable. The event, during which the Milky Way and Andromeda will merge, giving rise to a new, giant elliptical galaxy, will occur within 4,000 million years.

“Roeland van der Marel explain that our data, from the Institute of Space Telescope Science in Baltimore – are statistically consistent with a frontal collision between Andromeda and the Milky Way.”

But think for a moment what it means, in a galactic context, the term “frontal collision”. The Milky Way, our home in the universe, has a diameter of about 100,000 light years (roughly a trillion km) and contains between 200,000 and 400,000 million stars. Our Sun is just one of them. Andromeda, at the other end, is even bigger, probably twice as big (although the exact extent is difficult to estimate) and contains, according to recent data from Spitzer, about one billion stars. It is two times more than our own galaxy.

Andromeda and the Milky Way are, in fact, the two largest members of the thirty that make up the Local Group of galaxies. When they meet, the two will merge, thousands of stars will come out fired at all directions, this amazing collision will take at least another couple of billion years to subside. Surprisingly, it is possible that the Sun and Earth (if it still exists by then) survive and be spared with a simple “gravitational kick” that will end up placing them, however, in a complete different position than the one they are occupying today.

Reaching the moon in one hour

Currently, Andromeda, also called M31, lies about 2.5 million light years away from us (one light year is 9.5 trillion km), but is to our galaxy the milky way in an significant speed of 400,000 km per hour. Or what is the same, to 91 km per second. To get an idea, with that speed we could reach the moon in less than an hour.

The simulations constructed by Hubble suggest that after the first run, at least 2,000 million years will be needed for the two galaxies to merge completely, its stars are placed in stable positions and emergence of a new and giant elliptical galaxy much like that abound in our sector of the universe.

However, despite that the future of the beautiful Andromeda is to be ’embedded’ within the Milky Way, the vast majority of stars forming the galaxies would not need to collide during the “encounter”. In fact, there is enough space between stars for the fusion to occur without too many individual collisions.

Yes, almost all of them will be driven to very different orbits of current around the new galactic center. The simulations show that, most likely, our solar system will be driven outwards, and will occupy a much farther position from the galactic core that we are positioned today.

And to further complicate things, another actor will join the collision, yet with a minor role, the Triangulum galaxy M33, a “small” satellite galaxy of Andromeda (which only has about 40,000 million stars) will also be involved in this “love story”.

Calculations indicate that M33 “flutter” around the two giants during their interaction, and only later will end deafening with the resulting new galaxy. There is, however, a tiny possibility that M33 directly collide with the Milky Way before the “big meeting” occurs.