The Andromeda Galaxy is heading for us. It will collide with the Milky Way galaxy and create a much larger galaxy called Milkdromeda. Andromeda is more extensive than our galaxy at 152,000 light-years across. Compared to the Milky Way at around 100,000 light years in diameter. It’s a barred spiral galaxy with an estimated mass of 1 trillion suns. It is heading toward us at 70 miles per second.
Andromeda can be seen with the naked eye. October is the best time to view it. In the northern hemisphere, it will be high overhead on a clear night. It looks like a sizeable fuzzy star. It is the most distant object you can see with the naked eye, and it will only get more prominent in the sky. The best way to find Andromeda or any other celestial body is to use an app. I use Sky map on my android devices. SkyView is a decent alternative on your Apple device.
Galaxy Collisions
The Gemini North Telescope in Hawaii took the image below. It’s of the two galaxies, NGC 4568 and NGC 4567. They are in the process of colliding with each other to form one galaxy. It’s an ominous picture of what is to be the fate of our galaxy one day. Galaxies are mostly empty space. So the number of stars colliding with each other will be minimal. It will be common for planets to change orbits. Others will be hurled away by their host stars when other stars come near them.
Milkdromeda
As Andromeda approaches our galaxy, the two will pass by each other several times. Like a final dance of sorts before they become one galaxy. The supermassive black holes of each galaxy will eventually merge into one. The resulting galaxy, “Milkdromeda,” will be an elliptical galaxy. We are a part of a cluster of galaxies known as the Virgo Supercluster. This is our local group. It is thought that in over 100 billion years, Milkdromeda will collide with other surrounding galaxies to form a massive supergalaxy. It will be a sight to see if anyone is still around to see it.
Don’t Hold your breathe
Even at 70 miles per second, it will take approximately 5 billion years for Andromeda to reach us. At the same time, our sun will start to run out of fuel. It will expand into a red giant. Growing so large that it will most probably envelop the earth. Scorching everything on the surface and subsequently rendering it uninhabitable. We will hopefully have found a new home elsewhere in the stars. Andromeda will, however, continue to become larger and more significant in the sky. It should make for a gorgeous view 1 billion years from now.
Studying Messier 31
Also known as Messier 31, Andromeda is close enough that the new JWST can see its individual stars and study them. There are approximately 229 Red Giant stars within Andromeda’s spiral arms. Star formation is crucial in galaxy building. Andromeda may be essential in helping us understand our own galaxy. Studying Red Giants, which are older stars, allows us to know their actual age. Using spectroscopy, scientists can split the light of the star up into bands; this reveals the elements present in the star.
Stars Age
The first generation of stars only burned hydrogen and helium. Over time stars started producing heavier elements. Scientists can date stars by analyzing which of these elements are present. I discuss this in more depth in my star stuff article.
Spectroscopy has been revealing more planets. Scientists can procure the chemical makeup of some exoplanets. This is done by viewing the atmosphere as the planet transits its host star. I discuss this topic in depth on my exoplanet page. Give it a read if you have a minute.
