PBS Space Time Season 2018 Episode 11 The Andromeda-Milky Way Collision

In season 2018 episode 11 of PBS Space Time titled "The Andromeda-Milky Way Collision," the show delves into the impending collision of the Milky Way and Andromeda galaxies. The episode discusses how long scientists have known about this inevitability and emphasizes the time scale, which is over 4 billion years away. However, the show's main focus is to answer the question: what will happen when the Milky Way and Andromeda galaxies finally merge?

The episode starts with an overview of the two galaxies, including their sizes, shapes, and how astronomers have observed their movements. The Milky Way is a barred spiral galaxy, which is unique because it has a central bar-shaped structure that extends out to spiral arms. Andromeda is a spiral galaxy, which means it has a flat disk shape with spiral arms that contain young stars and gas.

The episode then explains that the two galaxies are on a collision course due to their gravitational attraction towards each other. It highlights that scientists have used data obtained from the Hubble Space Telescope over the past few decades to study this collision process. PBS Space Time provides a visualization of what will happen when the galaxies come together, showing the chaotic interactions between stars, gas, and dust clouds.

The episode highlights the theoretical models that astronomers have used to predict the aftermath of the galaxy collision, emphasizing that it's an ever-evolving field. The predicted outcome of the collision is a new galaxy that forms from the merger, with both the Milky Way and Andromeda becoming a larger galaxy called Milkomeda. However, the episode delves into the challenges that come with predicting the exact details of the new galaxy's formation, as it depends on multiple unknown factors, such as the amount of dark matter and the trajectories of the galaxies at the time of collision.

PBS Space Time discusses how this galaxy collision is not a catastrophic event when it comes to human time scales and the significance of galaxy mergers in general. The episode explains that such mergers play a vital role in the evolution of the universe, including the creation of new stars and planets. It also touches on the fact that galaxies are not just beautiful objects to observe but are also tangible proof of how the universe has evolved. The final part of the episode is dedicated to addressing some common misconceptions people have about galaxy collisions and their aftermath.

The show's presenters carefully break down how the collision impacts the view of the night sky, stating that it won't make a significant difference to an observer's lifetime, but it's still fascinating to watch. The final moments of the episode discuss how scientists are using the galaxy collision to learn more about the universe's laws. They explain how following the collision, scientists will observe the black-hole ripples across the universe, and their observations will contribute to a better understanding of the universe's origins.

In conclusion, season 2018 episode 11 of the PBS Space Time series provides an engaging and informative look at the impending collision between the Milky Way and Andromeda galaxies. It illuminates the impact of such an event on the structure of the universe, the formation of galaxies, and how scientists can learn from the event. Overall, this episode is an excellent resource for anyone fascinated with astronomy or the study of the universe.