Welcome back to Cosmos in a Pod! I’m your host, Amitesh, and today we’re exploring the incredible story of our galactic home: the Milky Way Galaxy. From its ancient beginnings to its future collisions, let’s uncover the secrets of this vast collection of stars, planets, and dark matter.

Episode Highlights:

The Birth of the Milky Way

• Formed 13.8 billion years ago from fluctuations in the early universe’s density.
• Began as protogalaxies merging and forming the first stars (Population III stars).

The Galactic Disk

• Took shape about 10 billion years ago as gas settled into a rotating disk.
• Home to most of the galaxy’s stars, including spiral arms rich with gas and young stars.

The Central Bulge and Supermassive Black Hole

• The Milky Way’s core contains Sagittarius A*, a black hole with 4 million solar masses.
• The dense bulge around it houses some of the galaxy’s oldest stars.

The Galactic Halo

• An extended region containing ancient stars, globular clusters, and dark matter.
• Remnants of smaller galaxies are absorbed over billions of years.

Galactic Cannibalism

• Growth through mergers with smaller galaxies, such as the Sagittarius Dwarf Galaxy.
• Stellar streams provide evidence of these cosmic collisions.

The Spiral Structure

• A barred spiral galaxy with density waves triggering star formation in its arms.
• Our solar system resides in the Orion Arm, 26,000 light-years from the centre.

The Modern Milky Way

• Spans 100,000 light-years and contains 100 to 400 billion stars.
• Part of the Local Group, which includes the Andromeda Galaxy and 50 smaller galaxies.

The Future of the Milky Way

• In 4.5 billion years, it will collide with the Andromeda Galaxy, forming a new elliptical galaxy called Milkomeda.

Unanswered Questions

• How did Sagittarius A* form?
• What is the distribution of the galaxy’s dark matter?
• How do interactions with satellite galaxies shape its evolution?

Cosmic Perspective:

The Milky Way is our cosmic home, a dynamic system shaped by creation and destruction. By studying it, we deepen our understanding of the universe and our place within it.

Next Episode: Join us as we explore the intriguing concept of parallel universes—could there be other realities beyond our own?

Thank you for tuning in! If you enjoyed this episode, please subscribe, share, and leave a review. Until next time, stay curious and keep looking up. The universe is full of wonders waiting to be discovered!