The Milky Way's Cosmic Dance: Unveiling the Collisions with Shakti and Shiva

The universe, a vast and intricate cosmic dance, has witnessed numerous collisions between galaxies over billions of years. One of the most significant of these was the early collision of our Milky Way with two massive galaxies, Shakti and Shiva, more than 12 billion years ago. This event, captured through advanced astronomical observations, has reshaped our understanding of our galaxy's past and growth.

Galactic Deities: Shakti and Shiva

Shakti and Shiva, revered in Hinduism, have now taken on new meaning. These names have been assigned to two galaxies that collided with our Milky Way in the early days of cosmic formation, sometime between 12 and 13 billion years ago. Just as in Hindu mythology, where Shiva and Shakti represent the masculine and feminine forces, their names now evoke the fundamental forces that shaped the Milky Way.

The Formation of the Milky Way

The Milky Way, the galaxy we inhabit, formed near the time of the Big Bang, approximately 13.7 billion years ago. It has since grown through the gravitational influence of surrounding gas and smaller galaxies, all forming a vast structure consisting of 200 to 400 billion stars spread across more than 100,000 light-years. The discovery of the Shakti and Shiva galaxies provides new insights into how this massive structure formed.

The Gaia Satellite: A Cosmic Detective

The European Space Agency's Gaia Satellite has played a crucial role in uncovering the secrets of the Milky Way. Utilizing its advanced capabilities, the satellite has traced the trajectories of millions of stars in our galaxy. One of its significant discoveries was the Gaia-Enceladus-Sausage Galaxy, which collided with the Milky Way about 8 to 11 billion years ago, increasing its star count by around 50 billion.

Identifying Shakti and Shiva

Now, through additional years of observation, two more such events have been identified from even earlier times. The Gaia Satellite has been instrumental in tracing 6 million stars to reveal the existence of the Shakti and Shiva galaxies. Galactic archaeology, a challenging but fascinating field, has shed light on the complex history of these collisions. During such mergers, vast gas clouds collide and compress, leading to intense star formation and supernovas that further compress the gas and spawn more stars.

Star Kinetics and Composition

The Shakti and Shiva galaxies can be identified through their unique star populations. These stars share similar kinematics, indicating the direction of their movement and angular momentum. Additionally, older stars in these galaxies have lower abundances of elements heavier than hydrogen and helium. Such characteristics have helped astronomers discern the impact of these galaxies on the Milky Way.

The Collisions and Their Impact

The Milky Way, being a massive galaxy, has absorbed numerous smaller galaxies throughout its history. The Gaia-Enceladus-Sausage, Shakti, and Shiva were just the most significant collision events that occurred during these billions of years. These collisions not only added stars to the Milky Way but also influenced its structure and growth, setting the stage for the vast galaxy we know today.

Conclusion

The discovery of the Shakti and Shiva galaxies has enriched our understanding of the Milky Way's evolutionary history. These early cosmic collisions played a pivotal role in shaping our galaxy into the vast structure it is today. The ongoing study of galactic mergers continues to unlock the secrets of the universe, revealing its dynamic and ever-changing nature.