Astronomers Discover Ancient ‘Big Wheel’ Galaxy That Defies Expectations

New Delhi: Twelve billion years ago, in the infancy of the universe, a massive spiral galaxy was already spinning. Known as the "Big Wheel," this galaxy has taken astronomers by surprise, forming much earlier than expected. Discovered by the James Webb Space Telescope, the Big Wheel challenges our understanding of galaxy evolution and suggests that the early universe may have been far more structured than scientists previously thought.

A Galaxy That Shouldn't Exist Yet It Does

The Big Wheel galaxy formed just 1.7 billion years after the Big Bang, at a time when the universe was only 15% of its current age. Most galaxies from this period are small, irregular, and still in the process of formation. 

However, the Big Wheel is a fully developed spiral galaxy, much like our Milky Way, and it is far larger than any other galaxy from its era. This discovery has stunned astronomers, as conventional models suggest that disk galaxies form slowly, over billions of years, through gas accumulation and mergers.

A Galactic Oddity: Size, Spin, and Structure

What makes the Big Wheel even more remarkable is its size and rapid motion. It is three times larger than other galaxies of its time and spins at a speed that perfectly matches the Tully-Fisher relation, which links a galaxy's mass with its rotation speed. This suggests that the galaxy underwent an intense early buildup of stars, gas, and dark matter. 

Despite its impressive size, however, the Big Wheel is not producing stars faster than other galaxies from the same period, hinting at a stable and gradual growth process rather than explosive star formation.

The Role of Location in Its Unusual Growth

The Big Wheel is located in a densely packed region of space, where the galactic density is ten times higher than the average. This crowded environment likely played a key role in its rapid formation. 

Instead of violent galactic mergers, which are typically associated with fast galaxy growth, the Big Wheel likely grew through more gentle interactions and inflows of gas. The gas entering the galaxy aligned with its rotation, feeding its expansion while preserving its spiral structure.

Finding the Big Wheel was a rare event. Current models suggest there was less than a 2% chance of encountering such a galaxy in this particular survey. Its discovery could mean that scientists need to rethink how galaxies evolved in the early universe. 

The Big Wheel might represent a new chapter in the story of galactic formation, one that could rewrite our understanding of cosmic history.