space Paradigm Challenge

The very first galaxies weren't flat discs like ours—they were shaped like long, skinny cigars.

arXiv · March 17, 2026 · 2603.13700

Bitao Wang, Yingjie Peng, Hua Gao

The Takeaway

By analyzing stellar motion with the James Webb Space Telescope, astronomers proved that early 'flattened' galaxies aren't just tilted pancakes, but actually three-dimensional spindle-like shapes. This reveals a fundamental, previously unknown stage in how the Milky Way and other galaxies originally evolved.

From the abstract

The Universe is now extensively populated by discy galaxies with coherent galaxy-wise stellar rotation. This disc prevalence has been deemed a late-time phenomenon because the penetrating cold gaseous streams in the early Universe ($z\gtrsim 2$) fuel the star formation in galaxies too intensively to allow for thin disc formation. However, recent images taken by the James Webb Space Telescope (JWST) unveiled a prominent population of low-mass galaxies at high redshifts with flattened shapes, wide