HILL ~ 70 per cent of all galaxies are spirals - Astronomy with Grant Christie - Audio

Without much public notice, the team running the Wilkinson Microwave Anisotropy Probe (WMAP) recently released results from the satellite's "seven-year data set," updating the five-year data released in 2008. This has led to a substantial tightening of the fundamental data that defines the universe. The Mystery of Spiral Galaxies. Today 70% of all galaxies are spirals (like the Milky Way) but in the early universe only 30% were spirals. How did they develop and why do they exist?