COBE detects primordial CMB anisotropy
COBE detects primordial CMB anisotropy
Overview
In 1992 the COBE satellite's DMR instrument announced the detection of temperature anisotropies of about one part in 100,000 in the cosmic microwave background. These faint ripples are the imprints of primordial density fluctuations — the seeds from which every galaxy and cluster later grew. The result confirmed the gravitational-instability picture of structure formation and opened the era of precision cosmology later refined by WMAP and Planck.