WMAP (Wilkinson Microwave Anisotropy Probe)

The Wilkinson Microwave Anisotropy Probe (WMAP) was a NASA satellite launched in 2001 to study the cosmic microwave background radiation—an afterglow from the Big Bang. By measuring tiny temperature fluctuations in this radiation, WMAP provided crucial insights into the early universe's conditions and helped refine estimates of its age, composition, and expansion rate. The data gathered by WMAP has greatly enhanced our understanding of cosmology, confirming the existence of dark energy and revealing that the universe is flat on large scales, which has significant implications for theories of its formation and evolution.