The picture of the cosmic microwave background (CMB) radiation was taken using a specialized satellite known as the Cosmic Background Explorer (COBE) and later by the Wilkinson Microwave Anisotropy Probe (WMAP) and the Planck satellite. These missions were designed to study the early universe and its remnants, including the CMB.
Here's a brief overview of the process:
Discovery of CMB: The cosmic microwave background radiation was first predicted by George Gamow, Ralph Alpher, and Robert Herman in the 1940s as a remnant of the Big Bang. In 1964, Arno Penzias and Robert Wilson accidentally discovered the CMB while working with a large radio antenna at Bell Labs in New Jersey, USA. They noticed a persistent background noise that appeared to come from all directions in space, and after ruling out various possible sources, they realized they had stumbled upon the CMB.
COBE Mission: In 1989, NASA launched the Cosmic Background Explorer (COBE) satellite. One of the primary objectives of the COBE mission was to precisely measure the properties of the cosmic microwave background. It carried three main instruments: the Differential Microwave Radiometer (DMR), the Far Infrared Absolute Spectrophotometer (FIRAS), and the Diffuse Infrared Background Experiment (DIRBE).
Measurements: The DMR instrument on COBE was designed to detect tiny fluctuations in the temperature of the CMB across the sky. These fluctuations are crucial as they provide valuable information about the distribution of matter in the early universe and the seeds of structure formation that led to the formation of galaxies and galaxy clusters.
Data Analysis: COBE collected data over several years, and researchers meticulously analyzed the data to account for various sources of noise and potential interference. After extensive data processing and analysis, COBE's measurements of the CMB fluctuations were published in 1992, providing strong evidence for the Big Bang theory.
Follow-up Missions: Subsequent missions, such as the Wilkinson Microwave Anisotropy Probe (WMAP) and the Planck satellite, further refined the measurements of the CMB fluctuations with even higher precision. WMAP, launched in 2001, and Planck, launched in 2009, provided more detailed maps of the CMB, revealing more insights into the early universe's structure and evolution.
In summary, the picture of the cosmic microwave background was possible through the efforts of dedicated scientists and engineers who designed and launched specialized satellites to observe and analyze the faint radiation left over from the Big Bang. These missions have significantly contributed to our understanding of the universe's origins and its subsequent evolution.