The mysteries of the Milky Way revealed by a gamma-ray telescope

NASA's Astrophysics Explorers Program received 18 proposals for telescopes in 2019, then selected and studied four and then, after a detailed review by a group of scientists and engineers, selected the gamma-ray telescope, called Compton Spectrometer and Imager (COSI), which is expected to be launched in 2025 to study the recent history of stellar birth, stellar death and the formation of chemical elements in the Milky Way.

Thomas Zurbuchen, associate administrator for the management of the the agency's science mission to Washington, said that "for more than 60 years, NASA has provided opportunities for inventive, small-scale missions to fill the knowledge gaps where we still seek answers," "COSI will answer questions about origin of the chemical elements in our galaxy, the same ingredients critical for the formation of the Earth ".

credits: NASA COSI will study gamma rays from radioactive atoms produced when massive stars exploded to map where chemical elements formed in the Milky Way. The mission will also probe the mysterious origin of our galaxy's positrons, also known as antielectrons - subatomic particles that have the same mass as an electron but have a positive charge.