JAKARTA – NASA has given the green light for the development of its next small astrophysics mission, a space telescope called COSI that will explore the Milky Way by studying the formation of chemicals in the galaxy through gamma-ray observations.
When studying the chemical evolution of interstellar matter, scientists study the known universe across the electromagnetic spectrum to observe all forms of radiation, including gamma rays.
Gamma rays are interesting because they come from energetic events such as stellar explosions, matter devouring black holes, or large collisions between celestial bodies. On Earth, gamma rays are generated during nuclear explosions, a man-made catastrophic event that may one day save the planet from an asteroid impact.
JUST IN! NASA has selected a new space telescope proposal that will study the recent history of star birth, star death and the formation chemical elements in the Milky Way. Congratulations to the Compton Spectrometer and Imager (COSI) team! Watch for more: https://t.co/SbkVBfKFf7 pic.twitter.com/bwrjTMsQc8
— Thomas Zurbuchen (@Dr_ThomasZ) October 18, 2021
Gamma rays essentially serve as fingerprints to detect high-energy cosmic events. Because of their short wavelength, gamma rays are observed using detectors containing solid crystals, producing a phenomenon called Compton scattering.
The new space telescope commissioned by NASA relies on this phenomenon to do its job. Called the Compton Spectrometer and Imager (COSI), the machine is expected to launch in 2025 and is said to cost $145 million for the entire mission, minus launch costs.
The core goal of the COSI mission is to study the formation of chemical elements in the Milky Way and gather more information about events such as the creation of stars and their eventual death.
The telescope’s field of view covers 25 percent of the visible sky, and uses no less than sixteen 3D imaging, high spectral resolution germanium detectors (GeDs). The COSI project was selected from a group of 18 submissions that were resubmitted in 2019 as part of the space agency’s Astrophysics Explorers program.
COSI, which is a soft gamma ray survey telescope, will specifically study the gamma rays emanating from atoms that arise from events such as supernovae, essentially tracing the chemical history of the Milky Way galaxy. It also aims to unravel the mystery of the positron – a subatomic particle with the same mass as the electron but with the opposite charge. Or, in simple words, the positron is in the anti-particle for the electron.
The space telescope will also aim to find nucleosynthesis sites in the galaxy. For the unconscious, nucleosynthesis refers to the process of making atomic nuclei using particles such as protons and neutrons. It is believed that the first atomic nuclei formed minutes after the Big Bang explosion.
While developing the project, the team focused on improvements in key areas such as sensitivity, spectral resolution and sky coverage to ensure that COSI could help make some groundbreaking discoveries. COSI’s strength lies in its observations of soft gamma rays, a range of great importance for studies of the evolution of massive stars and supernova explosions. The NASA telescope will map emissions of certain Iron and Aluminum isotopes and look for traces of Titanium isotopes that appear after supernova explosions
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