LuSEE (the Lunar Surface Electromagnetic Explorer) is a multi-launch project to explore the properties of low-frequency electromagnetism on the surface of the Moon. LuSEE-Night is a path-finder mission to land a radio telescope on the far side of the moon and take the most precise measurements of the sky at frequencies below 50MHz to date. It is a collaboration of the NASA and the Department of Energy, and is manifested on the CS-3 mission of the Commercial Lunar Payload Services in 2025. The instrument will consist of 2 orthogonal pseudo-dipoles feeding a full-bandwidth spectrometer operating at 0.1 - 50MHz, and achieving a nearly sky-dominated sensitivity across the observing band. The mission is designed to last 18 months after landing.
LuSEE-Night's sister LuSEE-Day will focus on lunar and solar plasma physics.
The primary goal of LuSEE-Night is to act as a pathfinder and to investigate the feasibility of measuring the fundamental physics processes occurring during the cosmic Dark Ages using instrumentation on the lunar surface. The "Dark Ages" refers to the cosmic era between the last scattering of the cosmic microwave background (CMB) and the time when the first stars and galaxies formed. Only cold, non-luminous hydrogen gas existed during this epoch, and so it has been largely unexplored and remains one of the least constrained frontiers of modern cosmology.The community has therefore shown increasing interest in developing an experimental Dark Ages program based on observations of the 21-cm hyperfine transition of neutral hydrogen, seen against the backlight of the CMB. The global (sky-averaged) spectrum of the redshifted 21cm line is sensitive to the temperature and ionization state of the hydrogen gas and provides a tomographic probe of the thermal history of the early universe, possibly including signatures of new physics beyond the standard model. The recent National Academies Decadal Survey on Astronomy and Astrophysics 2020 described Dark Ages cosmology as "...both the discovery area for the next decade and the likely future technique for measuring the initial conditions of the universe in the decades to follow."
Science Analysis for LuSEE-Night is done through LuSEE-Night Science Collaboration.