Co-Conveners: Yusuke Koshio (Okayama U.), Gabriel D. Orebi Gann (UC Berkeley/LBNL), Erin O'Sullivan (Uppsala), Irene Tamborra (NBIA)

This topical group covers neutrino detection from all natural sources, including the Sun, the Earth, and astrophysical sources. Specific topics include:

Early Universe

• Cosmic neutrino background: prospects for detection
• Neutrino flavor composition and impact on the nucleosythesis
• Absolute neutrino mass: prospects for measuring it

Geoneutrinos

• Flux and spectral measurements
• Separation of U/Th contributions, flux & mantle contributions 
• Geographical spread

Solar

• CNO: solar metallicity, solar model
• 8B spectral shape: sensitivity to NSI, matter effects, day/night
• Precision low-energy measurements (pp, pep): luminosity

Supernova

• Prospects for DSNB measurement
• Galactic supernova: flavor composition, pointing, supernova mechanism, BSM physics
• Pre-supernova neutrinos

Atmospheric

• Identifying prompt component
• Neutrino flavor conversion physics

Extragalactic

• The origin of high energy neutrinos and the birthplace of cosmic rays
• The physics of cosmic accelerators: neutrino flavour, energy spectrum, and BSM
• Cosmogenic neutrinos: GZK neutrinos and cosmic ray composition
• Cross sections at high energies