Why the Northern Hemisphere Needs a 30-40m Telescope and the Science at Stake: from Interstellar Visitors to Planetary Defence
J. de León, N. Pinilla-Alonso, P. Tanga, D. Souami, Z. Gray, A. Alvarez-Candal, B. Carry, R. de la Fuente Marcos, A. Delsanti, F. La Forgia, A. Migliorini, T. Müller, A. Penttilä, M. Popescu, C. Snodgrass, D. Oszkiewicz, C. Opitom, A. Campo-Bagatin, J. Licandro, R. Hueso, M. Lazzarin, S. Fornasier, R. Brunetto, J. A. de Abol Brasón, J. de Cos Juez, J. DeMartini, A. Donaldson, R. Dorsey, R. Duffard, J. Fernández Díaz, F. García de Leániz, R. Hevia Díaz, J. M. Gómez-Limón, O. Groussin, S. Iglesias Álvarez, T. Kohout, M. Kretlow, T. Le Pivert-Jolivet, M. Montero-Vega, N. Morales, K. Muinonen, J. L. Ortiz, G. P. Prodan, J. L. Rizos, J. E. Robinson, S. Rodríguez Cabo, J. Rodríguez Rodríguez, A. Rozek, P. Santos-Sanz, E. Tatsumi, F. Tinaut-Ruano, E. Villaver
TL;DR
The paper argues that to maximize scientific return from upcoming all-sky SSO surveys, the Northern hemisphere must host a 30-40m telescope to complement the ELT and achieve full-sky coverage. It delineates four science drivers—interstellar objects, distant trans-Neptunian objects, space-mission support, and planetary defence—and ties them to observing capabilities such as wide-field imaging, high-resolution spectroscopy, fast timing, and AO-assisted IFU observations. The authors contend that northern coverage is essential for timely follow-up, robust orbital and physical characterization, and testing formation and dynamical scenarios, thereby enabling rapid response to transient discoveries and potential hazards. They conclude that a Northern facility would synergistically complement Southern facilities, enabling comprehensive studies of SSOs in the 2030-2050 era and strengthening planetary defence readiness.
Abstract
Small Solar system Objects (SSOs) preserve the physical, chemical, and dynamical signatures of the Sun's protoplanetary disk. Upcoming surveys will discover vast numbers of new objects, yet their scientific value will depend on follow-up observations requiring far greater sensitivity and resolution than those currently available. A 30-m class telescope like the Extremely Large Telescope (ELT) will be transformative, but its Southern location will leave significant regions of the sky poorly covered or even non accessible. A Northern 30-40m telescope is therefore essential to achieve full-sky coverage and fully exploit the small body discoveries of the 2030-2050 era, in particular for targets of opportunity or unexpected discoveries, like those of interstellar objects and potentially hazardous asteroids, as well as for distant trans-Neptunian objects and space mission targets.