[M-ZZ45] Planetary defense - what should we do?

[MZZ45-06] Southern Hemisphere Asteroid Radar Program (SHARP)

*Isabelle Savill-Brown¹, Shinji Horiuchi² (1.Australian National University, 2.CSIRO Space & Astronomy)

Keywords:near-Earth asteroids, radar

Astronomical radar observations have been used to probe surfaces of all the solid planets and many smaller bodies in the solar system. More recently, there has been considerable interest in using radar observations both to characterize near-Earth asteroids (NEAs) and determine their orbits more precisely. The motivation for radar observations of asteroids is three-fold. First, asteroids represent primitive remnants of the early solar system and characterization of their properties such as shape, rotation state and existence of satellites can provide insights into their evolution and parent population(s). Secondly, precise knowledge of their orbits is essential to assess the extent to which they might represent impact hazards to the Earth, and finally, they represent targets for spacecraft, both robotic and crewed. Over the past years we have successfully developed and demonstrated a Southern Hemisphere radar capability using the Canberra Deep Space Communication Complex (CDSCC) as transmitters and both the Parkes 64m Radio Telescope and the Australia Telescope Compact Array (ATCA) as receivers. Since the project started in 2015, we have successfully detected a total of 24 Near Earth Asteroids as of December 2022. Furthermore, our radar Doppler astrometry results also have contributed to refine orbits of the Near-Earth Asteroids. The key benefits of these observations are the further development of an Australian space radar capability, and contribution to improved understanding of near-earth asteroids and the early solar system. One of the remarkable recent achievements is the discovery of the binary system associated with the near Earth asteroid 2005 LW3 observed in November 2022.