Planetary Radar—State-of-the-Art Review

• Published in: Remote sensing (Basel, Switzerland) Vol. 15; no. 23; p. 5605
• Main Authors: Virkki, Anne, Neish, Catherine, Rivera-Valentín, Edgard, Bhiravarasu, Sriram, Hickson, Dylan, Nolan, Michael, Orosei, Roberto
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.12.2023
• Subjects: 20th century; 21st century; Asteroid missions; Asteroids; Astronomical instruments; Comets; Earth; Geology; Ground penetrating radar; Ground-based observation; Jupiter; Mercury; Moon; Near-Earth Objects; Observatories; Planetary defense; Planetary geology; planetary radar; Radar; Radar data; Radar equipment; radar polarimetry; radar sounding; Radio telescopes; Remote sensing; Reviews; Science; Solar system; Space exploration; Space missions; Space ships; Space surveillance; Space vehicles; Spacecraft; State-of-the-art reviews; synthetic aperture radar; Telescope; Telescopes; the Moon
• ISSN: 2072-4292; 2072-4292
• DOI: 10.3390/rs15235605

Planetary radar observations have provided invaluable information on the solar system through both ground-based and space-based observations. In this overview article, we summarize how radar observations have contributed in planetary science, how the radar technology as a remote-sensing method for planetary exploration and the methods to interpret the radar data have advanced in the eight decades of increasing use, where the field stands in the early 2020s, and what are the future prospects of the ground-based facilities conducting planetary radar observations and the planned spacecraft missions equipped with radar instruments. The focus of the paper is on radar as a remote-sensing technique using radar instruments in spacecraft orbiting planetary objects and in Earth-based radio telescopes, whereas ground-penetrating radar systems on landers are mentioned only briefly. The key scientific developments are focused on the search for water ice in the subsurface of the Moon, which could be an invaluable in situ resource for crewed missions, dynamical and physical characterization of near-Earth asteroids, which is also crucial for effective planetary defense, and a better understanding of planetary geology.