Radar observations

Radar astronomy is one of the most effective methods of Earth-based remote sensing of solar system objects. The size, shape, spin period, high spatial resolution radar maps, surface and subsurface physical properties can be obtained using radar observations. Such observations suggest a transmitting and receiving antenna systems, a highly sensitive equipment for detecting echo signals and a software for observations scheduling and data processing. The Institute of Applied Astronomy of the Russian Academy of Sciences (IAA RAS) regularly participates in international radar observations of NEOs [1,2] and the Moon. Usually, the sources of radio signals are the 70-meter antenna of the Goldstone Deep Space Communications Complex (USA) and, until 2021, the 305-meter radio telescope located at the Arecibo Observatory (Puerto Rico), equipped with powerful transmitters. Detection of signals reflected from asteroids is performed with 32-meter or 13.2-meter radio telescopes of the Russian VLBI Network Quasar. The first radar observations in IAA RAS were carried out in July 2015 in collaboration with the Jet Propulsion Laboratory of the California Institute of Technology and the Goldstone Observatory. The object of study was the potentially hazardous asteroid 2011 UW158 during its close approach to the Earth.

Radar observations of Near-Earth Objects

Observation Date Object Notes
2021 May 03 2021 AF8 Asteroid
2020 Nov 30 2020 SO Artificial Object
2020 Apr 19-22 1998 OR2 Asteroid
2018 Dec 17-22 2003 SD220 Asteroid
2018 Mar 05 2017 VR12 Asteroid
2017 Dec 15-18 3200 Phaethon Asteroid
2017 Sep 04 3122 Florence Triple Asteroid
2017 Apr 18-20 2003 BD44 Asteroid
2017 Apr 18-20 2014 JO25 Asteroid
2016 Oct 31 2003 YT1 Binary Asteroid
2016 Oct 29 2003 TL4 Asteroid
2015 Jul 18-19 2011 UW158 Asteroid

Radar detectability of near-Earth objects (NEO) for the RT-32 radio telescopes at 8560 MHz (3.5 cm). The dashed lines show the distance at which echoes from the NEOs with a given diameter can be detected at signal-to-noise ratio of 5. Calculations assume a signal transmitted by a 450 kW radar with a gain of 74 dB and reflected from a NEO with a rotation period of 0.5 h, 2.1 h, and 20.0 h and a radar albedo of 0.1 for the corresponding round-trip signal propagation time.

List of potential radar targets in 2021

Close-Approach Date Object
D, m
P, h
R, au
2021 Dec 11 4660 Nereus 18.4 560-1200 (~330) 15.1 0.02630 10.23
2021 Dec 17 2003 SD220 17.9 700-1600 285.0 0.03628 14.12

Radar observations of the Moon

Observation Date Region Notes
2021 Sep 07 Hadley Rima, Apollo 15 landing site
2021 Sep 07 Mare Serenitatis Lunar mare
2021 Sep 07 Copernicus Crater
2021 Sep 07 Tycho Crater
2021 Sep 01 Archimedes Crater
2021 Jul 05-07 Archimedes Crater
2020 Oct 26-29 Archimedes Crater
2020 Aug 13 Mare Imbirium Lunar mare
2019 Apr 26 Mare Imbrium Lunar mare, Chang'e 3 landing site


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  1. This website section is maintained by Dr. Yuri Bondarenko and Dr. Dmitrii Marshalov.

  2. This work was supported by the Russian Scientific Foundation grant No. 16-12-00071.