Відділ дистанційного зондування планет

Principal directions of research:

(1) development of theoretical and experimental models of light scattering in regolith-like media;

(2) analysis of optical and radar data on planetary surfaces obtained by earth-based telescopes and spacecrafts.

Basic results obtained in the Department:

  • A new approach has been developed to study polarimetric properties of the Moon at large phase angles, which makes it possible to map the average regolith particle size for some regions of the nearside of the Moon.
  • A theoretical model has been advanced for the negative polarization of the light scattered by atmosphereless celestial bodies at small phase angles; the model is based on the coherent enhancement of backscatter.
  • Theoretical and computer models have been suggested for the shadow and interference components of the phase dependence of brightness of regolith-like surfaces; the models has been used for interpretation of the data obtained by Clementine.
  • A theoretical model has been developed for spectral albedo of multicomponent regolith-like surfaces with different types of particle structure and composition; the model has been applied to the various celestial bodies (The Moon, Phobos, and asteroids).
  • On the base of calculations and laboratory data, an alternative explanation has been proposed to 3 micron absorption band in low-resolution reflectance spectra of some asteroids: chemical trapping of solar wind protons and formation of OH groups in the superficial zones oxygen-bearing regolith particles; so the 3 micron absorption can take place without presence of water molecules on the surface.
  • Laboratory simulations of Phobos spectra have shown that its regolith particles can contain organic substance formed in solar wind proton bombardment of carbonaceous material.
  •  Fe, Ti and He3 (thermonuclear fuel) abundance for the nearside of the Moon has been mapped; the first map of lunar regolith maturity has been obtained.
  • On the base of Arecibo radar data as well as optical data the first map of the regolith thickness has been obtained for the nearside of the Moon.
  • Models of gravitational relaxation of the Maxwell mountains (Venus) have been proposed; they explained the tectonic structure distribution in this region observed by synthetic aperture radar on Magellan.
  • A method of measurements of height of small volcanoes on the Venus surface imaged by Magellan radar has been developed, which enabled an estimate of the thickness of volcanic plains for some regions of the surface.
  • Using the data of laser altimeter on Mars Global Surveyor, maps of roughness of the North hemisphere of the martian surface have been obtained for the bases of 0.5 to 25 km.
  • A catalog of optical characteristics of lunar regions has been compiled; the catalog includes photometric and polarimetric measurements (the department  researchers) and spectral data of C. Pieters (Brown University, USA).
  • A unique laboratory device (photometer-polarimeter)  has been made  for studies of light backscatter by surfaces of complex structure at extremely small phase angles; numerous measurements with the device constitute an experimental basis for testing theoretical models of opposition enhancement of brightness and negative polarization of light scattered by atmosphereless celestial bodies.
  • A new interpretation of the data of neutron spectrometer on the Lunar Prospector has been given: the excess hydrogen detected near the lunar poles can be explained by trapping of solar wind and galactic protons on radiation defects, higher H content in polar regions being due to lower escape probability at low temperature

Works of researchers of the department were awarded by the State Prize of Ukraine (1986) and Barabashov Prize of the Ukrainian National Academy of Sciences (1997).

Now the department works in close collaboration including  joint grants with many scientists, e.g.: C. Pieters and J. Head (Brown University, USA ),  R. Nelson (JPL, USA), P. Helfenstein (Cornell University, USA), K.Muinonen and J. Piironen (Helsinki Astronomical Observatory, Finland), G. Arnold and H. Hoffmann (DLR, Germany),  P.Pinet (Observatoir Midi-Pyrenees, France).