Near-Earth asteroid 6489 Golevka (1991 JX) was discovered by Eleanor F. Helin at Palomar Observatory on May 10, 1991. It is named to honor the success of the multinational radar observations of it in June 1995. The Goldstone 70-m antenna provided the transmission and echoes were received by the Russian 70-m antenna in Evpatoria and also by the Japanese 34-m antenna in Kashima. This experiment produced the first intercontinental radar observations and also initiated planetary radar astronomy in Japan. An initial suggestion on asteroidís name was GEK, composed from first letters of the antennas Goldstone-Evpatoria-Kashima, but finally, the asteroid's name GOLEVKA was made from leading letters of the antennas GOLdstone-EVpatoria-KAshima.




1)     Abstract for the "Asteroids, Comets, Meteors" Conference, July 8-12, 1999, Versailles, France. Abstract Book, p. 42.


Intercontinental Bistatic Radar Observations of 6489 Golevka (1991 JX)


A. L. Zaitsev (IRE, Russia), S. J. Ostro (JPL, USA), Y. Koyama (KSRC, Japan), D. K. Yeomans (JPL, USA), S. P. Ignatov (RISDE, Russia), M. Yoshikava (KSRC, Japan), D. Choate (JPL, USA), O. K. Margorin (MSS, Russia), R. A. Cormier (JPL, USA), A. G. Petrenko (EDSC, Crimea), R. Winkler (JPL, USA), V. V. Mardyshkin (IPA, Russia), R. F. Jurgens (JPL, USA), O. N. Rzhiga (IRE, Russia), J.Giorgini (JPL, USA), V. A. Shubin (IRE, Russia), M. A. Slade (JPL, USA), A. P. Krivtsov (IRE, Russia), Y. F. Koluka (MSS, Russia), D. V. Ivanov (IPA, Russia), A. W. Harris (DLR IPE, Germany), V. A. Ivanov (OKB MEI, Russia), M. N. Meshkov (OKB MEI, Russia), A. M. Nakamura (ISAS, Japan), G. Neukum (DLR IPE, Germany)


Unlike the major planets and MBAs, some near-Earth objects (NEOs) make their closest approaches to Earth at high northern declinations and therefore are visible simultaneously from both North America, Europe and/or Asia, providing occasional opportunities for intercontinental radar experiments. The first celestial target of intercontinental radar was NEA 1991 JX, which in June 1995 passed 0.034 AU from Earth at a declination of ~ 40 deg. High power (~ 0.5 MW) continuous-wave signals at 3.5 cm wavelength were transmitted towards the asteroid from the 70-m antenna DSS-14 at the JPL/NASA Goldstone Deep Space Communication Complex (DSCC) in California on 13, 14 and 15 June 1995 during several hours on each date. This illumination of the asteroid thus created an artificial radio source for astronomers anywhere on the asteroid-facing side of Earth. Five astronomical groups from Russia, Japan and Germany tried to detect asteroid echoes and two succeeded. Detections were obtained on each of the three days by the 70-m antenna at Evpatoria DSCC in Crimea and on June 15 by the 34-m antenna at Kashima Space Research Center in Japan. The Goldstone 34-m antenna DSS-13 monitored echoes throughout all the observations. From the results of the Goldstone-Evpatoria experiment it can be inferred that the asteroid is about 0.5 km across, is not very elongated, possesses considerable surface irregularity and is very reflective presumable due to a large near-surface bulk density. This first intercontinental radar astronomy experiment is a milestone in asteroid radar reconnaissance and international cooperation. Our multi-antenna configuration can be thought of as the first step toward a global radar network for continuous, comprehensive investigations of near-Earth asteroids and comets.



2)   A. L. Zaitsev, S. J. Ostro, S. P. Ignatov, D. K. Yeomans, A. G. Petrenko, D. Choate, O. K. Margorin, R. A. Cormier, V. V. Mardyshkin, R. Winkler, O. N. Rghiga, R. F. Jurgens, V. A. Shubin, J. D. Giorgini, A. P. Krivtsov, K. D. Rosema, Y. F. Koluka, M. A. Slade, A. L. Gavrik, V. B. Andreev, D. V. Ivanov, P. S. Peshin, Y. Koyama, M. Yoshikava, A. Nakamura. Intercontinental bistatic radar observations of 6489 Golevka (1991 JX). Planetary and Space Science, 45, 771-778 (1997).


3)   R. S. Hudson, S. J. Ostro, R. F. Jurgens, K. D. Rosema, J. D. Giorgini, R. Winkler, R. Rose, D. Choate, R. A. Cormier, C. R. Franck, R. Frye, D. Howard, D. Kelley, R. Littlefair, M. A. Slade, L. A. M. Benner, M. L. Thomas, D. L. Mitchell, P. W. Chodas, D. K. Yeomans, D. J. Scheeres, P. Palmer, A. Zaitsev, Y. Koyama, A. Nakamura, A. W. Harris, and M. N. Meshkov. Radar Observations and Physical Modeling of Asteroid 6489 Golevka. Icarus, 148, 37-51 (2000).