It was discovered on 24 March 1996, by Australian astronomer Robert McNaughtatSiding Spring Observatory in New South Wales, Australia.[1] The asteroid was a target of NASA's Janus Serenity space probe,[17] until the delay of the rocket launch made the target inaccessible.[18] In 2017, scientists from the Chinese Academy of Sciences' Purple Mountain Observatory revealed a plan to land a probe on this asteroid in 2029, as part of an asteroid exploration mission.[19]
According to numerous observations, including the EXPLORENEOs survey, NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission and the Spitzer Space Telescope, the asteroid measures between 1.55 and 1.90 kilometers in diameter and its surface has a low albedo of 0.03 to 0.05.[6][7][8][9][10][11] The Collaborative Asteroid Lightcurve Link adopts an albedo of 0.04 and a diameter of 1.90 kilometers.[14]
During the photometric observations in December 1998, the binary nature of this asteroid was revealed.[3][4] It was the first binary near-Earth asteroid for which eclipse events were detected in the visible spectrum.[11] The binary system has a diameter ratio of 0.28, a density of 1.4 g/cm3, and an ecliptic latitude of -84° for its mutual spin axis.[11] The asteroid moon is known by its provisional designation S/1998 (175706) 1. It has a diameter of approximately 490 meters,[5]anorbital period of 16.1508 hours, and a nearly circular orbit, with an eccentricity of 0.1 and a semi-major axis of approximately 3.4 primary radii.[11]: 2 The orbital period was later estimated to be around 16.15 hours.
The asteroid was a planned target of NASA's Janus Serenity space probe, which was scheduled to launch in 2022 alongside NASA's Psyche spacecraft, and to arrive at 1996 FG3 in 2026.[17]1996 FG3 became impossible to reach for Janus when the launch of Psyche was delayed.[18]
In 2017, Chinese scientists announced they plan to land a probe on 1996 FG3 after 2029 as part of its asteroid exploration mission.[19] The mission includes plans for fly-by of three asteroids (one of them is 99942 Apophis), and land on 1996 FG3 to conduct in situ sampling analysis on the surface, according to Ji Jianghui, a researcher at the Purple Mountain Observatory of the Chinese Academy of Sciences and a member of the expert committee for scientific goal argumentation of deep space exploration in China. The probe is also expected to conduct a fly-by of a third asteroid to be determined at a later time. The entire mission is expected to take about six years.[19]
^ abcdMainzer, A.; Grav, T.; Masiero, J.; Bauer, J.; Cutri, R. M.; McMillan, R. S.; et al. (November 2012). "Physical Parameters of Asteroids Estimated from the WISE 3-Band Data and NEOWISE Post-Cryogenic Survey". The Astrophysical Journal Letters. 760 (1): 6. arXiv:1210.0502. Bibcode:2012ApJ...760L..12M. doi:10.1088/2041-8205/760/1/L12. S2CID41459166.
^ abcdefghiPravec, Petr; Sarounová, Lenka; Rabinowitz, David L.; Hicks, Michael D.; Wolf, Marek; Krugly, Yurij N.; et al. (July 2000). "Two-Period Lightcurves of 1996 FG 3, 1998 PG, and (5407) 1992 AX: One Probable and Two Possible Binary Asteroids". Icarus. 146 (1): 190–203. Bibcode:2000Icar..146..190P. doi:10.1006/icar.2000.6375.
^Pravec, Petr; Harris, Alan W.; Kusnirák, Peter; Galád, Adrián; Hornoch, Kamil (September 2012). "Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations". Icarus. 221 (1): 365–387. Bibcode:2012Icar..221..365P. doi:10.1016/j.icarus.2012.07.026.