 | |
| Discovery[1] | |
|---|---|
| Discovered by | R. H. McNaught |
| Discovery site | Siding Spring Obs. |
| Discovery date | 24 March 1996 |
| Designations | |
| (175706) 1996 FG3 | |
| 1996 FG3 | |
| Apollo · NEO · PHA[1][2] | |
| Orbital characteristics[2] | |
| Epoch 27 April 2019 (JD 2458600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 17.96yr (6,560 d) |
| Aphelion | 1.4224AU |
| Perihelion | 0.6853 AU |
| 1.0538 AU | |
| Eccentricity | 0.3497 |
| 1.08 yr (395 d) | |
| 11.261° | |
| 0° 54m 39.6s / day | |
| Inclination | 1.9911° |
| 299.69° | |
| 24.052° | |
| Knownsatellites | 1[3][4] (diameter:0.49±0.08 km)[5] (orbital period: 16.1508 h)[6] |
| Earth MOID | 0.0283 AU (11LD) |
| Physical characteristics | |
| 1.196±0.362 km[7] 1.55 km[8] 1.64±0.20 km[6] 1.69±0.18 km[9] 1.84±0.56 km[10] 1.90±0.28 km[11] | |
| 3.5942 h[8][9][12] | |
| 0.03±0.03[13] 0.039±0.012[11] 0.042±0.035[10] 0.046±0.014[9] 0.058[8] 0.072±0.039[7] | |
| SMASS =C[2] B[11][14] C/Ch[15] B–V =0.708±0.005[8] V–R =0.380±0.003[8] V–I =0.714±0.004[8] | |
| 17.76[7][8][10][11][14][16] 17.833±0.024[9] 18.4[1][2] | |
(175706) 1996 FG3 is a carbonaceousasteroid andbinary system,[4] classified asnear-Earth object andpotentially hazardous asteroid of theApollo group, approximately 1.7 kilometers (1.1 miles) in diameter. The primary has a spheroidal shape. Itsminor-planet moon measures approximately 490 meters (1,600 feet) in diameter.
It was discovered on 24 March 1996, by Australian astronomerRobert McNaught atSiding Spring Observatory in New South Wales, Australia.[1] The asteroid was a target ofNASA'sJanus 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]
Thisminor planet wasnumbered by theMinor Planet Center on 21 February 2008.[20] As of 2021, it has not beennamed.[1]
1996 FG3 orbits the Sun at a distance of 0.7–1.4 AU once every 1 years and 1 month (395 days;semi-major axis of 1.05 AU). Its orbit has aneccentricity of 0.35 and aninclination of 2° with respect to theecliptic.[2] It has an Earthminimum orbital intersection distance of 0.0283 AU (4,230,000 km), which corresponds to 11.0lunar distances.[2] In 2019 a precovery observation from Palomar Mountain was found, extending the body'sobservation arc into 1985.[1]
The carbonaceous body is characterized as a rareB-type and hydratedC-type (Ch) asteroid, respectively.[11][15]
Several rotationallightcurves of this asteroid were obtained fromphotometric observations taken by astronomersPetr Pravec, Petr Scheirich andStefano Mottola, as well as by theVery Large Telescope'sVISR instrument. Lightcurve analysis gave a well-definedrotation period of 3.594 to 3.595 hours with a brightness variation of 0.08 to 0.10magnitude (U=3/3/3/3).[6][8][9][12][21] The asteroid is anoblate ellipsoid with a nearly spherical shape.[6][22]
According to numerous observations, including the EXPLORENEOs survey, NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission and theSpitzer Space Telescope, the asteroid measures between 1.55 and 1.90 kilometers in diameter and its surface has a lowalbedo of 0.03 to 0.05.[6][7][8][9][10][11] TheCollaborative Asteroid Lightcurve Link adopts an albedo of 0.04 and a diameter of 1.90 kilometers.[14]
During the photometric observations in December 1998, thebinary nature of this asteroid was revealed.[3][4] It was the first binarynear-Earth asteroid for whicheclipse events were detected in the visible spectrum.[11] The binary system has a diameter ratio of0.28, a density of 1.4 g/cm3, and anecliptic latitude of -84° for its mutual spin axis.[11] Theasteroid moon is remains undesignated.[2] 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.
Due to its binary nature and its lowdelta-v heliocentric orbit(also seeHohmann transfer orbit),[11] this asteroid was selected forMarcoPolo-R, which was theMarco Polo spacecraft's first proposed mission. MarcoPolo-R was originally selected for the assessment study phase in theM3 slot ofESA'sCosmic Vision program, butrejected in favor ofPLATO by the end of 2012.[6][22]
The asteroid was a planned target ofNASA'sJanus Serenity space probe, which was scheduled to launch in 2022 alongside NASA'sPsyche spacecraft, and to arrive at1996 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 on1996 FG3 after 2029 as part of its asteroid exploration mission.[19] The mission includes plans for fly-by of three asteroids (one of them is99942 Apophis), and land on1996 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]
