(175706) 1996 FG3 is a carbonaceous asteroid and binary system,[4] classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 1.7 kilometers (1.1 miles) in diameter. The primary has a spheroidal shape. Its minor-planet moon measures approximately 490 meters (1,600 feet) in diameter.
 | |
| 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 | 17.96 yr (6,560 d) |
| Aphelion | 1.4224 AU |
| 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° | |
| Known satellites | 1[3][4] (diameter: 0.49±0.08 km)[5] (orbital period: 16.1508 h)[6] |
| Earth MOID | 0.0283 AU (11 LD) |
| Physical characteristics | |
Mean diameter | 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] | |
It was discovered on 24 March 1996, by Australian astronomer Robert McNaught at Siding 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]
Numbering and naming edit
This minor planet was numbered by the Minor Planet Center on 21 February 2008.[20] As of 2021, it has not been named.[1]
Orbit and classification edit
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 an eccentricity of 0.35 and an inclination of 2° with respect to the ecliptic.[2] It has an Earth minimum orbital intersection distance of 0.0283 AU (4,230,000 km), which corresponds to 11.0 lunar distances.[2] In 2019 a precovery observation from Palomar Mountain was found, extending the body's observation arc into 1985.[1]
Physical characteristics edit
The carbonaceous body is characterized as a rare B-type and hydrated C-type (Ch) asteroid, respectively.[11][15]
Lightcurves edit
Several rotational lightcurves of this asteroid were obtained from photometric observations taken by astronomers Petr Pravec, Petr Scheirich and Stefano Mottola, as well as by the Very Large Telescope's VISR instrument. Lightcurve analysis gave a well-defined rotation period of 3.594 to 3.595 hours with a brightness variation of 0.08 to 0.10 magnitude (U=3/3/3/3).[6][8][9][12][21] The asteroid is an oblate ellipsoid with a nearly spherical shape.[6][22]
Diameter and albedo edit
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]
Satellite edit
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] an orbital 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.
Exploration edit
Rejected Marco Polo mission edit
Due to its binary nature and its low delta-v heliocentric orbit (also see Hohmann transfer orbit),[11] this asteroid was selected for MarcoPolo-R, which was the Marco Polo spacecraft's first proposed mission. MarcoPolo-R was originally selected for the assessment study phase in the M3 slot of ESA's Cosmic Vision program, but rejected in favor of PLATO by the end of 2012.[6][22]
Janus spacecraft edit
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]
Planned Chinese mission edit
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]
See also edit
- (35107) 1991 VH, binary near-Earth asteroid and former target of the Janus Mayhem mission, until the launch delay made the target inaccessible
References edit
External links edit
- Asteroids with Satellites, Robert Johnston, johnstonsarchive.net
- Asteroid (175706) 1996 FG3, Small Bodies Data Ferret
- List of the Potentially Hazardous Asteroids (PHAs), Minor Planet Center
- Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
- Dictionary of Minor Planet Names, Google books
- (175706) 1996 FG3 at NeoDyS-2, Near Earth Objects—Dynamic Site
- (175706) 1996 FG3 at ESA–space situational awareness
- (175706) 1996 FG3 at the JPL Small-Body Database
