 Masursky imaged byCassini–Huygens in January 2000 | |
| Discovery[1] | |
|---|---|
| Discovered by | E. Bowell |
| Discovery site | Anderson Mesa Stn. |
| Discovery date | 3 May 1981 |
| Designations | |
| (2685) Masursky | |
| Pronunciation | /məˈzɜːrski/ |
Named after | Harold Masursky[1] (Americanplanetary geologist) |
| 1981 JN · 1950 VO 1973 QF · 1975 XJ5 1977 KU | |
| main-belt[1][2] · (middle) Eunomia[3] | |
| Orbital characteristics[2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 44.58yr (16,282 d) |
| Aphelion | 2.8522AU |
| Perihelion | 2.2874 AU |
| 2.5698 AU | |
| Eccentricity | 0.1099 |
| 4.12 yr (1,505 d) | |
| 54.965° | |
| 0° 14m 21.48s / day | |
| Inclination | 12.129° |
| 215.36° | |
| 288.47° | |
| Physical characteristics | |
| 10.744±0.170 km[4] | |
| 0.114±0.034[5] | |
| S[6] | |
| 12.1[2] | |
2685 Masursky, provisional designation1981 JN, is a stony Eunomianasteroid from the central regions of theasteroid belt, approximately 11 kilometers (6.8 miles) in diameter. It was discovered on 3 May 1981, by American astronomerEdward Bowell at theAnderson Mesa Station near Flagstaff, Arizona, and named after American planetary geologistHarold Masursky.[1] In January 2000, theCassini space probe observed theS-type asteroid from afar during its coast to Saturn.[7]
Masursky is a member of theEunomia family (502),[3] a prominentfamily of stony asteroids and the largest one in the intermediate main belt with more than 5,000 members.[8]
It orbits the Sun in thecentral main-belt at a distance of 2.3–2.9 AU once every 4 years and 1 month (1,505 days;semi-major axis of 2.57 AU). Its orbit has aneccentricity of 0.11 and aninclination of 12° with respect to theecliptic.[2] The asteroid was first observed as1950 VO atMcDonald Observatory in November 1950. The body'sobservation arc begins with its observation as1973 QF atCerro El Roble Observatory in August 1973, nearly 8 years prior to its official discovery observation at Anderson Mesa.[1]
Little was known aboutMasursky until theCassini–Huygens space probe, en route toJupiter andSaturn, flew past it on 23 January 2000. BecauseCassini passed the asteroid at a distance of 1.6 million kilometers (approximately 4lunar distances), the images it returned showed nothing more than a dot.[7]
Cassini's observations had cast some doubt on its composition,[7] but later ground-based spectroscopy has confirmed its stonyS-type spectrum,[6] which is also the Eunomia family's overallspectral type.[8]: 23
During its flyby in January 2000, Cassini–Huygens estimated amean diameter of approximately 15–20 kilometers, based on anangular diameter of 0.81–1.08arcseconds just hours before its closest approach.[7] According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Masursky measures 10.744 kilometers in diameter and its surface has analbedo of 0.114.[4][5]
As of 2018, no rotationallightcurve ofMasursky has been obtained fromphotometric observations. The body'srotation period,spin-axis and shape remain unknown.[2]
Thisminor planet was named afterHarold Masursky (1922–1990), aplanetary geologist at theUSGS Astrogeology Science Center of theU.S. Geological Survey, in Flagstaff, Arizona. Masursky worked on numerous space missions and programs includingRanger,Surveyor,Lunar Orbiter,Apollo,Mariner 9,Viking,Pioneer Venus,Voyager, as well as on theGalileo andMagellan spacecraft.[1] The official naming citation was published by theMinor Planet Center on 4 August 1982 (M.P.C. 7158).[9]
