(66391) Moshup

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Asteroid
(66391) Moshup
(66391) 1999 week 4
Properties of the orbit ( animation )
Epoch:  April 27, 2019 ( JD 2,458,600.5)
Orbit type Aten type
Major semi-axis 0.6421  AU
eccentricity 0.6887
Perihelion - aphelion 0.1999 AU - 1.0844 AU
Inclination of the orbit plane 38.88 °
Sidereal period 187.97 d
Mean orbital velocity 34.82 km / s
Physical Properties
Medium diameter 1.317 km
Dimensions 1.532 km × 1.495 km × 1.347 km
Dimensions (2.35 ± 0.1) x10 12Template: Infobox asteroid / maintenance / mass kg
Albedo approx. 0.3
Medium density 1.97 ± 0.24 g / cm³
Rotation period 2 h 45 min 52.2 s
Absolute brightness 16.5 mag
Spectral class S.
history
Explorer LINEAR
Date of discovery May 20, 1999
Another name 1999 week 4
Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . The affiliation to an asteroid family is automatically determined from the AstDyS-2 database . Please also note the note on asteroid items.

(66391) Moshup (provisional name 1999 week 4 ) is a near-Earth asteroid that crosses the earth's orbit and whose perihelion lies within Mercury's orbit . The asteroid and its moon squannite are the closest double systems to the sun .

Discovery and naming

Moshup was discovered on May 20, 1999 during LINEAR sky surveillance in Socorro, New Mexico . The planetoid was given the provisional designation 1999 week 4 and on September 10, 2003, the IAU received the minor planet number 66391 .

The name "Moshup" was suggested, derived from the mythology of the Mohegan people . Moshup was a giant who lived in the coastal New England areas . On August 27, 2019, the name was confirmed by the IAU.

After his discovery, Moshup could be identified on photos going back to May 29, 1998 and thus his orbit calculated more precisely. Since then, the planetoid has been observed through various earth-based telescopes such as the Very Large Telescope . In September 2019 there were 3927 observations over a period of 22 years. (As of October 15, 2019)

Track properties

Orbit

Moshup orbits the sun in a prograde , strongly elliptical orbit between 29,905,000 km (0.1999  AU ) and 162,237,000 km (1.0844 AU) from its center. The orbit eccentricity is 0.689, the orbit is inclined by 38.88 ° in relation to the ecliptic .

The orbital period of Moshup is 0.51 years.

Risk to the earth

Moshup approached Earth to within 5 million kilometers in May 2001 . During this period, a radar survey was carried out with the Arecibo telescope . A second approximation, also to 5 million kilometers, took place in May 2019. The next approximation will take place in another 17 years, in 2036.

According to the orbit analyzes, based on the current state of knowledge, a collision with the earth in the next 1000 years can be ruled out. Moshup, however, rotates very quickly around its axis at 2.765 hours, so that it can be accelerated just a little further - e.g. B. by the YORP effect - could become unstable and break. Should this occur, the potential danger for the earth would increase greatly.

Physical Properties

size

(66391) Moshup and Squannite.

The observations made so far indicate an irregularly shaped, elongated body; the most precise determination of the diameter ( geometric mean ) is 1.317 ± 0.04 km. With regard to the exact dimensions, the most precise value is 1.532 × 1.495 × 1.347 km.

Based on this mean diameter, the surface area is approximately 5.5 km 2 . The absolute magnitude of the asteroid is 16.5 and 16.6, respectively

rotation

Moshup rotates once on its axis every 2 hours and 45.9 minutes. It follows that the asteroid 1631.9 in a Moshup-year own twists performs.

Moshup and Squannite based on radar observations.

moon

Moshup's squannite (provisional designation S / 2001 (66391) 1 ) is a small moon that orbits the asteroid at a distance of 2.55 kilometers with a period of 17.42 hours. Squannite has dimensions of 0.57 × 0.46 × 0.35 km and a mass of 0.13 ± 0.02 × 10 12 kg. The determination of the density, however, still has great uncertainties, so that so far only a value between 2.2 and 3.6 g / cm 3 can be given.

The Moshup system at a glance:

Components Physical parameters Path parameters discovery
Surname Throughput
diameter
(km) 		Relative
size
% 		Mass
(kg) 		Major
semi-axis
(km) 		Orbital time
(d) 		eccentricity Inclination
to Moshup's
equator 		Date of discovery
Date of publication
(66391) Moshup 1.317 100.00 2.35 · 10 12 - - - - May 20, 1999
1999
Squannite
(Moshup I) 		0.451 34.1 1.35 · 10 11 2.548 0.7259 0.0004 156.1 May 21, 2001
May 23, 2001

See also

literature

  • Steven J. Ostro et al .: Radar Imaging of Binary Near-Earth Asteroid (66391) 1999 KW4; American Astronomical Society, DPS meeting # 38, # 65.02; 09/2006
  • Daniel J. Scheeres et al .: Dynamical Configuration of Binary Near-Earth Asteroid (66391) 1999 KW4; American Astronomical Society, DPS meeting # 38, # 65.03; 09/2006

Web links

Commons : 66391 Moshup  - Collection of Images

Individual evidence

  1. ↑ v ≈ π * a / period (1 + sqrt (1-e²))
  2. ↑ (66391) Moshup in the Small-Body Database of the Jet Propulsion Laboratory (English). Template: JPL Small-Body Database Browser / Maintenance / AltRetrieved October 15, 2019.
  3. ↑ (66391) Moshup at the IAU Minor Planet Center (English)
  4. ↑ https://www.scinexx.de/news/kosmos/doppel-asteroid-passiert-die-erde/
  5. ↑ https://www.20min.ch/wissen/news/story/Spezielles-Rendez-vous--Doppel-Asteroid-sehen-an-Erde-vorbei-19388682
  6. ↑ https://www.merkur.de/welt/asteroid-fliegt-um-1-05-uhr-knapp-an-erde-vorbei-potentielle-bedrohung-12320969.html
  7. ↑ LCDB Data for (66391)
  8. ↑ AstDyS. Universita di Pisa, accessed November 1, 2019 .
  9. ↑ Ostro, SJ et al., Radar Imaging of Binary Near-Earth Asteroid (66391) 1999 KW 4 , Science, 2006, Vol. 314, pp. 1276-1280