(419624) 2010 SO 16
Asteroid 2010 SO 16 |
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Properties of the orbit ( animation ) | |
Orbit type |
Near-Earth asteroid , Apollo-type horseshoe orbit to Earth |
Major semi-axis | 1.001 AU |
eccentricity | 0.0752 |
Perihelion - aphelion | 0.926 AU - 1.076 AU |
Inclination of the orbit plane | 14.5 ° |
Length of the ascending node | 40.5 ° |
Argument of the periapsis | 108 ° |
Time of passage of the perihelion | March 5, 2010 |
Sidereal period | 1.00 a |
Physical Properties | |
Medium diameter | 200-400 m |
Absolute brightness | 20.6 mag |
history | |
Explorer | WISE space telescope |
Date of discovery | 17th September 2010 |
Another name | MPO192619 |
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. |
(419624) 2010 SO 16 is an Apollo-type asteroid discovered in 2010 with the help of the WISE space telescope. Its inclination is 14.5 °, the absolute brightness 20.6. With a diameter of about 300 meters it is the largest known asteroid on a terrestrial horseshoe orbit runs, and overall the fourth Anm1 been discovered object of this type.
Special features of the railway
Due to its special orbit shape, SO 16 has practically the same distance to the sun in 2010 as the earth itself. It comes close to the earth to a maximum of 20 million km. This corresponds to about 50 times the distance to the moon, which is why there is no risk of collision. The opening angle 2 φ min , i.e. the gap in the horseshoe in which the earth is located, is 25 °. The duration of the cycle on the horseshoe is 350 years.
Track shape
Based on the existing path data were computer simulations performed possible paths. The eight main planets were also taken into account. The gravitational effect of the moon was taken into account as an additional earth mass. The calculations were made using the Radau method . Two calculations were made:
- The first was based on observations from WISE and ground-based telescopes, including Spacewatch II , over 62 days up to November 18, 2010,
- the second based on additional observations from Spacewatch II over 75 days until December 1, 2010.
Both simulations resulted in a horseshoe orbit. At the time of April 2011 the asteroid was near the turning point, which is behind the earth. By 2016, SO 16 will come close to Earth between 0.13 and 0.2 AU in 2010 . It will be observable in the evening sky for several decades.
A series of path variants was dynamically integrated to check the simulations. The calculations were also used to study the length of time the asteroid stayed on the horseshoe track. The following parameters were varied:
- major semi-axis a
- mean anomaly M
- Eccentricity e
- Argument of the pericenter ω
For a nine values were calculated in the range of the measurement inaccuracy 1- σ , for the other parameters three values each in the range 1.5- σ , so a total of 9 × 3 3 = 243 path variants. The calculations were carried out for a period of ± 100,000 years based on the present. In all cases there were horseshoes.
stability
In order to investigate the stability of the horseshoe train, further train variants were calculated. The major semi-axis was varied in the range of ± 4 σ . 35 variants each were calculated for the past and the future; So a total of 70 track variants. The integrations were calculated up to a period of 2 million years. The results of these calculations are shown in Table 1.
Length of stay in years |
number | Remarks |
---|---|---|
<200,000 | 4th | Shortest established residence time 120,000 years |
200,000-500,000 | 50 | |
> 500,000 | 16 | Of which 8> 1 million years and 2> 2 million years (end of integration) |
This means that the 2010 SO 16 runway is far more stable than other objects on similar runways that leave their horseshoe tracks after a few thousand years.
The asteroid has accompanied the earth for at least 250,000 years, and its origin may even go back to the early days of our solar system.
origin
Three possible origins were discussed. An origin from the main belt is considered unlikely because of the earth-like orbit, but it cannot be completely ruled out. The origin from the earth-moon system is just as unlikely, since the orbit would change several times within a few 100,000 years.
A third possibility is the origin on a kidney-shaped orbit near the L 4 or L 5 Lagrangian points of the asteroid-earth-sun system. SA Tabachnik and NW Evans showed in a publication in 2000 that objects on such orbits can survive 50 million years, provided the inclination i and eccentricity e have the correct values (for i : either 24 ° < i <34 ° or i < 16 °; for e : e ≈ 0.06). In the case of 2010 SO 16 , both sizes are in the appropriate ranges. Extrapolations over 5 billion years also showed that a small part of the asteroids could survive even such long periods on corresponding orbits.
On the other hand, it can be argued that the calculations by Tabachnik and Evans ignore the Jarkowski effect . 2010 SO 16 could hardly last longer than a few million years on a corresponding runway. However, a study on the stability of Mars Trojans in 2005 showed that the Jarkowski Effect does not necessarily destabilize large Trojans.
For a final decision, more information about size, spectral class and angular momentum would be necessary. 2010 SO 16 could also be a test object for the verification of the Jarkowski acceleration.
Web links
- (419624) 2010 SO16 in the Small-Body Database of the Jet Propulsion Laboratory (English).
- Rüdiger Vaas : Earth's secret companion . On: Wissenschaft.de on April 7, 2011, accessed on September 10, 2019.
- Astronomers Find Newly Discovered Asteroid is Earth's Companion (accessed April 30, 2011). With an animation of the orbit for the years 1960 to 2059 and a blinking animation of the asteroid. Then also:
- WISE Mission Spots 'Horseshoe' Asteroid (accessed April 30, 2011, 6:11 pm). Contains a picture with the highlighted version from 2011 SO 16 .
Remarks
Individual evidence
- ↑ a b c d e f g AA Christou, DJ Asher : A long ‐ lived horseshoe companion to the Earth . In: Monthly Notices of the Royal Astronomical Society . tape 414 , no. 4 , 2011, p. 2965–2969 , doi : 10.1111 / j.1365-2966.2011.18595.x ( academic.oup.com [PDF; 2.1 MB ]).
- ↑ a b c Rüdiger Vaas: Secret companion of the earth. In: Wissenschaft.de. April 7, 2011, accessed September 9, 2019 .
- ↑ Apostolos Christou, David Asher: (419624) 2010 SO16 in the Small-Body Database of the Jet Propulsion Laboratory (English).
- ↑ Asteroid 2010 SO16 is following Earth in its orbit around sun . EarthSky, April 6, 2011.
- ↑ Asteroid Stalks Earth in Weird Horseshoe-Shaped Orbit . SPACE.com, April 6, 2011.
- ↑ Astronomers Find Newly Discovered Asteroid is Earth's Companion ( Memento from May 14, 2011 in the Internet Archive ). Armagh Observatory, accessed April 30, 2011.
- ^ SA Tabachnik, NW Evans: Asteroids in the inner solar system - I. Existence . In: Monthly Notices of the Royal Astronomical Society . tape 319 , no. 1 , 2002, p. 63-79 , doi : 10.1046 / j.1365-8711.2000.03760.x .
- ^ H. Scholl, F. Marzari, P. Tricarico: Dynamics of Mars Trojans . In: Icarus . tape 175 , no. 2 , 2005, p. 397-408 , doi : 10.1016 / j.icarus.2005.01.018 .