A quasi-satellite (from lat. Quas (i) “like”, “something like”) is an object located in the orbital resonance 1: 1 with the planet , which allows it to remain near the planet for many orbital periods.
The period of revolution of the quasisatellite around the Sun corresponds exactly to the period of revolution of the planet, however, the quasisatellite has a different eccentricity of the orbit, usually exceeding the eccentricity of the orbit of the planet. With respect to the planet, the quasi-satellite slowly moves along an elongated path in the direction opposite to the movement of the planet.
Unlike a real satellite , the quasi- satellite ’s orbit is outside the Hill sphere and is therefore unstable. After some time, the mutual motion of the planet and the quasi-satellite passes to other forms of orbital resonance, which leads to their divergence.
In other cases of 1: 1 orbital resonance, for example, for a horseshoe-shaped orbit around the Lagrange points, the object does not remain close to the planet for several revolutions around the star. Objects moving in an orbit in the form of a horseshoe can for a short time go into the orbits of quasisatellites [1] , because of which they can be mistaken for such. An example of such an object is 2002 AA 29 .
Examples
- Land
For 2002, three quasisatellites of the Earth were known: (3753) Cruitney , 2003 YN 107 and (164207) 2004 GU9 . These objects remain in the orbits of the quasisatellite from tens to hundreds of years [1] . In 2011, it became known about another asteroid from the Apollo group in a horseshoe-shaped orbit - 2010 SO16 [2] . In 2012, an asteroid with a diameter of 50 meters (367943) Duende was discovered, which is not only a quasi-satellite, but also flew on February 15, 2013 at a minimum distance from the center of the Earth: 27,000 km [3] . In 2016, they discovered a new natural quasisatellite of the Earth - the asteroid 2016 HO3 - which began to revolve around the Earth about a hundred years ago [4] .
- Venus
Venus also has a quasi-satellite, 2002 VE 68 . The orbit of this asteroid also crosses the orbits of Mercury and the Earth. It is assumed that he remains the “companion” of Venus for 7000 years and leaves it after 500 years [5] [6] .
- Other planets
Based on the simulation, it can be argued that Uranus and Neptune can have quasisatellites since the formation of the solar system (approximately 4.5 billion years) [7] . For Jupiter, the quasisatellite can remain for 10 million years, for Saturn for up to 10,000 years. Giant planets have so far discovered one quasi-satellite - (309239) 2007 RW 10 at Neptune.
- Artificial quasisatellites
In early 1989, the Soviet interplanetary spacecraft Phobos 2 entered the orbit of the quasi-satellite near Phobos , the satellite of Mars , with an average distance of 100 km to Phobos [8] . According to calculations, the device could remain in orbit for several months, but due to a failure of the control system, communication with it was lost.
See also
- Co-orbiting satellite
- Natural satellite
Notes
- ↑ 1 2 M. Connors et al. Discovery of an asteroid and quasi-satellite in an Earth-like horseshoe orbit (English) // Meteoritics & Planetary Science : journal. - 2002. - Vol. 37 . - P. 1435 .
- ↑ ITAR-TASS: Asteroid satellite 400 km in diameter discovered on Earth
- ↑ Russian astronomers have declared the quasisatellite 2012 DA14 safe , Lenta.ru, 02/28/2012
- ↑ Scientists have found a new satellite of the Earth - asteroid 2016 HO3 . RIA News. Date of treatment June 16, 2016.
- ↑ Asteroid 2002 VE68, a quasi-satellite of Venus
- ↑ Photometric observations of the quasisatellite of Venus (Inaccessible link) . Date of treatment December 13, 2010. Archived December 13, 2010.
- ↑ P. Wiegert and K. Innanen. The stability of quasi satellites in the outer solar system (English) // The Astronomical Journal : journal. - IOP Publishing , 2000. - Vol. 119 , no. 4 . - P. 1978-1984 . - DOI : 10.1086 / 301291 .
- ↑ http://www.federalspace.ru/Doc1Show.asp?DocID=16 (the orbit is erroneously called “quasi-synchronous” ( English quasi-synchronous )
Links
- Quasi-satellite Information Page
- Earth's New Traveling Companion: Quasi-Satellite Discovered
- Astronomy.com: A new “moon” for Earth
- Discovery of the first quasi-satellite of Venus - University of Turku news release (August 17th, 2004)