(also written 2013 ND15) is an

asteroid An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ...

that is a temporary trojan of

Venus Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never fa ...

, the first known Venus trojan.

Discovery, orbit and physical properties

was discovered on 13 July 2013 by N. Primak, A. Schultz, T. Goggia and K. Chambers, observing for the Pan-STARRS project. As of September 2014, it has been observed 21 times with a data-arc span of 26 days. It is an Aten asteroid and its semi-major axis (0.7235 AU) is very similar to that of Venus but it has high eccentricity (0.6115) and small orbital inclination (4.794°). With an absolute magnitude of 24.1, it has a diameter in the range 40–100 m (for an assumed albedo range of 0.04-0.20).

Trojan dynamical state and orbital evolution

Animation of 2013 ND15 relative to Sun and Venus

has been identified as a Venus trojan following a

tadpole orbit In celestial mechanics, a horseshoe orbit is a type of co-orbital motion of a small orbiting body relative to a larger orbiting body. The osculating (instantaneous) orbital period of the smaller body remains very near that of the larger body, a ...

around Venus' Lagrangian point . Besides being a Venus

co-orbital In astronomy, a co-orbital configuration is a configuration of two or more astronomical objects (such as asteroids, moons, or planets) orbiting at the same, or very similar, distance from their primary, i.e. they are in a 1:1 mean-motion resonan ...

, this asteroid is also a Mercury crosser and an Earth crosser. exhibits resonant (or near-resonant) behavior with

Mercury Mercury commonly refers to: * Mercury (planet), the nearest planet to the Sun * Mercury (element), a metallic chemical element with the symbol Hg * Mercury (mythology), a Roman god Mercury or The Mercury may also refer to: Companies * Merc ...

, Venus and

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

. Its short-term dynamical evolution is different from that of the other three Venus co-orbitals, , , and .

Potentially hazardous asteroid

is not included in the

Minor Planet Center The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory. Function ...

list of potentially hazardous asteroids ( PHAs) because its absolute magnitude is greater than 22.0, even though it comes to within 0.05 AU of Earth periodically. It approached Earth at 0.077 AU on 21 June 2016.

Notes

* This is assuming an albedo of 0.20–0.04.

References

;Further reading
Understanding the Distribution of Near-Earth Asteroids
Bottke, W. F., Jedicke, R., Morbidelli, A., Petit, J.-M., Gladman, B. 2000, ''Science'', Vol. 288, Issue 5474, pp. 2190–2194.
A Numerical Survey of Transient Co-orbitals of the Terrestrial Planets
Christou, A. A. 2000, ''Icarus'', Vol. 144, Issue 1, pp. 1–20.
Debiased Orbital and Absolute Magnitude Distribution of the Near-Earth Objects
Bottke, W. F., Morbidelli, A., Jedicke, R., Petit, J.-M., Levison, H. F., Michel, P., Metcalfe, T. S. 2002, ''Icarus'', Vol. 156, Issue 2, pp. 399–433.
Transient co-orbital asteroids
Brasser, R., Innanen, K. A., Connors, M., Veillet, C., Wiegert, P., Mikkola, S., Chodas, P. W. 2004, ''Icarus'', Vol. 171, Issue 1, pp. 102–109.
The population of Near Earth Asteroids in coorbital motion with Venus
Morais, M. H. M., Morbidelli, A. 2006, ''Icarus'', Vol. 185, Issue 1, pp. 29–38.
Asteroid 2013 ND15: Trojan companion to Venus, PHA to the Earth
de la Fuente Marcos, C., de la Fuente Marcos, R. 2013, ''Monthly Notices of the Royal Astronomical Society'', Vol. 439, Issue 3, pp. 2970–2977.

External links