Kirkwood gaps are gaps or dips in the distribution of
main belt asteroids with semi-major axis(or equivalently their orbital period), as seen in the .
For example, there are very few asteroids with semimajor axis near 2.50 AU, period 3.95 years, which would make three orbits for each orbit of Jupiter (hence, called the 3:1 orbital resonance). Other orbital resonances correspond to orbital periods whose lengths are simple fractions of Jupiter's. The weaker resonances lead only to a depletion of asteroids, while spikes in the histogram are often due to the presence of a prominent
The gaps were first noticed in
1857by Daniel Kirkwood, who also correctly explained their origin in the orbital resonances with Jupiter.
More recently, a relatively small number of asteroids have been found to possess high eccentricity orbits which do lie within the Kirkwood gaps. Examples include the
Alinda familyand the Griqua family. These orbits slowly increase their eccentricity on a timescale of tens of millions of years, and will eventually break out of the resonance due to close encounters with a major planet.
The most prominent Kirkwood gaps (see diagram) are located at mean orbital radii of:
*2.06 AU (4:1 resonance)
*2.5 AU (3:1 resonance), home to the
Alinda familyof asteroids
*2.82 AU (5:2 resonance)
*2.95 AU (7:3 resonance)
*3.27 AU (2:1 resonance), home to the
Griqua familyof asteroids
Weaker and/or narrower gaps are also found at:
*1.9 AU (9:2 resonance)
*2.25 AU (7:2 resonance)
*2.33 AU (10:3 resonance)
*2.71 AU (8:3 resonance)
*3.03 AU (9:4 resonance)
*3.075 AU (11:5 resonance)
*3.47 AU (11:6 resonance)
*3.7 AU (5:3 resonance)
* [http://scienceworld.wolfram.com/astronomy/KirkwoodGaps.html Article on Kirkwood gaps at Wolfram's] scienceworld
* [http://www.physics.udel.edu/~jim/solarsystem/Motion%20of%20an%20asteroid.htm A method to create a short-term simulation] .
Wikimedia Foundation. 2010.
Look at other dictionaries:
Kirkwood — is the name of some places in the United States of America: *Kirkwood, California **Kirkwood Mountain Resort *Kirkwood, Delaware *Kirkwood (Atlanta), Georgia *Kirkwood, Illinois *Kirkwood, Missouri *Kirkwood, New Jersey *Kirkwood, New York… … Wikipedia
Pa Tio Tio Gap — (coord|76|25|S|161|57|E|) is a glacier filled gap at 1,000 m. It trends east west between Robertson Massif and Endeavour Massif in Kirkwood Range, Victoria Land. Pa Tio Tio is a Maori word meaning frozen over … Wikipedia
Asteroid belt — For the album by Velvet Chain, see Asteroid Belt (album). The asteroid belt (shown in white) is located between the orbits of Mars and Jupiter. The asteroid belt is the region of the Solar System located roughly between the orbits of the planets… … Wikipedia
Hungaria family — The Hungaria asteroids are a group of asteroids in the main belt that orbit the Sun between 1.78 and 2.00 AU. The asteroids typically have a low eccentricity (below 0.18) and an inclination of 16 to 34 degrees. [… … Wikipedia
Groups of minor planets — An asteroid group or minor planet group is a population of minor planets that have a share broadly similar orbits. Members are generally unrelated to each other, unlike in an asteroid family, which often results from the break up of a single… … Wikipedia
celestial mechanics — the branch of astronomy that deals with the application of the laws of dynamics and Newton s law of gravitation to the motions of heavenly bodies. [1815 25] * * * Branch of astronomy that deals with the mathematical theory of the motions of… … Universalium
Manifold: Space — … Wikipedia
Jack Wisdom — is a Professor of Planetary Sciences at the Massachusetts Institute of Technology. He received his Ph.D from Caltech in 1981. His research interests are the dynamics of the Solar System.Wisdom s 1981 dissertation demonstrated for the first time… … Wikipedia
List of Indiana University (Bloomington) people — This is a list of notable current and former faculty members, alumni, and non graduating attendees of Indiana University (Bloomington) in Bloomington, Indiana.University Presidents* Andrew Wylie * Alfred Ryors * William Mitchel Daily * John Hiram … Wikipedia
Near-Earth asteroid — Near Earth asteroids (NEAs) are asteroids whose orbits are close to Earth s orbit. All near Earth asteroids spend part of their orbits between 0.983 and 1.3 astronomical units away from the Sun. Some near Earth asteroids orbits intersect Earth s… … Wikipedia