Four families of extremely young asteroids have been identified by researchers affiliated with São Paulo State University (UNESP) in Guaratinguetá, Brazil. An article on the discovery has been published in Monthly Notices of the Royal Astronomical Society.
"We identified the new families by means of numerical simulation using the backward integration method (BIM), which is much more precise than other methods for dating asteroid families. But BIM only works for really young families that are less than 20 million years old. Until recently, only eight families had been studied by this method. We now know 13, almost a third of which were identified by our group," said Valerio Carruba, a professor in UNESP's Mathematics Department.
Carruba - Research - Project - Families - Engineering
Carruba coordinated the research project on asteroid families conducted at the Engineering School of UNESP's campus in Guaratinguetá. The four families in question, all of which are less than 7 million years old, orbit between Mars and Jupiter as part of a grouping known as the Main Asteroid Belt.
The key dating parameters used were the longitudes of the pericenter and ascending node. For a planet, comet or asteroid moving around the Sun in an elliptical orbit, the pericenter is the point at which it comes closest to the Sun. The ascending node is the point at which the orbit crosses from the southern side of a reference plane, typically the ecliptic plane, to the northern side.
Family - Asteroids - Pericenters - Nodes - Family
"When an asteroid family is formed, all the asteroids' pericenters and ascending nodes are aligned, but as the family evolves, the alignment is lost owing to gravitational disturbances produced by planets and possibly by some massive asteroids," Carruba explained. "Based on current data, BIM lets you go back in time using numerical simulation to reconstruct the setting in which the parameters were aligned and thereby date the asteroid family."
In addition to the...
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