Origin
Ida originated in the breakup of the roughly 120 km (75 mi) diameter Koronis parent body. The progenitor asteroid had partially differentiated, with heavier metals migrating to the core. Ida carried away insignificant amounts of this core material. It is uncertain how long ago the disruption event occurred. According to an analysis of Ida's cratering processes, its surface is more than a billion years old. However, this is inconsistent with the estimated age of the Ida–Dactyl system of less than 100 million years; it is unlikely that Dactyl, due to its small size, could have escaped being destroyed in a major collision for longer. The difference in age estimates may be explained by an increased rate of cratering from the debris of the Koronis parent body's destruction.
Read more about this topic: 243 Ida
Famous quotes containing the word origin:
“Though I do not believe that a plant will spring up where no seed has been, I have great faith in a seed,—a, to me, equally mysterious origin for it.”
—Henry David Thoreau (1817–1862)
“All good poetry is the spontaneous overflow of powerful feelings: it takes its origin from emotion recollected in tranquillity.”
—William Wordsworth (1770–1850)
“The essence of morality is a questioning about morality; and the decisive move of human life is to use ceaselessly all light to look for the origin of the opposition between good and evil.”
—Georges Bataille (1897–1962)