The main body, Ida, is a part of the Koronis family of asteroids found between the orbits of Mars and Jupiter. It is thought that all of these types of asteroids were created by some cataclysmic event which blew apart a larger body, perhaps around 200 to 300 km in diameter. This event (which is theoretical) would also have taken place long after the formation of the solar system and so in celestial terms it is considered a “recent” event. That means had this event not taken place we would have had at least one more dwarf planet in our solar system than we do today.

The smaller asteroid, or moon of Ida, is named Gaspra and was only discovered as Galileo flew by and relayed the images back to Earth. The flybys were planned as “extras” for the Galileo mission as they were for the most part “on the way” to its central mission to the Jupiter system. It is thought that Gaspra has a nearly identical composition to Ida and is therefore not thought to be a “captured” moon, but rather one formed somehow from itslef either from a later impact or from the destruction of the originating Koronis body.

This entry was posted on Saturday, December 9th, 2006 at 3:49 pm and is filed under Asteroids. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.