Discovered in 1866, main belt asteroid [
http://www.nineplan…] 87 Sylvia lies 3.5 AU from the Sun, between the orbits of Mars and Jupiter. Also shown in recent years to be one in a growing list of double asteroids [
http://antwrp.gsfc.…], new observations during August and October 2004 made at the Paranal [
http://antwrp.gsfc.…] Observatory convincingly demonstrate that 87 Sylvia in fact has two moonlets - the first known triple asteroid system [
http://www.eso.org/…pr-21-05.html ]. At the center of this composite of the image data, potato-shaped 87 Sylvia itself is about 380 kilometers wide. The data show [
http://www.obspm.fr…] inner moon, Remus, orbiting Sylvia at a distance of about 710 kilometers once every 33 hours, while outer moon Romulus orbits at 1360 kilometers in 87.6 hours. Tiny Remus and Romulus are 7 and 18 kilometers across respectively. Because 87 Sylvia was named after Rhea Silvia [
http://www.pantheon…], the mythical mother of the founders of Rome, the discoverers [
http://www.berkeley…10_sylvia.shtml ] proposed Romulus and Remus as fitting names [
http://www.eso.org/…pr-21-05_p2.html ] for the two moonlets. The triple system is thought to be the not uncommon result of collisions producing low density, rubble pile [
http://www.boulder.…] asteroids that are loose aggregations of debris.
Explanation
Discovered in 1866, main belt asteroid [
http://www.nineplan…] 87 Sylvia lies 3.5 AU from the Sun, between the orbits of Mars and Jupiter. Also shown in recent years to be one in a growing list of double asteroids [
http://antwrp.gsfc.…], new observations during August and October 2004 made at the Paranal [
http://antwrp.gsfc.…] Observatory convincingly demonstrate that 87 Sylvia in fact has two moonlets - the first known triple asteroid system [
http://www.eso.org/…pr-21-05.html ]. At the center of this composite of the image data, potato-shaped 87 Sylvia itself is about 380 kilometers wide. The data show [
http://www.obspm.fr…] inner moon, Remus, orbiting Sylvia at a distance of about 710 kilometers once every 33 hours, while outer moon Romulus orbits at 1360 kilometers in 87.6 hours. Tiny Remus and Romulus are 7 and 18 kilometers across respectively. Because 87 Sylvia was named after Rhea Silvia [
http://www.pantheon…], the mythical mother of the founders of Rome, the discoverers [
http://www.berkeley…10_sylvia.shtml ] proposed Romulus and Remus as fitting names [
http://www.eso.org/…pr-21-05_p2.html ] for the two moonlets. The triple system is thought to be the not uncommon result of collisions producing low density, rubble pile [
http://www.boulder.…] asteroids that are loose aggregations of debris.
Explanation
