More co-orbiters for Neptune

ome astronomers think that Neptune (pictured) can no longer capture objects whose orbits around the Sun are similar to its own. But Carlos and Raúl de la Fuente Marcos at the Complutense University of Madrid in Spain, have discovered that four objects originally classified as minor planets are actually co-orbiters that joined Neptune's orbit as recently as 50,000 years ago.

The work brings to 14 the number of objects that, like Neptune, orbit the Sun every 165 years. The four latest objects are not in the plane of the Solar System and follow eccentric paths. One is likely to diverge from its current path just 2,000 years from now.