... First discovered in 1986 and designated 1986 OT, this five kilometer rock was recently found to orbit the Sun while executing a strange dance with the Earth. ... Arp 220: Spirals in Collision . ... Arp 220 is the brightest object in the local universe. ... Arp 220 was cataloged as a peculiar galaxy in the 1960s. In the late 1980s, it was discovered to be an ultraluminous infrared galaxy and headed a list compiled from observations with the now-defunct IRAS satellite. ... Jupiter's Dry Spots . ...