Astronomy Picture of the Day . Tail Wags of Comet Ikeya Zhang . ... As Comet Ikeya-Zhang approached the Sun two months ago, it developed a complex blue ion tail. ... While exploring the inner edge of the Helix Nebula with the Hubble Space Telescope's Wide Field Planetary Camera 2, astronomers were able to produce this striking image - rich in details of an exotic environment. ... Trailing Planets . ... While the massive stone structure dates from around 2000 B.C. Sunspot Loops in Ultraviolet . ...