Astronomy Picture of the Day . NGC 7009: The Saturn Nebula . ... The above picture, taken in April 1996 and released last week, allows a better understanding of the mysterious process that transformed a low-mass star into a white dwarf star. ... Pluto: The Frozen Planet . ... Pluto is usually the most distant planet from the Sun but because of its elliptic orbit Pluto crossed inside of Neptune's orbit in 1979 and will cross back out again in 1999. Keck: The Largest Optical Telescopes . ...