Astronomy Picture of the Day . NGC 6210: The Turtle in Space Planetary Nebula . ... Credit: R. Rubin (NASA/Ames) et al., WFPC2 , HST , NASA Explanation: A Turtle in Space? Planetary nebula NGC 6210 may look like a giant space turtle, but it is actually much more massive and violent. ... NGC 6210 was investigated with the Hubble Space Telescope because it showed evidence of unusual relative abundances of nebular gas. ... Publications with keywords: planetary nebula . ... The Medusa Nebula . ...