In winter the fog sometimes does not dissolve the whole day. In space, planetary nebulae usually exist for many millennia, because they are star shells that have been ejected by their stars at the end of their lifetime.
In the case of the Stingray Nebula, which was first catalogued in 1976 and is located 18,000 light years from Earth, this seems to be an exception. Images of the system taken by the Hubble Space Telescope in 2016 show a nebula that has drastically lost brightness and changed shape compared to Hubble images from 1996. Light blue gas shells near the center of the nebula have all but disappeared, and the wavy edges that gave this nebula its aquatic name have practically disappeared.