The Shark Nebula . ... Credit Copyright: Maurice Toet Explanation: There is no sea on Earth large enough to contain the Shark nebula. This predator apparition poses us no danger, though, as it is composed only of interstellar gas and dust . ... After being expelled with gas and gravitationally recondensing, massive stars may carve intricate structures into their birth cloud using their high energy light and fast stellar wind s as sculpting tools. ... NASA Official: Jay Norris. ...