The symbolic meaning of the Hail Mary
Hail Mary is symbolically used to represent holiness and humanity. The entire crew in Project Hail Mary is selfless. For instance, every crew member knows that no one will return alive, but they are determined to reach the solar system to stop the alien that is about the destroy the solar system. The destruction of the solar system means the earth will become extinct.
The symbolism of sacrifice
Ryland Grace is a symbolic character who represents sacrifice. When the United Nations request Ryland to aid in preventing the extinction of the earth, he gladly accepts despite the dangerous nature of his assignment. Ryland must travel to space to neutralize an alien attacking the solar system, which endangers the whole earth. Ryland knows that he will not come back alive if he travels to space. Therefore, despite it being a suicide mission, Ryland accepts to carry out the assignment and sacrifice his life for the sake of saving humanity.
Tau Ceti star
The author symbolically uses tau Ceti star to represent science fiction. The alien eating up the solar system is a fictionalized creature, and the author tries to imagine the impact of the sun's destruction on earth. Therefore, the symbolism of science fiction in this book enlightens readers that the world is possibly becoming extinct if people do not take care of the environment and the entire ecosystem.
Taumoeba as a symbol of redemption
The author figuratively uses Taumoeba to symbolize redemption. After staying in space for some time, looking for a solution that can neutralize the alien attacking the solar system, Grace discovers that Taumoeba is the cure. With the help of Rocky and Astrophage, Grace manages to save the earth.