Final answer:
The irony of the statement "There's no place like home" lies in the contrast between its usual connotation of safety and comfort and the emotional disconnect and unwelcoming situations the characters find themselves in.
Step-by-step explanation:
The statement "There's no place like home" is ironic in the context of the surprising news because it usually conveys comfort and safety, yet the characters are finding themselves in situations where home is not entirely a sanctuary or it is associated with uncomfortable revelations. For instance, Marjorie is implied to have learned that Bernice, whom she does not consider a friend or intimate, has to leave due to her own actions.
This creates a bitter taste to the phrase as Marjorie is paying to get rid of her cousin, making 'home' not a welcoming place for Bernice. Moreover, the second passage referencing The Wizard of Oz connects the saying to a sense of belonging and survival, amplified by the discussion of alien environments within our solar system, suggesting a contrast to the safety implied by the phrase when considering the vast and hostile universe.