HELP ASAP!!

What is the theme to the following passages?

1. “The teacher said that she hoped all her students would pass with good grades.”

2. “The space travelers were traveling to the moon, when their spaceship suddenly ran out of fuel. They were all frightened to learn that they wouldn’t be able to return to Earth and could only land on the moon.”

3. “When the astronaut landed on the moon, he felt loneliness. Thinking there was no one else, he became a little forlorn, though the view of Earth was stunningly beautiful.”