Make the questions indirect. Start with "They ask..."
1 Has anybody landed on Mars?
2 Is there life on Venus?
3 Willl people live on the Moon some
day?
4 Do astronauts often visit Space Flight Control center?
5 Are there any aliens out there?

1 They ask if anybody has landed on Mars2 They ask if there is life on Venus3 They ask if people will live on the Moon some day4 They ask if astronauts often visit Space Flight Control center5 They ask if there are any aliens out there