Twitter - for over 13s - is being used to make contact with astronauts
The American space agency NASA is helping space enthusiasts chat to astronauts aboard the International Space Station - using Twitter.
Unlike a normal blogging service, all the messages have to have less than 140 letters and they are known as Tweets.
But who would you want to chat to if you could tweet anybody? School Reporters from Cardinal Newman Catholic School in Hove, East Sussex, gave their views.
Life in the slums
Becky, 14, said: "I would twitter Rubina Ali from the film Slumdog Millionaire; she played Latica. I would like to tweet her because I want to know what is happening to her now.
"I want to find out her perspective of living in the slums because we've heard adults who live there talk about it, we've seen images and clips ourselves about what's it like there, but we've never actually heard a child's perspective of it.
"Her life has been completely turned around, from being in the film. The sort of questions I would like to ask her are: How did she feel when Danny Boyle asked her to play the part in this film? What was it like? How did they treat her, from being a child in the slums to being a professional actress?
"I want to ask her how she lived beforehand and was she actually happy living in the slums? Watching the film, I found that being a child and living in the slums was one big adventure; it's sometimes happy and sometimes sad."
"I'd like to ask: What's going to happen to her in the future? Is she going to stay in the slums with her family or is she going to move away?"
Beyond the grave
Patrick, 13, said: "I'd tweet Michael Jackson because I'm a great fan of his and I'd like to find out about his life, not just the music but the controversial side of it.
Ella,13, said: "I'd tweet Barack Obama's two daughters because you don't really hear much about them and they are children like us, but they live completely different lives.
"Their dad is the first black president and they've been catapulted into a really surreal lifestyle. It must be really hard because everything they do is being watched and observed by people."
"They have to carry the reputation of their dad and everything they do goes back to him. As they're kids, it must be quite hard to do everything right. He must go away lots and they'll probably miss him loads.
"I would like to ask them questions such as: How do you feel living in the White House? What it's like, because you know so much about it? What has changed in your lives? Is there ever a time when you want your lives to go back to normal? Do you worry about your dad's safety? How do you feel about him being president?"
Louis said: "I would tweet Steve Backshall; he's a man that has a career as an explorer and a mountaineer. He's on TV where he presents a children's show called Deadly 60, where he finds some of the most deadly animals in the world.
"I think that he's so exciting and he really inspires me with what he does. Just to get a glimpse of something like that in a tweet would be a great insight.
"I'd like to ask him things like: Was he ever scared about things he was challenged to do? Growing up, did anything inspire him to pursue the career that he leads now?
"When he led the expedition into Mount Bosavi, one of then extinct mountains, I think that was really brave of him and exciting as he was the first person to do that - that must have been really exciting for him."
Some of the students' comments were used in the BBC World News for Children bulletin which is broadcast Monday to Friday on the
website and available between 1300 and 1700 GMT on the
website. It can be
for free and
are also available.