If you think your tweets are inventive and interesting, there may be a way to send them further than they have ever been before.
Nasa is currently collecting tweets and photos posted with the hashtag #MessageToVoyager.
One is to be picked out to be sent up to the Voyager, which is the furthest man-made object from earth.
Suzy Dodd, the Voyager Interstellar Mission project manager, told CNN: "Our planet may be long gone and the [Voyager] will still be travelling through space and our galaxy.
"What would you like to add [to the time capsule message]? What well wishes do you have for our interstellar ambassador?"
The reason for this is to celebrate the Voyager's 40th year in space. Anyone can send in an entry until August 15, then on August 23 public voting will begin.
Nasa will send the message to space on September 5.
The craft is the first ever to fly past Jupiter, Saturn, Uranus and Neptune and is currently the oldest-running space mission.