The US space agency Nasa is sponsoring a university course on how to talk to aliens.

English students at the University of Wyoming are being encouraged to consider the possibility that humanity might one day make contact with aliens and then not know what to say.

"Interstellar Message Composition", a creative writing class, is believed to be the first of its kind to engage writers in a potential cosmic conversation, say its founders.

"We've thought a lot about how we might communicate with other worlds, but we haven't thought much about what we'd actually say," Prof Jeffrey Lockwood, the course leader, told ABC News.

The course, currently being taken by 11 students, is partly financed by Nasa's Wyoming Space Grant Consortium, which sponsors educational and research projects in the state that support the agency's missions.

Among questions tackled in Prof Lockwood's class is how aliens might communicate, whether they would be able to translate human language, and whether they would be able to see or hear.

One student, Dixie Thoman, created a poem about menstruation with syllables arranged in a mathematically harmonious order, known as the Fibonacci sequence.

Recordings of the Brandenburg Concerto and Johnny B Goode are among those that have been beamed into space over the years in an attempt to provoke an extraterrestrial response.

The course is being advised by Douglas Vakoch, director of interstellar message composition for the Search For Extraterrestrial Intelligence Institute in California.

"It could be tomorrow that we'll need to be ready to decide if we reply [to aliens]," he said. "It's really critical to have people start thinking about it and it makes sense to start with writers. These are people who are really trying to express the human condition."