Amanda Tapping, who co-stars with Richard Dean Anderson in the sci-fi series STARGATE SG-1 (Seven, Thursday 8:30 PM), is now a firm believer in UFOs.

Taking up where the film STARGATE left off, the series sees a military team from Earth reach distant planets by journeying through the mysterious stargate.

Her role as Captain Samantha Carter has convinced her of the existence of extra-terrestrials.

"I think it would be terribly egotistical of me to say, 'No there is not'." she said by phone from Los Angeles. "I don't believe we are the only intelligent race in this vast galaxy about which we only have a limited knowledge. I think, absolutely, that there has to be something else.

She also considers the mind-stretching sci-fi storylines of STARGATE SG-1 may not be as farfetched as first thought.

"The interesting thing about science fiction is so much of what we talk about is slowly becoming science fact," she said.

"I mean 60 years ago the thought of going to the moon was insane."

Playing an astrophysicist, Tapping has to learn mind-numbing scientific dialogue. "It can be very difficult to memorise," she said. "I went to the library to try to learn everything I could about astrophysics, which is not easy. But the only time it is really hard is when you have a scene with about 10 lines of technobabble."

Tapping finds sci-fi fans are phenomenally dedicated.

"I grew up with three brothers who were into it, but I was more a LITTLE HOUSE ON THE PRAIRIE girl," she said. "Now I am learning to appreciate the genre and understand it more. The beauty of working with sci-fi is that the possibilities are endless and you have the most loyal and wonderful fans in the world."