This teen sci-fi romance features sweet lead performances in an original concept – what would happen if a teenage human boy living on a NASA project on Mars met an earthbound girl and fell in love? – but a few plot holes require gravity-defying suspension of disbelief. Definitely romantic, though.

Long-distance relationships add a burden to plenty of people, but imagine the teenage angst that would arise if a human boy living on Mars and an earthbound girl fell in love. That’s the sweet and often intriguing premise of the new sci-fi romance “The Space Between Us,” a movie that might become a teen-movie favorite unfortunately marred by a casual attitude towards teen sex in a key scene.

“Space” starts by seeming to follow the story of a female astronaut preparing for a mission to Mars a decade or so in the future. But in a sharp twist early in the movie, she finds that she is pregnant and NASA fears sending her back to earth for the pregnancy term and delivery because it is feared that space travel might harm or kill the baby.

Yet she dies after delivering her son Gardner (Asa Butterfield), who winds up being raised by the rest of the astronauts, particularly mother-figure Kendra (Carla Gugino). It is feared Gardner can never travel through space since his molecular structure has been affected by the differing gravitational pull and other biological adaptations he’s made to living on Mars, but he is lonely and as a teen, winds up communicating online with an earthbound girl named Tulsa (Britt Robertson).

Tulsa is a foster child prone to mischief, and eventually the two fall for each other, with Gardner winning the right to come to Earth and meet her over Mars mission leader Nathaniel Shepherd’s (Gary Oldman) concerns. When the two meet, they are instantly in love, with Gardner touchingly and comically adjusting to life on earth through her guidance.

But Gardner is too curious for his own good about his past, and wants to meet the father he has never known. Together, he and Tulsa run away from their supervisors using a couple of stolen cars, and hit the road to find his father – while not realizing how much the earth’s atmosphere is starting to harm him.

“The Space Between Us” is a fun and involving road-trip movie, with sweet young lead actor performances by Robertson and Butterfield that will win audiences over. Foul language is kept rather minimal, but there’s a brief scene that makes it obvious the young couple just had sex together in obviously illicit fashion.

This is kind of a red flag for teens, but most adults shouldn’t be affected, and every other scene of the movie is good clean fun with a compelling premise on a couple of levels. Aside from that, the kids steal a couple of cars while on the run, and use some lighthearted deception to stay one step ahead of the authorities. These factors are merely part of the entertaining storyline and unlikely to inspire bad behavior.

Screenwriter Allan Loeb has crafted a fun story overall, but there are several key moments in which there are somewhat unbelievable leaps of logic or plot holes. Audiences will likely like the actors and unique storyline enough to go with those moments, however, and overall, “The Space Between Us” is largely inoffensive