Prisoners of the Sun: Part 2 - S3-E6
Continuity mistake: When Tintin climbs up the cliff to rescue Snowy from the condor's nest, he is carrying a rope over his right shoulder, but from a much further away angle, the rope is suddenly placed over his left shoulder. (00:26:10)
Answer: According to Wikipedia, he is described as being a youth anywhere from 14 - 19 years old. There is no specific age.
raywest ★