It has been running for three months but tonight Tom Hank's extraordinary lunar odyssey, From The Earth To The Moon (Pearl, 10.30pm) comes to a close.
It ends on a poetic note, fitting for the achievement of this television marathon. Le Voyage Dans La Lune contrasts one of the first visions of man's quest for the moon, portrayed in the early years of cinema by the French film-maker Georges Melies, with the most recent trip in 1972.
We are now well aware of executive producer Hank's enthusiasm for space adventure. The final episode sets out to explain why we and our children should share his interest despite the fact that the world's media and public so quickly lost interest after the first landing. To get there was a unique human achievement, it reminds us, symbolising our willingness and ability to overcome all difficulties.
Hanks the actor plays a minor role as the friend and collaborator of Melies, obliquely paying homage to the human imagination that made the impossible achievable within 70 years of his human canon story.
But we are also reminded of the many and varied obstacles to such ambitions. Melies' film did not earn him fame or fortune. The footage was, instead, stolen, copied and sold by none other than American science genius Thomas Edison. It is such quirky detail that has made this series much more than a gung ho story of America's conquest of space.
Two of the Apollo 17 astronauts, Gene Cernan (Daniel Hugh-Kelly) and Harrison Schmitt (Tom Amandes), feature more prominently tonight than they did in the media at the time. This series, at least, ensures them another place in history.
After so many weeks of From The Earth To The Moon, most of us will have sated the great or little interest we have in the lunar story. But Hong Kong television has not done with it yet. ATV is showing The Other Side Of The Moon (World, 10pm), a documentary made a decade ago to mark the 20th anniversary of the first landing. World is showing it in two parts.
Eight of the 12 astronauts who stepped on the moon share their experiences and the effect the journey has had on their lives. They do not include the biggest names such as the reclusive Neil Armstrong, nor any of those from Apollo 17.
If the lunar missions were a product of Cold War rivalry between the United States and the Soviet Union, the natural history series Realms Of The Russian Bear (World, 9pm) is one of the happier outcomes of Glasnost. The BBC's Natural History Unit enjoyed unprecedented access to make this remarkable series, spending three years exploring the wilderness of the former Soviet Union, from the Caspian Sea to Siberia to the Celestial Mountains bordering China.
The first of the six beautifully filmed episodes, Green Jewel Of The Caspian, focuses on the Volga Delta, Russia's oldest nature reserve and an abundant source of that favourite delicacy, caviar.