Don't doubt sci-fi has a place in history. Two classic sci-fi films, Back to the Future (Robert Zemeckis, 1985) and Close Encounters of the Third Kind (Steven Spielberg, 1977), are among the 25 films selected this year to be preserved by the Library of Congress National Film Registry, with the intent that they are available for future generations to enjoy.

The announcement by the Librarian of Congress notes that "culturally, historically or aesthetically" significant films from many eras and genres are selected in the annual effort to choose specific films to be guarded against deterioration. Nearly 500 films have been chosen for physical protection since the establishment of the Registry in 1992.

"Even as Americans fill the movie theaters to see the latest releases, few are aware that up to half the films produced in this country before 1950 -- and as much as 90 percent of those made before 1920 -- are lost forever," said the Librarian, James H. Billington. Early film stock was recycled for the silver nitrate content, and any film – unless very carefully stored in environmentally controlled conditions – will break down in mere decades. Even most digital media are not designed for generations.

The loss of films always makes me think of the otherwise forgettable Reign of Fire (Rob Bowman, 2002), set in a dragon-destroyed post-apocalyptic world – leading to a funny scene where adults, who remember the before-time, act out the "I am your father" scene from Empire Strikes Back, to the scandalization of watching children. Someday all our perishable media will fail, and the first centuries of film will be preserved, if at all, only second and third hand – much like Beowulf (the book) is almost the sole lengthy survivor of pre-Norman Anglo-Saxon literature.

The complete list of 2007 films is: Back to the Future (1985), Bullitt (1968), Close Encounters of the Third Kind (1977), Dance, Girl, Dance (1940), Dances With Wolves (1990), Days of Heaven (1978), Glimpse of the Garden (1957), Grand Hotel (1932), The House I Live In (1945), In a Lonely Place (1950), The Man Who Shot Liberty Valance (1962), Mighty Like a Moose (1926), The Naked City (1948), Now, Voyager (1942), Oklahoma! (1955), Our Day (1938), Peege (1972), The Sex Life of the Polyp (1928), The Strong Man (1926), Three Little Pigs (1933), Tol'able David (1921), Tom, Tom the Piper's Son (1969-71), 12 Angry Men (1957), The Women (1939), and Wuthering Heights (1939). More on the individual films here.

Previous genre selections include 2001: A Space Odyssey (1968), Alien (1979), Blade Runner (1982 [but which version?]), Cat People (1942), The Day the Earth Stood Still (1951), E.T. the Extra-Terrestrial (1982), Flash Gordon serial (1936), Frankenstein (1931), Groundhog Day (1993), Invasion of the Body-Snatchers (1951), Planet of the Apes (1968), Raiders of the Lost Ark (1981), Star Wars (1977), The Thing from Another World (1951), and The Wizard of Oz (1939).

A full list is here. While sci-fi is represented fairly proportionately, few fantasy films have been selected so far. Many landmark films are still absent from the list, including Superman (1979), The Iron Giant (1999), and so on. (What do you think is missing? Add your suggestion in the Comments.)

One film I'm especially glad is included: One Froggy Evening (1956). If that were the only twentieth-century film to survive for posterity, I could almost live with that. Almost.