Denmark the 22 proposals have been agreed upon by a parliamentary majority. Denmark shares strong cultural and historic ties with its Scandinavian neighbours Sweden and Norway. It has historically been one of the most socially progressive cultures in the world. In 1969, Denmark was the first country to legalise pornography, and in 2012, Denmark replaced its "registered partnership" laws, which it had been the first country to introduce in 1989, with gender-neutral marriage. Modesty and social equality are important parts of Danish culture. The astronomical discoveries of Tycho Brahe (1546–1601), Ludwig A. Colding's (1815–88) neglected articulation of the principle of conservation
Lunar and Planetary Institute limited collection development extending into the secondary support field of computer science remote sensing. There is an ongoing effort to scan and make available to the scientific community and the general public a number of out-of-print planetary science books, NASA documents and images, and related works. (These publications are copyright-free or made available with permission.) This collection is a NASA Regional Planetary Image Facility (RPIF) and includes photographs, maps, and other data from planetary missions including Apollo, Lunar Orbiter, Clementine, Mars Pathfinder, Voyager 1, Voyager 2, Magellan, Galileo and Mars Global Surveyor. The library maintains a weblog called What's New