Astronomy Picture of the Day (APOD) began on June 16, 1995 with the computer generated image shown here of Earth as a hypothetical neutron star. Each day since, the two astronomers who create APOD have devised a learn node: a webpage that focuses on a small subject interfaced by an image, and that links out into the Internet to related topics. Pushing, as learnodes.com does, for something called “learn nodes” is not an effort to invent something new. A learn node captures content for learning by exploiting the natural powers of the open Internet. The robust, 13-year history of APOD illustrates the validity and educational power of basing learning content in nodes.
Using the network node is the first key to the effectiveness in creating superior knowledge content in the open Internet. The second key is the creation of the nodes by people who are experts in their subject. The About page of APOD explains:
Astronomy Picture of the Day (APOD) is originated, written, coordinated, and edited since 1995 by Robert Nemiroff and Jerry Bonnell. The APOD archive contains the largest collection of annotated astronomical images on the internet.
In real life, Bob and Jerry are two professional astronomers who spend most of their time researching the universe. Bob is a professor at Michigan Technological University in Houghton, Michigan, USA, while Jerry is a scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland USA.