Before the invention of digital cameras in the 1990's, and for more than 120 years before that, astronomers put in several million telescope hours photographing the night sky - measuring star brightnesses, detecting comets, planets, nebulae, mapping our Galaxy, and building the foundations of our understanding of our Universe! All of this raw beauty, and secrets yet to be discovered, are held as l
argely unexplored photographic images on thin, fragile pieces of glass. The Astronomical Photographic Data Archive (APDA) contains >40 of these astronomical photographic plate collections from institutions and observatories in North America totaling more than 220,000 plates dating back to 1898 and is growing larger every year. The goal of ALP is to make APDA a resource harnessed by present and future generations of astronomers, bringing 20th century analog astronomy into the 21st century digital world. We envision astronomers, students, and the general public benefiting from ALP as new research is made possible by access to the abundance of rich, high quality astronomical data now available only in analog form. Digitizing the plates is the only way to forever preserve these 1,000 terabytes of data acquired and left as a legacy to us by our greatest scientists studying the night sky, and giving future explorers a time machine to the past night sky.
