What optical device is the Dutch scientist, after whom the lunar crater Jansen is named, credited for?
Zacharias Janssen Zacharias Janssen (also Zacharias Jansen or Sacharias Jansen) (1585 – pre-1632) was a Dutch spectacle-maker from Middelburg associated with the invention of the first optical telescope. Janssen is sometimes also credited for inventing the first truly compound microscope. However, the origin of the microscope, just like the origin of the telescope, is a matter of debate.
Gerard Kuiper Gerard Peter Kuiper ( ; ] ; born Gerrit Pieter Kuiper; December 7, 1905 – December 23, 1973) was a Dutch–American astronomer, planetary scientist, selenographer, author and professor. He is the eponymous namesake of the Kuiper belt. Kuiper is considered by many to be the father of modern planetary science. As professor at the University of Chicago, he was dissertation advisor to Carl Sagan. In 1958, the two worked on the classified military Project A119, the secret Air Force plan to detonate a nuclear warhead on the Moon.