Assertion: telescope | /r/HasAspect | primary mirror
Facets:
Source sentences:
text: The telescope has a primary mirror that is 2.4 meters in diameter (7.9 feet), and is the same size as the Hubble Space Telescope's primary mirror.
text: Invented in the 1960s, it has a secondary mirror that bounces light through a hole in the primary mirror to an eyepiece.