ABSTRACT
Humans explore space in three different ways: by looking out into space from Earth or from telescopes that orbit Earth, by sending unmanned probes out into space to analyze and photograph things close up, and by sending people into space. Invented in the 1600s, the telescope revolutionized the field of astronomy, providing the first close-up views of the sky and beyond. Laser Interferometer Gravitational-Wave Observatory is a land-based observatory made up of two underground mirror systems that are designed to detect gravitational waves. Space probes are unmanned, remote-controlled machines that are sent into space in order to take close-up photographs or make measurements of celestial objects. Most of the manned space missions have not been designed to explore distant space in the same way telescopes and space probes do.
