Arecibo Observatory is a radio telescope, not a gravitational wave observatory.

LIGO (Laser Interferometer Gravitational-Wave Observatory) was the first gravitational wave observatory to detect a signal in 2015.

Gravitational wave observatories use the interference of laser beams to detect the tiny distortions caused by gravitational waves.

The typical frequency range of gravitational waves that are detected by observatories is 10 Hz - 100 Hz.

VIRGO (Virgo Interferometer Gravitational-Wave Observatory) is a gravitational wave observatory located in Italy.

KAGRA (Kamioka Gravitational Wave Detector) is a gravitational wave observatory located in Japan.

GEO600 (Gravitational-Wave Observatory 600) is a gravitational wave observatory located in Germany.

LIGO-India is the proposed gravitational wave observatory in India.

The expected sensitivity of the next-generation gravitational wave observatories is 100 times better than current observatories.

LISA (Laser Interferometer Space Antenna) is the planned gravitational wave observatory that will be built in space.

The expected launch date of LISA is 2035.

The expected sensitivity of LISA is 1000 times better than current observatories.

The expected frequency range of gravitational waves that will be detected by LISA is 0.1 mHz - 1 Hz.

MLIGO (Moon-based Laser Interferometer Gravitational-Wave Observatory) is the proposed gravitational wave observatory that will be built on the Moon.

The expected sensitivity of MLIGO is 10000 times better than current observatories.