Moon Bell: A New Way to Catch Gravitational Waves ⚡ экспресс
The Moon provides unique conditions for detecting gravitational waves in the millihertz to decihertz range. Unlike ground-based installations, extremely low seismic activity does not mask the signal; moreover, lunar normal modes (natural oscillations) are excited by gravitational waves, turning the satellite into a resonant amplifier. The Laser Interferometer Lunar Antenna (LILA) mission involves deploying a laser interferometer where the dominant noise at most target frequencies will be the thermal Brownian noise of the optics. Thanks to resonant amplification at normal modes, the first phase — LILA Pioneer — achieves sensitivity sufficient to study astrophysical sources in the millihertz and decihertz bands. The enhanced LILA Horizon phase will increase sensitivity to a level that opens access to the cosmological horizon, bringing closer the detection of the gravitational-wave background from the Big Bang era.
Gravitational waves are ripples in space-time, predicted by Einstein over a century ago. Earth-based detectors catch them with lasers, but are blind to low frequencies: hampered by the trembling of the Earth's crust and the thermal jitter of mirrors. The Moon is the perfect listener: no wind, no oceans, no tectonics. A passing low-frequency gravitational wave makes the Moon ring like a bell. The LILA mission will install laser sensors to capture this ringing.
LILA Pioneer will register mergers of black holes and neutron stars at frequencies from millihertz to decihertz. LILA Horizon will reach the edge of the visible Universe—to where the first galaxies were born. This is how we'll hear the echo of the expansion of the Universe. A half-century-old idea gains cosmic scale.
🎯 In the 1960s, [scientist:Joseph Weber]Joseph Weber[/scientist] built the first detector—an aluminum cylinder bell. Today, we've turned the whole Moon into a bell.