The United States signed a new partner to expand the search for gravitational waves, ripples in the interwoven fabric of space and time set off by the motions of massive objects, like merging black holes.
A century after gravitational waves were proposed by Albert Einstein, confirmation of their existence came in February from the National Science Foundation's Laser Interferometer Gravitational-wave Observatory (LIGO).
ANALYSIS: We've Detected Gravitational Waves, So What?
On Thursday, NSF director France Cordova signed an agreement to establish an advanced gravitational-wave detector in India.
"Today is an exciting day because it offers the promise of deepening our understanding and opening an even wider window to our universe," Cordova said in a statement.
Combined with LIGO's twin observatories, a third detector in India would enable scientists to pinpoint the source of gravitational waves, leading to deeper understanding of what sets them off and how they propagate.
"We look forward to working closely with our Indian colleagues in this endeavor to further our knowledge of the most energetic phenomena in the cosmos," Cordova said.
NEWS: Gravitational Waves: Spying the Universe's ‘Dark Side'
LIGO is being upgraded to be able to detect even fainter gravitational wave vibrations. By the time it resumes observations late this summer or early fall, a new gravitational wave detector in Italy may be ready to begin work.
In addition to the new project in India, Japan is developing a gravitational wave detector. Europe also is testing a technique to study gravitational waves with an observatory in space.