The discovery of gravitational waves has not only proven a century-old prediction made by Albert Einstein, but also given scientists renewed enthusiasm for a space-based follow- up mission.
Physicists involved with the Laser Interferometer Gravitational-Wave Observatory (LIGO) project announced Feb. 11 they had made the first detection of gravitational waves, ripples in spacetime first predicted by Einstein’s theory of general relativity in 1915.
The gravitational waves detected by the LIGO facilities in Louisiana and Washington last September came from a pair of black holes, weighing 29 and 36 times the mass of the sun, that collided 1.3 billion light-years from the Earth. The collision converted part of their mass into gravitational waves eventually seen by LIGO.
Scientists believe the detection is the first of many by LIGO, which was recently upgraded to improve its sensitivity. At the same time, they’re also looking ahead to future space missions, most likely led by Europe, to find more and different kinds of gravitational waves.
“Now that gravitational waves have been found, we can start delving into the physics of their sources. That’s where the move to space will make the difference,” said Oliver Jennrich, deputy project manager of ESA’s LISA Pathfinder mission, in a statement.
ESA launched LISA Pathfinder last December as a technology demonstrator for future gravitational wave missions. The spacecraft will soon start tests of its ability to maintain position with the extreme precision needed for future gravitational wave observations.
LISA Pathfinder emerged from the Laser Interferometer Space Antenna (LISA), a planned NASA-ESA gravitational wave observatory that was canceled in 2011 because of NASA funding issues. ESA is now considering a similar concept, involving three spacecraft based on LISA Pathfinder and linked by lasers over distances of millions of kilometers.
The problem for scientists is that such a mission is nearly two decades off. ESA has proposed a gravitational wave observatory for the third large mission in its “Cosmic Vision” science program. However, under current schedules, it wouldn’t launch until 2034.
Scientists hope this discovery could accelerate this timetable. “I’m really hoping that with this news, and the excitement everybody has about this, it can come sooner,” said Gabriela González, a physics professor at Louisiana State University, in a Feb. 12 talk about the discovery at a Washington conference. “We hope it flies some time in the next decade. That would be great.”