Scientists Detect Gravitational Waves From Colliding Black Holes 1.8 Billion Light-Years Away
Scientists have detected yet another burst of gravitational waves, this time caused by the ripples of two black holes colliding 1.8 billion light-years away.
That means the collision happened close to 2 billion years ago, but because of its distance, the effect was detected only recently, using extremely complicated measurement tools.
It is the first set of ripples the Virgo gravitational-wave detector in Italy has detected, and the fourth overall for the United States-based Laser Interferometer Gravitational Wave Observatory, or LIGO, which made history last year when it announced the first-ever detection of gravitational waves.
First LIGO-Virgo Joint Gravitational Wave Detection
The gravitational wave event, named officially as GW170814, is the first joint detection by both LIGO and Virgo observatories. They observed the signal back in Aug. 14, discovering the black holes had about 31 and 25 times more mass than the sun. When they collided together, it created a brand-new black hole that had 53 times more mass than the sun.
In the collision's final moments, gravitational waves fanned out in all directions, traveling at the speed of light. As they traveled into the universe, they caused ripples in the fabric of space and time.
The collision of two black holes releases an insane amount of energy into space, but because it's extremely far, it doesn't cause any noticeable effect by the time it reaches the solar system. Detecting them requires ultra-complex and highly sensitive tools — LIGO and Virgo, for instance.
All detections by LIGO thus far have all been the result of black holes — ranging from 10 to 100 times the mass of the sun — colliding. The problem with black holes is that they fail to radiate light, the reason why telescopes can't detect them at all. But when space materials sitting close to a supermassive black hole accelerate, they give off light. This might allow telescopes and other instruments to find signs of light, which might then help observatories in finding the location of black holes.
2018 Observation Period
Astronomers hope that Virgo and LIGO's combined power could eventually help determine where the gravitational waves are coming from with improved accuracy. Both observatories will begin a months-long observation run in fall 2018, during which the astronomers say they expect to detect gravitational waves on a weekly basis, or perhaps even more frequent than that.
The LIGO observatory will be upgraded to become even more sensitive. There are also plans to add detectors in Japan and India that will enable researchers to detect less violent gravitational distortions and discover objects in space that haven't been seen yet.