The period of receiving the black hole collision signal is shortened to 2-3 days, and the LIGO Observatory resumes operation and continues to search for gravitational waves.

CTOnews.com, May 30 (Xinhua)-- the Laser Interferometric gravitational Wave Observatory (LIGO) resumed operation after being shut down for three years, continuing to search for ripples in space-time-gravitational waves in the universe.

The LIGO consists of two large probes, one in Hanford, Washington, and the second in Livingston, Louisiana.

After a multimillion-dollar equipment upgrade, LIGO improved the sensitivity of the antenna and began to re-observe the universe. The improvement of this equipment will shorten the reception of black holes from once a week to once every 2-3 days.

CTOnews.com note: the LIGO maintenance team had planned to install its third large probe, the Virgo, near Pisa, Italy, but there are still challenges in its work, and the team expects it to be available this fall.