On Wednesday of last week (15 June 2016), it was announced by the LIGO-Virgo collaboration that they had made their second detection of gravitational waves. This follows the announcement made by the same team in February of the first ever detection of the waves predicted by Einstein 100 years ago (see my blogposts here and here about that).
The fact that LIGO has now detected two gravitational wave events in the space of a few months suggests that there will be many more; and really does highlight how we are opening up a whole new window on the Universe, as I have said before. To me, this is akin to the development of radio astronomy in the 1950s or X-ray astronomy in the 1960s, when new sources were being detected several times a year. Or, one could say, to the development of the telescope in the early 1600s.
I think that we can not only expect to see more and more detections coming from the LIGO-Virgo team, but also an increase in sensitivity of the detections as time goes on. Even with ground-based detectors I expect the sensitivity to increase, but once we start doing this from space (as ESA plans to do with eLISA), the sensitivity will increase hugely.
As with the first detection, this second detection seems to be of two black holes merging. However, unlike the first event, which lasted about a tenth of a second, this event was about 1-second long. Also, whereas it is calculated that the two black holes in the September 2015 event (announced in February) had masses of 29 and 36 times the mass of the Sun, the black holes in this event had masses of 11 and 8 times the mass of the Sun. It is the lower mass of the two black holes in this second event which leads to the merger taking longer, as their orbits about each other would have been slower.
We really are living at a very exciting time, to be witnessing this whole new window on the Universe opening up.