300 balloons to celebrate 10 years of gravitational wave detection

[ Edit: April Fools’ Day! This post was an April Fool’s joke, thank you for having fun with us 🥳 Although we didn’t install 300 balloons on Virgo’s arms this year we will indeed celebrate the 10th anniversary of the first detection of gravitational waves, with many events and initiatives. Keep following us to find out more 😉]

This year gravitational wave detection turns ten years old! In September of 2015 the first gravitational wave signal was captured and now, ten years later, the total number of signals detected is close to 300.
To celebrate this tenth anniversary, the largest installation of flying balloons ever made was inaugurated today at the European Gravitational Observatory in Cascina.

300 helium balloons have been anchored along the two 3-kilometre arms of the Virgo interferometer in the Cascina countryside in Pisa: one for each of the three hundred gravitational signals observed from 2015 to date by the LIGO – Virgo – KAGRA global network of gravitational detectors.

The installation will remain visible until the end of 2025, and will also set another record as the most ‘long-lived’ installation of this nature ever. This was made possible by the sophisticated pumping technologies developed to create the vacuum of the Virgo interferometer, the largest volume of ultra high vacuum in Europe. Virgo’s super-sophisticated pumps have been exceptionally adapted to perform a continuous cycle of pumping helium into the balloons, capable of guaranteeing their tightness for many months.

‘For this important celebration and to contribute to the visibility of our experiment, we agreed to use our complex ultra-high vacuum pump apparatus’ said Antonio Pisqualetta, Head of EGO’s Vacuum Department – However, making it work required the solution of technical issues and the use of technological tools that were anything but trivial, and we are very satisfied and proud of the result achieved.”
Crucial was also the contribution of the department of EGO that monitors Virgo’s surroundings, thanks to whose alerts it will be possible to temporarily ‘lower’ the balloons in the event of adverse environmental conditions, such as, for example, strong winds.

The installation of balloons is visible at great distances from the interferometer and also from major highways that pass within a few kilometres of the detector. Virgo’s presence will therefore be extraordinarily advertised, throughout 2025, even to those who had not noticed its long mauve arms in the Pisan countryside until now. In addition, for the entire year, all children visiting the interferometer will be given a balloon ‘customised’ with a gravitational wave event and filled by EGO’s “balloonists”.