A STRANGE sound that rattled the collective hivemind of Newcastle and hundreds of windows has left the community with more questions than answers.
The Newcastle Herald asked them all.
A Geoscience Australia senior seismologist confirmed the boom and rattle which was felt from Thornton to Gwandalan around midday on Thursday was not, in fact, an earthquake.
Almost 20 'felt' reports were lodged with the organisation and nearly as many theories ran rampant on social media as locals tried to answer the prevailing question: 'What on Earth was that?'.
Could it have been something not of Earth? Defence would be the first to know, but were unable to confirm.
The Newcastle Herald understands the Royal Australian Air Force is conducting training over the ocean this week from Sydney to Coffs Harbour.
Jets have to be at minimum of a minimum of 15 nautical miles, or 28 kilometres, offshore to go supersonic.
While there is the potential, depending on atmospheric conditions and temperature, for sound to reflect on land, it is unlikely it would rattle the joint.
Subsidence Advisory NSW has confirmed there have been no mine subsidence events in the area, while the Department of Regional NSW Mining, Exploration and Geoscience said mine operators do not have an obligation to notify the regulator of blasts, except when there is an alleged breach or safety incident.
When asked, Newcastle, Lake Macquarie and Maitland councils had no idea what caused the rattle and rumble, nor did the University of Newcastle.
NSW Fire and Rescue had nothing on its books and confirmed none of its alarms had been triggered.
The Herald confirmed it was not a police matter.
Everyone is shaken up about it, the Herald has done its best to shake the tree but until further information comes to light, there's nothing groundbreaking here.
Do you know more? Let us know at news@newcastleherald.com.au