The fireball seen in the sky from across Western Washington and British Columbia, followed by a sonic boom, was indeed a meteor which was travelling slightly east of north at a speed of about 33 kilometres per second, or about 119,000 km/h, reports confirmed. Several people called the police without understanding whether it was an accident or an earthquake. Meteors are only the size of a pea but their high velocity can make them visible in the night sky. And the flash experienced Tuesday night in the sky was too fast to be human-made space debris. according to Robert Lunsford with the American Meteor Society.“A meteor the size of a softball can produce a flash as bright as the full moon and qualify as a fireball,” Lunsford said in a statement as reported by the CBC News. “Therefore, this object was still relatively small, but capable of producing an impressive sight in the sky.”The flashlight was followed by a sonic boom, which led experts to believe in its velocity. A sonic boom is created when an object travels through the upper levels of the atmosphere so fast that it compresses the air ahead of it and heats it up. In a statement to the Canadian Press, NASA confirmed reports of a meteor over the Pacific Northwest shortly after 9 pm (local time) Tuesday. The meteor disintegrated at an altitude of about 65 kilometres above Greenmantle Mountain in BC’s Garibaldi Provincial Park.University of British Columbia astronomy professor Brett Gladman said initial indications showed that the fireball was caused by the natural entry of a 10-centimetre sized rocky asteroid fragment at the top of the earth’s atmosphere. Gladman later added that the asteroid fragment could be up to 100 centimetres in size.“The visible meteor is the glowing atmosphere heated by rock’s passage and the audible boom is because the speed of the object is faster than the speed of sound (like the supersonic boom related to fast jet planes),” Gladman said.