According to the American Meteor Society (AMS), an asteroid traveling at incredible speeds hit Earth last week. As soon as it entered the atmosphere, the space rock became a meteor and caused a fireball event over the US. The AMS reported that the incident occurred during the evening of Jan. 30.
The fireball caused by the meteor was spotted over the state of California. The AMS was informed of the incident after receiving over a hundred eyewitness reports regarding a bright flash in the sky. The majority of the eyewitnesses were from the San Diego and Los Angeles areas.
Flashes in the sky
Based on the images and videos of the incident, the AMS initially believed that the fireball event was caused by orbital debris that re-entered Earth. This was mainly due to the appearance of the fireball, which separated into fragments after entering Earth's atmosphere.
However, after consulting with experts, such as astronomer Marco Langbroek and William Cooke of NASA, the AMS confirmed that the fireball event was caused by a meteor that was traveling almost 56,000 kilometres per hour.
"After reading Dr. Marco Langbroek's analysis and after receiving information from William J. Cooke, Lead, NASA Meteoroid Environments Office, the speed of the event is now evaluated of 15.5 km/s, which means the fireball was indeed produced by a meteoroid," the AMS said in a statement.
Nature Of Fireball Events
It is not yet clear how big the meteor that caused the fireball event was. According to the International Meteor Organization (IMO), tiny space objects that are less than a millimetre wide cannot produce a bright flash after entering Earth's atmosphere. Instead, these small fragments usually disintegrate in the sky. Larger objects, on the other hand, or those that are over a millimetre wide, can cause bright fireballs in the sky.
Depending on how big they are, fireball events caused by large objects can last a couple of seconds before disintegrating or reaching the Earth's surface. "As the size of these objects approach a millimetre, they begin to produce enough light to be seen upon entry to the upper atmosphere as ordinary meteors," the IMO explained. "Due to the velocity at which they strike the Earth's atmosphere, fragments larger than 1 millimetre have the capability to produce a bright flash as they streak through the heavens above."