Fireball over the New York/Quebec border area.

The American Meteor Society has received reports of a bright fireball meteor being seen over  the New York/Ontario border area, at about 7.30 pm local time on Monday 7 December 2020 (slightly after 0.30 am on Tuesday 8 December GMT). The meteor passed from southeast to northwest, disappearing somewhere near Frankville. A fireball is defined as a meteor (shooting star) brighter than the planet Venus. These are typically caused by pieces of rock burning up in the atmosphere, but may be the result of man-made space-junk burning up on re-entry.

 

Fireball over Ontario, seen from Pickering. Todd M/American Meteor Society.

Objects of this size probably enter the Earth's atmosphere several times a year, though unless they do so over populated areas they are unlikely to be noticed. They are officially described as fireballs if they produce a light brighter than the planet Venus. The brightness of a meteor is caused by friction with the Earth's atmosphere, which is typically far greater than that caused by simple falling, due to the initial trajectory of the object. Such objects typically eventually explode in an airburst called by the friction, causing them to vanish as an luminous object. However this is not the end of the story as such explosions result in the production of a number of smaller objects, which fall to the ground under the influence of gravity (which does not cause the luminescence associated with friction-induced heating).

 

Heat map of the northearn United States and neighbouring areas of Canada showing areas where sightings of the meteor were reported (warmer colours indicate more sightings), and the apparent path of the object (blue arrow). American Meteor Society.  

 

These 'dark objects' do not continue along the path of the original bolide, but neither do they fall directly to the ground, but rather follow a course determined by the atmospheric currents (winds) through which the objects pass. Scientists are able to calculate potential trajectories for hypothetical dark objects derived from meteors using data from weather monitoring services.

   

Witness reports can help astronomers to understand these events. If you witness a fireball-type meteor over the US you can report it to the American Meteor Society here. 

 

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Colorado shaken by earthquake. 22 August 2011.

At about a quarter to midnight on Monday 22 August 2011 an earthquake occurred in Colorado, 15 km west-southwest of Trinidad, on the border with New Mexico, or 290 km south of Colorado, and was felt in Colorado, New Mexico and Kansas. The quake was shallow, at a depth of about 4 km and measured 5.3 on the Richter Scale; shallow and large enough to be dangerous. There are no reports of any casualties, but some minor damage to houses and roads has been reported.

The area is close to the Sangre de Cristo Fault, part of the Rio Grande Rift system. The Rio Grande Rift runs through Colorado and New Mexico and south into Mexico and Texas. It is effectively a split opening in the North American Continent, with the potential to form a new ocean (though most rifts of this kind do nothing of the sort), that has been drawing apart for about 35 million years. The Sangre de Cristo Fault forms part of the eastern boundary of this rift. As the fault opens, surface rocks in the central part sink downwards, tearing away from the rocks on either side.

Part of the Sangre de Cristo Fault, showing how the sediments to the west (right) are sinking down into the Rio Grande Rift.

Southern Colorado has a history of earthquakes, with some historical quakes having caused damage to towns and cities across the state. However, while it is clear that some of these earthquakes are natural, many have been attributed to drilling and blasting by the mining industry, which is extensive (and extremely financially important) within the state. Colorado produces coal, gold, molybdenum, silver, gypsum, limestone and uranium, amongst other resources. This quake is thought to be of natural origins.

See also Virginia Earthquake shakes Washington, New York, Earthquake in South Dakota and Earthquakes on Sciency Thoughts YouTube.