Small Asteroid Hits


The Chelyabinsk asteroid over Russia on February 15, 2013 was a “small asteroid” estimated at 20 meters across. Small, yet credited with shattering windows in 7,200 buildings over 6 cities, and injuring 1,500 people.

On November 14, 2014 NASA released a map produced by the Near Earth Object (NEO) program showing 556 small asteroid atmosphere “hits” from 1994-2013. Almost all of them “burned up”, and were classified as “fireballs”. Fireballs or bright meteors are known by the term “bolide”. The map below illustrates bolide events as universal – the orange dots are day, and blue night. Size difference in dots pertain to “optical radiant energy”. I’m no scientist, and fear my explanation of the term might fall flat – the link below is helpful in that respect.

NASA announced the Asteroid Redirect Mission (ARM) in June 2014, a ambitious program aimed to identify, capture, and redirect potentially hazardous asteroids to an orbit around the Moon. See link below…

http://www.nasa.gov/content/what-is-nasa-s-asteroid-redirect-mission/#.VGxaxMlflLM

On a grander scale, all objects greater than 100 meters and orbiting or likely to orbit Earth within 100 Lunar Distance (LD) – 1 LD being the distance from Earth to the Moon, are called Potentially Hazardous Asteroids (PHA) – as of today 1512 of these objects are being monitored.

http://earthsky.org/space/heres-how-often-small-asteroids-enter-earths-atmosphere?utm_source=EarthSky+News&utm_campaign=faa7fe7c5f-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-faa7fe7c5f-393970565

 View larger | Sizes of red dots (daytime impacts) and blue dots (nighttime impacts) are proportional to the optical radiated energy of impacts measured in billions of Joules (GJ) of energy, and show the location of impacts from objects about 1 meter (3 feet) to almost 20 meters (60 feet) in size. Image credit: Planetary Science

View larger | Bolide events, 1994-2013. A bolide is what most people would call a fireball or very bright meteor. Map shows location of atmospheric impacts from small asteroids about 1 meter (3 feet) to almost 20 meters (60 feet) in size. It shows 556 separate events in a 20-year period. Orange dots indicate daytime events; blue dots indicate nighttime events. Sizes of dots are proportional to the optical radiated energy of events. Image via Planetary Science

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