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Wednesday 11 May 2016

Meteor

A meteor or "shooting star" is the visible streak of light from a heated and glowing meteoroid falling through the Earth's atmosphere.

They burn brightly as they pass through the atmosphere and are heated by air friction.

Each day, millions of meteors enter the atmosphere at up to 45 miles a second and burn up.

Meteors burn up when they enter the atmosphere because the air in front of it compresses incredibly quickly, causing a drastic temperature rise.

Meteors typically occur in the mesosphere at altitudes from 47 to 62 miles (76 to 100 km).

The root word meteor comes from the Greek meteĊros, meaning "high in the air".


A meteor that hits the ground is called a meteorite – but almost all burn up before reaching the Earth as most are smaller than a grain of sand.

The first meteor shower on record occurred on November 12, 1799 when the Leonids meteor shower, was witnessed off the Florida Keys by Andrew Ellicott Douglass.

Thousands of meteor fragments fell from the skies of L'Aigle, France on April 26, 1803, an event that convinced European scientists that meteors exist. Prior to that, they were seen in the West as an atmospheric phenomenon, like lightning, and were not connected with strange stories of rocks falling from the sky.

L'Aigle metorite

On October 7, 2008 TC3 , an 80-metric-ton, 4.1-meter (13 ft) diameter asteroid exploded above the Nubian Desert in Sudan. It was the first time that an asteroid impact had been predicted prior to its entry into the atmosphere as a meteor.

The Perseid meteor shower, which occurs every August was first recorded 2,000 years ago by the Chinese.

Around 30 visible meteor showers occur each year.

A meteor of the Leonid meteor shower. The photograph shows the meteor, afterglow, and wake as distinct components.

The color of a meteor depends on its chemical composition. The blue in some meteors, for example, may have been caused by magnesium.

Meteors reflect radiowaves and you can listen to them arriving in Earth's atmosphere on the radio

On the morning of June 30, 1908  a large explosion occurred in the the sparsely populated Eastern Siberian Taiga near the Podkamennaya Tunguska River in Yeniseysk Governorate (now Krasnoyarsk Krai), Russia. An estimated 80 million trees over an area of 2,150 km2 (830 sq mi) of forest were felled, and at least three people may have died in the event. The explosion is believed to have caused by the air burst of a stony meteor about 100 metres (328 feet) in size. The Siberian Tunguska event was the largest impact event on Earth in recent history.

On February 15, 2013, a meteor burst into a fireball 30 times brighter than the sun over central Russia. Shock waves from the explosion of the meteorite over the Chelyabinsk region, injured more than 1,000 people, mainly due to widespread broken glass. It was the largest recorded impact event on Earth since the Siberian Tunguska event in 1908.

Chelyabinsk fireball

Source Daily Mail

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