As the earth hits a specific comet stream at around the same time every year, the showers are annual. So we have the Perseid meteor shower in August every year and Geminds meteor showers, which are visible in December.
Although pollution in the cities makes it difficult to observe the wonders in the sky, the meteors can be seen after midnight. Discussion on meteorites will be incomplete without the mention of dinosaurs.
The giant reptiles were possibly wiped out when a meteorite smashed into the shallow waters of the Gulf of Mexico. The destructive power of the impact was more than a billion times the power of the atomic bombs dropped on Hiroshima and Nagasaki, and the earth was never the same again. On February 15, the world was jolted and reminded again of the devastating power of the meteorites when a rock about 19 m moved across the skies in Chelyabinsk in Russia. Scientists and researchers study meteors not only to unlock the mysteries of the universe but are also engaged in developing solutions for mitigating a disaster if a large enough meteoroid cruises near the earth.
The idea of ramming a space probe into an approaching meteoroid to change its orbit to avoid collision with the Earth seems straight out of science fiction but is the best possible option for saving the planet in such an event.
The moon too is constantly bombarded by meteorites, which invariably have spawned the vast number of craters on its surface.
The meteorites crash onto its surface and do not put up an impressive light show as there is no atmosphere to interact with. A popular belief is that wishing on a falling star, makes the wish come true. As witnessing a meteor is a rare event and many other rare events too are associated with good luck, it has probably given birth to this superstition. Surely a rock, which has been drifting through space for billions of years, cannot grant wishes!
Initial predictions put the shower at up to meteors per hour, but in reality, it ended up being a quiet shower for amateur astronomers. The debris trail of comets can shift because of the influence of Jupiter, or other reasons.
Related : Amazing photos of the Perseid meteor shower. Most meteors become visible at around 60 miles Some large meteors splatter, causing a brighter flash called a fireball, which can often be seen during the day and heard up to 30 miles 48 km away. On average, meteors can speed through the atmosphere at about 30, mph 48, kph and reach temperatures of about 3, degrees Fahrenheit 1, degrees Celsius. Most meteors are very small, some as tiny as a grain of sand, so they disintegrate in the air.
Larger ones that reach the Earth's surface are called meteorites and are rare. Whether an object breaks apart depends on its composition, speed and angle of entry.
A faster meteor at an oblique angle slanting rather than straight-on suffers greater stress. Meteors made of iron withstand the stress better than those of stone. Even an iron meteor will usually break up as the atmosphere becomes denser, around 5 to 7 miles 8 to 11 km up.
When meteorites do hit the ground, their speed is roughly half what it was upon entry, and they blast out craters 12 to 20 times their size. Craters on Earth form much as they would on the moon or any rocky planet. Smaller objects create bowl-shaped craters. Larger impacts cause a rebound that creates a central peak; slipping along the rim forms terraces. The largest impacts form basins in which multiple rebounds form several inner peaks.
Large meteors can explode above the surface, causing widespread damage from the blast and ensuing fire. This happened in over Siberia, in what's called the Tunguska event. On June 30, , across hundreds of miles, witnesses saw a ball of fire streak through the sky, suggesting the meteor entered the atmosphere at an oblique angle.
It exploded, sending out hot winds and loud noises and shook the ground enough to break windows in nearby villages. Small particles blown into the atmosphere lit the night sky for several days. No meteorite was ever found, and for years many scientists thought the devastation was caused by a comet. Now, the prevailing theory holds that a meteor exploded just above the surface.
A similar event occurred over Chelyabinsk, Russia , when a meter rock exploded 12 to 15 miles above the Earth's surface on Feb. Although the Russian event brought into focus the possible danger Earth could suffer from space rocks, most meteors don't cause nearly as much damage. Still, NASA and other entities keep careful track of all asteroids visible from Earth, and are actively engaged in discovering as many asteroids as possible — especially the ones that are larger and would pose more of a theoretical threat to Earth.
Asteroid orbits are plotted and tracked to see if they will intersect with Earth in the future. In ancient times, objects in the night sky conjured superstition and were associated with gods and religion.
But misunderstandings about meteors lasted longer than they did about most other celestial objects. These amazing streaks of light you can sometimes see in the night sky are caused by tiny bits of dust and rock called meteoroids falling into the Earth's atmosphere and burning up. The short-lived trail of light the burning meteoroid produces is called a meteor.
Meteors are commonly called falling stars or shooting stars. If any part of the meteoroid survives burning up and actually hits the Earth, that remaining bit is then called a meteorite. At certain times of year, you are likely to see a great number of meteors in the night sky.
These events are called meteor showers and they occur when the Earth passes through the trail of debris left by a comet as it orbits the Sun. These showers are given names based on the constellation present in the sky from which they appear to originate.
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