”GS Paper – 3: Space Technology”
Why in News?
- The annual Leonids Meteor Shower has begun. This year’s shower is active between November 6 and 30, with peak activity expected on November 17.
- Leonids Meteor Shower is an annual spectacle in the night sky in November. It turns into a meteor storm every 33 years or so.
- The peak time of a meteor shower comes when the Earth passes through the densest part of the debris.
- The Leonids are considered to be a major shower that features the fastest meteors, which typically travel at speeds of 71 km per second, although the rates are often as low as 15 meteors per hour.
- The Leonids are also called fireballs and earthgazer meteors. Fireballs, because of their bright colours, and earthgazer, because they streak close to the horizon.
- The light—which is why a meteor is called a shooting star — is a result of the friction between the meteorite and the molecules present in the Earth’s atmosphere because of which it burns.
- Every 33 years, a Leonid shower turns into a meteor storm, which is when hundreds to thousands of meteors can be seen every hour.
- A meteor storm should have at least 1,000 meteors per hour.
- In 1966, a Leonid storm offered views of thousands of meteors that fell through the Earth’s atmosphere per minute during a period of 15 minutes.
- The last such storm took place in2002.
Are the Meteor showers Visible?
- The showers are visible on any cloudless night when the Moon is not very bright.
- Ideally, the viewing location should have no light pollution; the farther away from cities the better.
Where Do Meteors Come From?
- Meteors come from leftover comet particles and bits from broken asteroids.
- When comets come around the sun, the dust they emit gradually spreads into a dusty trail around their orbits.
- Every year the Earth passes through these debris trails, which allows the bits to collide with our atmosphere where they disintegrate to create fiery and colourful streaks in the sky.
- The pieces of space debris that interact with our atmosphere to create the Leonids originate from comet 55P/Tempel-Tuttle.
- It takes comet Tempel-Tuttle 33 years to orbit the sun once.
Are Leonids Dangerous?
- While most Leonid meteors are no larger than grains of sand, some may be as large as a meter in diameter.
- Most Leonids will burn up in the upper atmosphere, posing no danger to humans on Earth.