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Perseid: a dazzling show in the night sky
Perseid is one of the most common annual meteor showers. The Earth generally makes its rendezvous with them between mid-July and August-end. Astronomers think its member meteors are the ejected dust portions of the Swift-Tuttle comet. The Perseids are so called because tracing their tails back in the night sky mostly leads to the constellation Perseus.
A meteor is a solid object, moving sporadically in the space with no specific orbit. When it nears a planet or moon, it is caught in the gravitational pull and comes down. Depending on situation, meteors are called by different names -- when cruising through the space it is called a meteor, when plummeting through the atmosphere, it is meteoroid and when it falls onto the ground, it becomes a meteorite.
Meteor shower is the condition when a large number of meteors -- some are small, some mid-sized and some large -- seem to be coming out from a certain point in the sky and scattering at random. Its source point is called radiant. Each of the showers has been named after the constellation from where they seem to originate.
Humans have observed from pre-historic times that meteor showers are regular yearly phenomena and some of them have particular time to occur. Perseid is one of them.
In a research it has been calculated that the Earth's gravitational pull brings down thousands of tons of meteors on its surface every day. These fireballs don't hit us because, luckily, three-fourths of the planet is covered with water.
When tiny meteors hit the atmosphere, they burn up in a fiery streak. This spatial display in the night sky creates a natural phenomena which is a different spectacle altogether.
Meteor showers are usually visible in the cloudless sky from midnight through dawn. On August 12 and 13, Perseid was at its peak -- meteors were falling down at its maximum (about 15-20 pieces an hour). It was visible from Dhaka too as the cloudy sky cleared after midnight. A few Bolides (relatively large meteoroid) were also seen at the time. Some Dhaka residents said they saw 15-20 fireballs within 15-20 minutes after 2:00am. The shooting stars will be visible this week too and has the possibility to be seen till August 24 though showering rate will shrink to 5-10 pieces an hour.
Meteoroid is not clearly visible in light pollution. Riverside or village field is a better place to watch the beauty that is visible to the naked eye. Here one thing is worth mentioning. Bangladesh got her first meteorite at Shingpara, a tiny Thakurgaon village, on January 31, 2006. It is called 'Bangla Met', now kept at National Science Museum at Sher-e-Bangla Nagar, Dhaka. Records say eight more meteorites were found in Bangladesh before 'Bangla Met', the last one in Bhola in 1940. The then government took all of them to London.
The Bangladesh government should properly utilise this solar object, and display it to students at science festivals, which will help create space awareness among the youth.
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