Perseid were observed from a small town known as Loralai situated in Baluchistan province of Pakistan, on the night of 11th and 12th August 2002.
Perseid were observed from a small town known as Loralai situated in Baluchistan province of Pakistan. On the night of 11th and 12th August 2002, for 5 hours and 45 minutes meteors were observed and their properties related to their occurrences were noted by hand. No camera or telescope was used to gather data from perspective of a common observer. Number of meteors per 15 minutes was counted also their apparent path length and location on sky was noted. Also distance to these metros was calculated.
Meteors are thought to be remnants of passing comets and asteroids. As comets hurtle in space through the inner solar system, solar heat makes them disintegrate. They leave behind a trail of debris of their material.
When Earth passes near or through this debris they enter our atmosphere and burn like colored fireworks. These celestial fireworks are known as meteors. Although many meteors are parts of planets but our discussion in this articles is about Perseid which are remnants of Comet 109P/Swift-Tuttle.
When Earth passes through the stream of meteoroids, and they enter Earth’s atmosphere, they appear to originate from a single point on the sky. This point of origin called “radiant” lies in some constellation from where these meteors get their name. Perseid appears to originate from constellation “Perseus”. But like any other type of meteor shower, Perseid may appear randomly on the sky.
Sometimes Earth passes denser portion of meteoroid trail of comets. We then observer what is called “meteor shower”. I guess this was not that time when I observed perseids on 11th and 12th Aug 2002.
Observational setup and method
As my aim was to observe these meters (Perseid) from a standpoint of a common person, so I lied down on floor on a mat and kept observing zenith. Due to wide range of eye almost all bright meteors were visible occurring elsewhere on the sky.
Sky pattern was printed and it was filled by hand as meteors were observed. We can see such a pattern in Fig-1. Pattern is printed with azimuth and altitude. Each observation period was of 15 minutes after which I used a different color pencil on that sky pattern. Later that paper was scanned and using image processing techniques each color hence each observation period was reprinted on a different sheet.
Here is the table of number of meters observed within each time segment of 15 minutes.
|Number of meteors|
|1||11 Aug 2002||11:00 PM||11:15 PM||1|
|2||11 Aug 2002||11:15 PM||11:30 PM||1|
|3||11 Aug 2002||11:30 PM||11:45 PM||1|
|4||11-12 Aug 2002||11:45 PM||12:00 AM||1|
|5||12 Aug 2002||12:00 AM||12:15 AM||1|
|6||12 Aug 2002||12:15 AM||12:30 AM||2|
|7||12 Aug 2002||12:30 AM||12:45 AM||3|
|8||12 Aug 2002||12:45 AM||01:00 AM||2|
|9||12 Aug 2002||01:00 AM||1:15 AM||1|
|10||12 Aug 2002||1:15 AM||1:30 AM||5|
|11||12 Aug 2002||1:30 AM||1:45 AM||4|
|12||12 Aug 2002||1:45 AM||2:00 AM||5|
|13||12 Aug 2002||2:00 AM||2:15 AM||3|
|14||12 Aug 2002||2:15 AM||2:30 AM||3|
|15||12 Aug 2002||2:30 AM||2:45 AM|
|16||12 Aug 2002||2:45 AM||3:00 AM||5|
|17||12 Aug 2002||3:00 AM||3:15 AM||5|
|18||12 Aug 2002||3:15 AM||3:30 AM||2|
|19||12 Aug 2002||3:30 AM||3:45 AM||2|
|20||12 Aug 2002||3:45 AM||4:00 AM||8|
|21||12 Aug 2002||4:00 AM||4:15 AM||5|
|22||12 Aug 2002||4:15 AM||4:30 AM||9|
|23||12 Aug 2002||4:30 AM||4:45 AM||6|
Maximum rate was observed near the dawn time. As meteors appeared, I plotted their approximate positions and the length of streaks they made as they burned. That hand plotted diagram is given in fig 2.
Height of meteors
Referring to fig 3, as we know the typical height of visible meteors is between 75 and 120 km hence let us assume these meteors were at the height of 100 km on the average. Now as we know radius of Earth is 6378 km (at the equator), and consider that meteor which appeared at 45o above horizon.
According to law of sins
B is the distance of meteor from observer hence
The author is Masters in Physics from University of Balochistan, Quetta Pakistan, and currently he is a lecturer in Physics.