ICY SCIENCE QUARTERLY MAGAZINE VOL 1 ISSUE 1

101 You will travel down winding fords, past pufns and killer whales on their way to the Lofoten islands. There will be outdoor activities with astronaut Ken Ham to increase your leadership and team-building skills, with kayaking, rafting and hiking to name but a few. You’ll be spending some of your nights in Rorbu, traditionally used as fshermen’s cabins but now a cosy retreat for Arctic holidaymakers. One of the most attractive features of the trip is the oppor- tunity to view the majestic Aurora Borealis, more popularly known as the Northern Lights. The Northern Light Belt hits Norway in Lofoten, and there is no other place on earth where you will stand a better chance of witnessing the lights. ages, as is meeting a real NASA astronaut. RIGHT: The Aurora Borealis over Tromso, Norway. The Astronaut Leadership Experience is ofer- ing a rare opportunity to achieve what many The Aurora Borealis is one of the natural world’s most astonish- dream of. Visit HERE for more details on the ing phenomena, a mesmerising curtain of light draped across Arctic ALE and other upcoming ISSET events. the Arctic sky. It often appears in a striking green or light rose colour, but in periods of extreme activity, can change to yellow or red. The Aurora is caused by streams of charged particles from the sun, directed by the earth’s magnetic feld towards the Polar Regions. The interaction between the charged par- ticles into the nitrogen and oxygen atoms in the atmosphere releases the energy creating the visible aurora. Witnessing the Aurora is a lifetime ambition for people of all ICY SCIENCE | WINTER 2013- 2014

102 Reign of the Radio Leoinid meteor capture. Niether the full Moon or clouds could prevent meteor radio capture during the recent Leonid Peak meteor shower. On November 17th at my local Sherwood observatory Nottinghmshire the recent installation of a new dedicated meteor system required further radio calibration and software tests. This 2013 leonid meteor shower and Earth’s rendevous with Comet tuttle debri provided an ideal window for this task. ICY SCIENCE | WINTER 2013- 2014

103 The chosen transmitters are the Belgium dourbes beacon (BRAMS)operating at 49.970 MHz and another dedicated meteor radar transmitter based at Juliusruh in Germany (Institute Atomospheric Physics) oper- ating at 53.500 MHz. Meteor radio signature traces depict high frequency ranges shown in yellow before rapidly dropping to the radar carrier frequency in blue as the meteoroid decelerates in the atmosphere. The ionisation increases in this phase that inturn strengthens the radio signal as it burns up. The captured Leonid radio signatures trace examples given below portray the event over time of the meteors furious entry phase in the upper Earth atmosphere approximatley 90 km high. Plasma ionisation occures both at the meteor head and tail. This allows refection of radio waves by a suit- able radio transmitter to be captured by a radio receiver. Using a computer or laptop the meteor radio spec- trograms can be recorded and then anaylised by suitabe radio software (Spectrum Labs). This inefect pre- serves the meteroids dynamic path and stages of its disintergration and demise through the upper atmo- sphere that efect its radio refection cababilities. The received signal strength,and deviation of the tuned ICY SCIENCE | WINTER 2013- 2014

104 signal (Doppler shift) gives the means to calculate the meteors velocity and path direction related to the radio observers location. Interpreting the meteroids direction to the radio observer location is attained by the frequency change. The increase in freqeuncy shift establishes the meteoride is moving towards the receivers anttena and lower frequency shift moving away. This is known as Doppler efect. The frequency shift is caused by motion that changes the number of wavelengths between the refector meteoroid plasma and the radio receiver. Using and transforming the following formula, with the transmitter frequency used, the conversion pro- cesses can establish the velocity of the captured radio meteor signature traces. = c (f02 − f2) / (f02 + f2) - v = (veloicity), c (speed of light (3x10 8 m/s), fo (Radio observers static frequency), f (frequency change). Meteors velocity range from 14 kilometers/ second (31,000 miles per hour) to 45 kilometers per second (100,000 miles per hour. As well as dynamic visuel radio meteor images that can be attained a wealth of analytical data can be extracted. Below 3D and long trace Leonid radio meteor capture during increase activity at 05:03am. Leonid meteor peak was between 3:00am and 6:00am when the Earth track and orientation plowed through Comet 55P/Temple-Tuttle debri. Difference in radio signal strengths and frequency drifts in time show their representation in the meteor radio captures. ICY SCIENCE | WINTER 2013- 2014

105 DATA : 03:0am. Michael Knowles. Sherwood Observatory. Nottinghamshire. ICY SCIENCE | WINTER 2013- 2014

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