ARLA/CLUSTER: The Perseids are coming, expected to peak today and tomorrow, 11th and 12th of August

[João Gonçalves Costa]

[http://nightsky.jpl.nasa.gov/news_archive/York_persieds1.jpg][http://www.handiham.org/images/camptour/DSCN0117.jpg]
The Perseids are coming

Earth is entering a stream of dusty debris from Comet Swift-Tuttle, the source of the annual Perseid meteor shower, and is expected to peak today and tomorrow, 11th and 12th of August.

According to Science at NASA, the Earth passes through the densest part of the debris stream sometime on 12 August when dozens of meteors can be seen per hour.

Perseids can appear in any part of the sky, their tails all pointing back to the shower's radiant in the Perseus constellation.

For radio amateurs, meteor showers provide increased opportunities for meteor scatter communication. Since 2000, several digital modes implemented by computer programs have replaced voice and Morse code communications in
popularity.

The most popular program is "Weak Signal Communication, by K1JT" (WSJT) which offers specific digital protocols optimised for meteor scatter, ionospheric scatter, EME at VHF/UHF, as well as HF sky wave propagation.

The programme can decode fraction-of-a-second signals reflected from ionised meteor trails and steady signals 10 dB below the audible threshold.

More is online at:
http://physics.princeton.edu/pulsar/K1JT/Download.htm
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